United States · Multi-region weather view
Sonoma & Mendocino
Sign in to followNorth Coast valleys from Sonoma through Mendocino and Anderson Valley.
Fog and Pacific air cool the western valleys, while vineyards farther inland receive more heat.
Climate comparisons use the 1991–2020 combined regional record · updated through Aug 20, 2026.
Current conditions
Observations through Aug 31, 2026 · 00:30 UTC
Temperature27.1°C
Dew Point9.8°C
Relative Humidity34%
24h Rainfall0.0 mmmodeled IFS total through Aug 29
NWS station average · 2 stations
Temperature, dew point, humidity, and wind are averaged using the same locations and weights as the historical record. The current temperature uses 100% of the configured regional weight.
- BNVC1 — BOONVILLE · 50% regional weight
- KSTS — Santa Rosa, Santa Rosa Sonoma County Airport · 50% regional weight
NOAA National Weather Service observations. Station readings are point measurements and may not represent every vineyard elevation or exposure.
Vintage explorer
Mean temperature16.2°C
Temperature anomaly-0.7°Cvs 1991-2020
Growing degree days1363base 10°C
Hot days11≥ 32°C
What stood out in 1999
Frost exposure can vary sharply from one site to the next.
Spring frost recorded · Low confidence
The regional record had 2 spring day(s) at or below 0°C.
Frost exposure can vary sharply from one site to the next.
How unusual was 1999?
The ranking compares vintages that meet the data-coverage threshold and use the same source, regional rules, and 1991-2020 baseline.
Growing-season temperature
3rd coolest of 35 vintages Cooler than 32 of 34 other vintages 16.2°CGrowing-season rainfall
9th driest of 35 vintages Drier than 26 of 34 other vintages 124.8 mmHeat accumulation
4th lowest of 35 vintages Lower than 31 of 34 other vintages 1363 GDDHot days
17th most of 35 vintages More than 15 of 34 other vintages 11 days1999 month by month
Compared with 1991–2020
Follow heat accumulation, rainfall, frost exposure, and the region’s growing and harvest windows in calendar order.
Frost watch
Growing season
Harvest window
-
1–31 Frost watchHeat accumulation
1999 0 GDDTypical 52 GDDRainfall
1999 167.6 mmTypical 146.6 mm- 1999 freezing days
- 0
- Typical
- 0.4
Heat accumulation ran behind the typical month.
-
1–30 Frost watchGrowing seasonHeat accumulation
1999 77 GDDTypical 81 GDDRainfall
1999 74.2 mmTypical 73.1 mm- 1999 freezing days
- 2
- Typical
- 0.2
More freezing days than the typical month.
-
1–31 Frost watchGrowing seasonHeat accumulation
1999 101 GDDTypical 154 GDDRainfall
1999 8.2 mmTypical 40.0 mm- 1999 freezing days
- 0
- Typical
- 0.0
Heat accumulation ran behind the typical month.
-
1–30 Growing seasonHeat accumulation
1999 196 GDDTypical 229 GDDRainfall
1999 3.0 mmTypical 12.7 mmClose to the typical monthly pattern.
-
1–31 Growing seasonHeat accumulation
1999 244 GDDTypical 294 GDDRainfall
1999 1.0 mmTypical 1.5 mmClose to the typical monthly pattern.
-
1–31 Growing seasonHeat accumulation
1999 284 GDDTypical 297 GDDRainfall
1999 2.5 mmTypical 2.5 mmClose to the typical monthly pattern.
-
1–30 Growing seasonHarvest windowHeat accumulation
1999 264 GDDTypical 263 GDDRainfall
1999 1.5 mmTypical 5.9 mmClose to the typical monthly pattern.
-
1–31 Growing seasonHarvest windowHeat accumulation
1999 196 GDDTypical 178 GDDRainfall
1999 34.4 mmTypical 52.4 mmClose to the typical monthly pattern.
View milestone calendar data as a table
| Month | 1999 GDD | Typical GDD | 1999 rainfall | Typical rainfall | 1999 freezing days | Typical freezing days |
|---|---|---|---|---|---|---|
| March 1999 | 0 GDD | 52 GDD | 167.6 mm | 146.6 mm | 0 | 0.4 |
| April 1999 | 77 GDD | 81 GDD | 74.2 mm | 73.1 mm | 2 | 0.2 |
| May 1999 | 101 GDD | 154 GDD | 8.2 mm | 40.0 mm | 0 | 0.0 |
| June 1999 | 196 GDD | 229 GDD | 3.0 mm | 12.7 mm | Outside frost window | Outside frost window |
| July 1999 | 244 GDD | 294 GDD | 1.0 mm | 1.5 mm | Outside frost window | Outside frost window |
| August 1999 | 284 GDD | 297 GDD | 2.5 mm | 2.5 mm | Outside frost window | Outside frost window |
| September 1999 | 264 GDD | 263 GDD | 1.5 mm | 5.9 mm | Outside frost window | Outside frost window |
| October 1999 | 196 GDD | 178 GDD | 34.4 mm | 52.4 mm | Outside frost window | Outside frost window |
Calendar data and method
Monthly values are weighted across every configured regional sample using stored Google ARCO ERA5 daily reanalysis. “Typical” is the mean monthly total across 30 baseline seasons. GDD is counted only inside the configured growing window; freezing days are counted only inside the frost-watch window; rainfall covers every displayed calendar day.
Selected-vintage coverage is 100%. Source rows were last retrieved Aug 20, 2026.
Replay the 1999 growing season
214 daily regional observations
Move through the season to follow temperature, rainfall, accumulated heat, and recorded weather events day by day.
Mean temperature
Daily rainfall
Season GDD
Season rainfall
No detected event on this date.
Replay data and method
Daily values are weighted across every configured regional sample using stored Google ARCO ERA5 reanalysis. Coverage is 100%. Source rows were last retrieved Aug 20, 2026.
Closest weather matches
These years had the most similar growing-season and harvest weather.
Closest match
2012
Most alike in Spring frost exposure and Growing degree days.
- Spring frost exposure
- the same: 0 days
- Growing degree days
- higher: 31 GDD
Largest difference: Hot-day count — fewer hot days
View 2012 →Second closest
2009
Most alike in Hot-day count and Spring frost exposure.
- Hot-day count
- the same: 0 days
- Spring frost exposure
- the same: 0 days
Largest difference: Harvest precipitation — more rain
View 2009 →Third closest
2008
Most alike in Spring frost exposure and Harvest precipitation.
- Spring frost exposure
- the same: 0 days
- Harvest precipitation
- more rain: 12.1 mm
Largest difference: Hot-day count — more hot days
View 2008 →
How similar years are calculated
Method analog-v1-2026-07 standardizes six weather measures across 34 complete ARCO ERA5 comparison years, then measures the distance between them. The calculation runs when the page is requested.
Measures used: Growing-season mean temperature (20%); Growing degree days (15%); Hot-day count (15%); Growing-season precipitation (20%); Harvest precipitation (20%); Spring frost exposure (10%).
Calculated distances: 2012 0.535; 2009 0.700; 2008 0.736.
View historical chart data as a table
| Year | Temperature anomaly | Rainfall anomaly | Hot days |
|---|---|---|---|
| 1991 | -0.4°C | -55 mm | 6 |
| 1992 | +0.9°C | +6 mm | 6 |
| 1993 | +0.1°C | +44 mm | 10 |
| 1994 | -0.3°C | -52 mm | 3 |
| 1995 | -0.2°C | +23 mm | 14 |
| 1996 | +0.1°C | +50 mm | 15 |
| 1997 | +0.5°C | +15 mm | 7 |
| 1998 | -0.6°C | +61 mm | 17 |
| 1999 | -0.7°C | -63 mm | 11 |
| 2000 | -0.2°C | +61 mm | 9 |
| 2001 | +0.1°C | -86 mm | 16 |
| 2002 | -0.4°C | -132 mm | 18 |
| 2003 | +0.1°C | +60 mm | 21 |
| 2004 | +0.3°C | -25 mm | 12 |
| 2005 | -0.4°C | +101 mm | 6 |
| 2006 | -0.0°C | +38 mm | 14 |
| 2007 | -0.7°C | +10 mm | 4 |
| 2008 | -0.2°C | -123 mm | 17 |
| 2009 | -0.4°C | +11 mm | 11 |
| 2010 | -1.1°C | +266 mm | 9 |
| 2011 | -0.7°C | +64 mm | 6 |
| 2012 | -0.5°C | -39 mm | 5 |
| 2013 | +0.1°C | -63 mm | 11 |
| 2014 | +0.9°C | -59 mm | 15 |
| 2015 | +0.9°C | -96 mm | 15 |
| 2016 | +0.3°C | +83 mm | 8 |
| 2017 | +0.7°C | -18 mm | 20 |
| 2018 | +0.0°C | -1 mm | 2 |
| 2019 | +0.6°C | +0 mm | 13 |
| 2020 | +1.4°C | -82 mm | 18 |
| 2021 | +0.5°C | +72 mm | 14 |
| 2022 | +0.4°C | -4 mm | 11 |
| 2023 | +0.1°C | -83 mm | 10 |
| 2024 | +0.9°C | -89 mm | 23 |
| 2025 | +0.2°C | -67 mm | 3 |
| 2026 | +0.4°C | -70 mm | 4 |
winter
7.8°C
-1.2°C vs baseline
547 mm rain · -37 mm
spring
11.2°C
-1.6°C vs baseline
249 mm rain · -10 mm
summer
17.9°C
-1.0°C vs baseline
6 mm rain · -10 mm
harvest
17.6°C
+0.3°C vs baseline
35 mm rain · -22 mm
Weather events
Periods that crossed one of the published regional thresholds, shown in date order.
Spring frost exposure
- Minimum temperature
- -0.2°C
- Duration
- 1 day
- Severe-freeze days
- 0 days
The regional model recorded freezing temperatures during spring.
Spring frost exposure
- Minimum temperature
- -0.7°C
- Duration
- 1 day
- Severe-freeze days
- 0 days
The regional model recorded freezing temperatures during spring.
Dry spell
- Duration
- 20 days
- Total rain
- 1.1 mm
- Daily cutoff
- 1.0 mm/day
Dry spell
- Duration
- 25 days
- Total rain
- 0.6 mm
- Daily cutoff
- 1.0 mm/day
Dry spell
- Duration
- 124 days
- Total rain
- 6.9 mm
- Daily cutoff
- 1.0 mm/day
Heat episode
- Peak temperature
- 32.6°C
- Duration
- 3 days
- Heat accumulation
- 38 GDD
Heat episode
- Peak temperature
- 36.6°C
- Duration
- 2 days
- Heat accumulation
- 28 GDD
Heat episode
- Peak temperature
- 35.0°C
- Duration
- 2 days
- Heat accumulation
- 28 GDD
Heat episode
- Peak temperature
- 33.6°C
- Duration
- 3 days
- Heat accumulation
- 36 GDD
Dry spell
- Duration
- 20 days
- Total rain
- 0.1 mm
- Daily cutoff
- 1.0 mm/day
Concentrated harvest rain
- Total rain
- 31.7 mm
- Highest 3-day total
- 31.7 mm
- Trigger threshold
- 20.0 mm
A large share of the season's rain fell during the harvest period.
How events are detected
Weather & Vines combined regional series; method event-timeline-v2-2026-07, rules sonoma-county-catalog-v1-2026-07. Source last updated Aug 1, 2026, calculated Aug 29, 2026. Each configured point must have at least 95.0% coverage.
1991–present
Climate change
Measured regional trends are shown separately from model projections. The observed record ends at the latest complete growing season shared by every published region.
Observed record
Historical trends, 1991–2025
Growing degree days changed +47.5 GDD per decade. The 95% interval is +14.2 to +80.8 GDD per decade, based on 35 eligible vintages.
Weighted median: 70% SSP2-4.5 · 15% SSP1-2.6 · 15% SSP3-7.0
Shaded central 80% model range using the same weights.
How it is measured: Across the April 1–October 31 growing season, each day's mean temperature above 10°C adds to the total; cooler days add zero.
Scroll horizontally to inspect the full timeline.
View annual growing degree days data
| Vintage | Growing degree days | Change from 1991–2020 |
|---|---|---|
| 1991 | 1393 GDD | -102 GDD |
| 1992 | 1672 GDD | +177 GDD |
| 1993 | 1498 GDD | +2 GDD |
| 1994 | 1420 GDD | -75 GDD |
| 1995 | 1455 GDD | -41 GDD |
| 1996 | 1520 GDD | +24 GDD |
| 1997 | 1591 GDD | +96 GDD |
| 1998 | 1370 GDD | -125 GDD |
| 1999 | 1363 GDD | -132 GDD |
| 2000 | 1447 GDD | -48 GDD |
| 2001 | 1528 GDD | +33 GDD |
| 2002 | 1410 GDD | -86 GDD |
| 2003 | 1518 GDD | +23 GDD |
| 2004 | 1550 GDD | +54 GDD |
| 2005 | 1400 GDD | -95 GDD |
| 2006 | 1487 GDD | -9 GDD |
| 2007 | 1353 GDD | -142 GDD |
| 2008 | 1456 GDD | -40 GDD |
| 2009 | 1408 GDD | -87 GDD |
| 2010 | 1282 GDD | -213 GDD |
| 2011 | 1343 GDD | -152 GDD |
| 2012 | 1394 GDD | -101 GDD |
| 2013 | 1506 GDD | +10 GDD |
| 2014 | 1692 GDD | +197 GDD |
| 2015 | 1689 GDD | +193 GDD |
| 2016 | 1552 GDD | +57 GDD |
| 2017 | 1649 GDD | +154 GDD |
| 2018 | 1501 GDD | +5 GDD |
| 2019 | 1623 GDD | +127 GDD |
| 2020 | 1792 GDD | +296 GDD |
| 2021 | 1583 GDD | +88 GDD |
| 2022 | 1578 GDD | +83 GDD |
| 2023 | 1536 GDD | +40 GDD |
| 2024 | 1685 GDD | +190 GDD |
| 2025 | 1533 GDD | +37 GDD |
- Growing-season mean temperature
- +0.22 °C per decade 95% interval +0.06 to +0.39
- Growing degree days
- +47.49 GDD per decade 95% interval +14.17 to +80.81
- Growing-season precipitation
- -11.39 mm per decade 95% interval -28.29 to +5.52
- Hot days
- +0.71 days per decade 95% interval -0.73 to +2.14
- Spring frost days
- +0.08 days per decade 95% interval -0.16 to +0.32
- Longest dry spell
- -4.44 days per decade 95% interval -10.97 to +2.09
Last Updated August 20, 2026
Model ensemble
Projected climate through 2075
Temperature changes are relative to each model’s 1991–2020 baseline. The table combines all three pathways, weighted 70% to SSP2-4.5 and 15% each to SSP1-2.6 and SSP3-7.0.
Scroll horizontally to compare all columns.
| Period | Weighted median | Weighted central 80% | Models per pathway |
|---|---|---|---|
| 2021-2040 | +0.9°C | +0.5 to +1.3°C | 25 |
| 2041-2060 | +1.3°C | +1.0 to +2.1°C | 25 |
| 2061-2075 | +1.8°C | +1.4 to +2.7°C | 25 |
How pathways are combined
For each period and percentile, Weather & Vines takes 70% of the SSP2-4.5 value, 15% of the SSP1-2.6 value, and 15% of the SSP3-7.0 value. Each pathway contains the same 25 models. The weights are an editorial view of the current trajectory, not scenario probabilities.
Last Updated June 29, 2025
Typical year · 1991–2020
When to visit
This calendar describes typical regional weather under the selected climate baseline. It is not a forecast for a future trip, and it does not account for crowds, lodging, events, or vineyard access.
Deterministic IFS forecast
Next ten days
Scroll horizontally to see all forecast dates.
| Date | Sun | Mon | Tue | Wed | Thu | Fri | Sat | Sun | Mon | Tue |
|---|---|---|---|---|---|---|---|---|---|---|
| High | 27°C | 23°C | 18°C | 19°C | 20°C | 22°C | 23°C | 28°C | 26°C | 24°C |
| Low | 11°C | 11°C | 11°C | 11°C | 11°C | 12°C | 10°C | 10°C | 11°C | 16°C |
| Rain | 0.0 mm | 0.0 mm | 1.1 mm | 1.5 mm | 0.0 mm | 0.0 mm | 0.0 mm | 0.0 mm | 0.0 mm | 14.8 mm |
Across the typical year: Late July has the warmest median afternoon high (27.5°C); Late December has the coolest (12.8°C). Wet days are most frequent in Early December (50%) and least frequent in Early August (0%). Ties are resolved by calendar order.
Afternoon highOvernight lowMiddle 50%
Scroll horizontally to inspect all 24 half-month periods.
Scroll horizontally to inspect all 24 half-month periods.
View all 24 periods as a table
Scroll horizontally to view all columns.
| Period | Afternoon high, median (middle 50%) | Overnight low, median (middle 50%) | Wet-day frequency | Period rain, median (middle 50%) |
|---|---|---|---|---|
| Jan 1–15 | 13.0°C (11.3–14.8°C) | 3.9°C (1.2–6.1°C) | 45% | 70.2 mm (21.5–110.1 mm) |
| Jan 16–31 | 13.8°C (12.2–16.1°C) | 4.2°C (1.7–6.6°C) | 46% | 92.8 mm (24.9–163.3 mm) |
| Feb 1–15 | 14.9°C (12.9–18.0°C) | 4.5°C (2.3–7.2°C) | 41% | 62.3 mm (33.4–140.0 mm) |
| Feb 16–29 | 14.1°C (11.9–17.5°C) | 4.8°C (2.5–6.4°C) | 48% | 89.2 mm (30.2–143.3 mm) |
| Mar 1–15 | 16.0°C (13.4–19.3°C) | 5.0°C (2.8–7.2°C) | 44% | 71.7 mm (22.2–89.8 mm) |
| Mar 16–31 | 16.7°C (14.2–19.9°C) | 5.7°C (3.7–7.4°C) | 40% | 41.0 mm (25.6–98.0 mm) |
| Apr 1–15 | 17.2°C (14.8–19.9°C) | 5.6°C (3.7–7.4°C) | 34% | 33.4 mm (15.6–64.3 mm) |
| Apr 16–30 | 19.2°C (16.8–22.8°C) | 6.9°C (5.0–8.2°C) | 27% | 20.6 mm (11.8–43.9 mm) |
| May 1–15 | 20.7°C (18.4–23.7°C) | 7.7°C (6.3–9.1°C) | 18% | 9.8 mm (2.1–25.9 mm) |
| May 16–31 | 21.8°C (19.5–24.7°C) | 8.7°C (7.4–9.9°C) | 18% | 6.9 mm (1.5–36.7 mm) |
| Jun 1–15 | 23.8°C (21.5–26.4°C) | 9.8°C (8.4–10.9°C) | 8% | 2.8 mm (0.5–6.1 mm) |
| Jun 16–30 | 25.8°C (23.8–28.3°C) | 10.4°C (9.0–11.9°C) | 6% | 0.4 mm (0.2–4.2 mm) |
| Jul 1–15 | 27.2°C (25.4–29.1°C) | 11.0°C (10.1–12.1°C) | 0% | 0.4 mm (0.2–0.5 mm) |
| Jul 16–31 | 27.5°C (25.3–29.4°C) | 11.7°C (10.8–12.5°C) | 1% | 0.6 mm (0.4–0.9 mm) |
| Aug 1–15 | 27.4°C (25.5–29.6°C) | 11.4°C (10.4–12.4°C) | 0% | 0.6 mm (0.4–0.8 mm) |
| Aug 16–31 | 27.4°C (25.5–29.5°C) | 11.4°C (10.3–12.5°C) | 1% | 0.6 mm (0.4–1.1 mm) |
| Sep 1–15 | 26.7°C (24.5–29.8°C) | 10.9°C (9.7–12.1°C) | 2% | 0.7 mm (0.4–1.0 mm) |
| Sep 16–30 | 26.4°C (23.6–29.1°C) | 10.3°C (9.0–11.4°C) | 6% | 1.4 mm (0.4–3.7 mm) |
| Oct 1–15 | 24.1°C (21.2–27.1°C) | 9.1°C (7.2–10.5°C) | 12% | 3.7 mm (0.7–23.9 mm) |
| Oct 16–31 | 21.7°C (19.0–24.6°C) | 7.9°C (6.2–9.5°C) | 20% | 15.9 mm (1.8–46.9 mm) |
| Nov 1–15 | 18.1°C (15.9–21.2°C) | 6.2°C (4.2–8.5°C) | 30% | 22.3 mm (11.6–76.6 mm) |
| Nov 16–30 | 15.3°C (13.7–17.3°C) | 4.8°C (2.5–7.3°C) | 40% | 52.4 mm (28.4–97.6 mm) |
| Dec 1–15 | 13.7°C (12.1–15.4°C) | 3.7°C (1.4–7.3°C) | 50% | 101.5 mm (35.6–141.8 mm) |
| Dec 16–31 | 12.8°C (11.1–14.5°C) | 2.9°C (0.9–5.2°C) | 42% | 82.9 mm (20.7–152.7 mm) |
Each year contributes to temperature or rain separately when at least 90% of that period’s days are present. A value is shown only when at least 80% of the baseline years qualify. February 29 is included in late February.
Historical climatology Last Updated August 20, 2026
Season to date
Growing season heat and rainfall
Apr 1–Aug 29, 2026
Growing degree days1070.1base 10°C
Growing-season rainfall118.6 mmweighted regional total
2026 season1991–2020 average
2026 season1991–2020 average
View growing-season accumulation data
| Date | Season GDD | 1991–2020 average GDD | Season rainfall | 1991–2020 average rainfall |
|---|---|---|---|---|
| 2026-04-01 | 2.2 | 2.4 | 5.5 mm | 2.9 mm |
| 2026-04-02 | 3.0 | 4.6 | 8.1 mm | 4.6 mm |
| 2026-04-03 | 6.8 | 6.5 | 8.1 mm | 6.6 mm |
| 2026-04-04 | 12.9 | 8.2 | 8.1 mm | 9.8 mm |
| 2026-04-05 | 19.6 | 9.9 | 8.1 mm | 12.5 mm |
| 2026-04-06 | 23.9 | 11.9 | 8.2 mm | 17.2 mm |
| 2026-04-07 | 28.2 | 13.9 | 8.2 mm | 22.1 mm |
| 2026-04-08 | 34.0 | 15.7 | 8.4 mm | 25.6 mm |
| 2026-04-09 | 39.1 | 17.5 | 9.2 mm | 27.3 mm |
| 2026-04-10 | 43.4 | 19.6 | 17.6 mm | 29.0 mm |
| 2026-04-11 | 44.6 | 21.6 | 34.6 mm | 33.4 mm |
| 2026-04-12 | 45.3 | 23.9 | 54.0 mm | 39.2 mm |
| 2026-04-13 | 46.5 | 26.2 | 57.2 mm | 42.4 mm |
| 2026-04-14 | 48.1 | 28.2 | 57.8 mm | 43.6 mm |
| 2026-04-15 | 49.7 | 30.0 | 57.9 mm | 45.0 mm |
| 2026-04-16 | 51.5 | 32.3 | 58.0 mm | 48.7 mm |
| 2026-04-17 | 54.0 | 35.1 | 58.0 mm | 51.9 mm |
| 2026-04-18 | 57.5 | 37.7 | 58.0 mm | 53.3 mm |
| 2026-04-19 | 61.2 | 40.6 | 58.3 mm | 55.0 mm |
| 2026-04-20 | 63.1 | 43.9 | 75.1 mm | 57.2 mm |
| 2026-04-21 | 64.9 | 47.1 | 90.5 mm | 58.7 mm |
| 2026-04-22 | 67.4 | 50.7 | 98.0 mm | 60.6 mm |
| 2026-04-23 | 69.9 | 54.2 | 98.3 mm | 62.6 mm |
| 2026-04-24 | 73.4 | 57.8 | 98.6 mm | 64.7 mm |
| 2026-04-25 | 75.7 | 61.2 | 98.6 mm | 67.1 mm |
| 2026-04-26 | 77.4 | 64.8 | 99.1 mm | 67.8 mm |
| 2026-04-27 | 80.1 | 68.5 | 99.7 mm | 69.3 mm |
| 2026-04-28 | 83.6 | 72.4 | 99.8 mm | 70.9 mm |
| 2026-04-29 | 88.3 | 76.5 | 99.8 mm | 72.5 mm |
| 2026-04-30 | 94.1 | 80.8 | 99.8 mm | 73.1 mm |
| 2026-05-01 | 99.5 | 85.2 | 99.8 mm | 75.1 mm |
| 2026-05-02 | 104.5 | 89.7 | 99.8 mm | 76.6 mm |
| 2026-05-03 | 108.4 | 94.2 | 99.8 mm | 78.1 mm |
| 2026-05-04 | 111.0 | 98.4 | 102.2 mm | 79.5 mm |
| 2026-05-05 | 115.4 | 102.5 | 104.6 mm | 81.0 mm |
| 2026-05-06 | 121.7 | 106.4 | 104.8 mm | 81.5 mm |
| 2026-05-07 | 128.1 | 110.9 | 104.8 mm | 82.5 mm |
| 2026-05-08 | 134.3 | 115.6 | 105.2 mm | 83.8 mm |
| 2026-05-09 | 140.3 | 119.8 | 105.2 mm | 84.7 mm |
| 2026-05-10 | 148.0 | 124.2 | 105.4 mm | 85.2 mm |
| 2026-05-11 | 156.5 | 128.6 | 105.4 mm | 85.6 mm |
| 2026-05-12 | 163.3 | 132.9 | 105.5 mm | 86.6 mm |
| 2026-05-13 | 168.8 | 137.2 | 105.5 mm | 87.4 mm |
| 2026-05-14 | 175.0 | 142.0 | 105.5 mm | 88.3 mm |
| 2026-05-15 | 181.0 | 147.1 | 105.5 mm | 90.8 mm |
| 2026-05-16 | 186.8 | 152.0 | 105.5 mm | 93.5 mm |
| 2026-05-17 | 191.8 | 157.0 | 105.5 mm | 95.6 mm |
| 2026-05-18 | 199.0 | 162.0 | 105.5 mm | 99.3 mm |
| 2026-05-19 | 206.9 | 167.0 | 105.5 mm | 100.8 mm |
| 2026-05-20 | 216.0 | 172.0 | 105.5 mm | 101.7 mm |
| 2026-05-21 | 224.5 | 177.1 | 105.5 mm | 103.3 mm |
| 2026-05-22 | 231.6 | 182.6 | 105.5 mm | 103.6 mm |
| 2026-05-23 | 237.7 | 188.3 | 105.7 mm | 104.3 mm |
| 2026-05-24 | 243.3 | 193.8 | 105.7 mm | 104.8 mm |
| 2026-05-25 | 247.1 | 199.3 | 105.8 mm | 105.9 mm |
| 2026-05-26 | 251.1 | 204.6 | 106.2 mm | 107.3 mm |
| 2026-05-27 | 255.0 | 210.1 | 106.7 mm | 108.8 mm |
| 2026-05-28 | 260.6 | 215.7 | 111.1 mm | 110.3 mm |
| 2026-05-29 | 266.1 | 221.6 | 111.3 mm | 111.6 mm |
| 2026-05-30 | 271.6 | 227.9 | 111.3 mm | 112.4 mm |
| 2026-05-31 | 278.6 | 234.7 | 111.3 mm | 113.1 mm |
| 2026-06-01 | 287.2 | 241.7 | 111.3 mm | 113.5 mm |
| 2026-06-02 | 294.9 | 248.6 | 111.3 mm | 113.6 mm |
| 2026-06-03 | 303.5 | 255.5 | 111.3 mm | 114.4 mm |
| 2026-06-04 | 311.4 | 262.1 | 111.3 mm | 116.2 mm |
| 2026-06-05 | 319.4 | 268.5 | 111.3 mm | 116.8 mm |
| 2026-06-06 | 325.7 | 274.4 | 111.3 mm | 117.1 mm |
| 2026-06-07 | 331.4 | 280.7 | 111.3 mm | 117.2 mm |
| 2026-06-08 | 336.6 | 287.4 | 112.5 mm | 118.4 mm |
| 2026-06-09 | 344.2 | 294.6 | 114.7 mm | 118.9 mm |
| 2026-06-10 | 353.9 | 301.8 | 114.7 mm | 119.1 mm |
| 2026-06-11 | 367.3 | 309.0 | 114.7 mm | 119.2 mm |
| 2026-06-12 | 379.2 | 316.3 | 114.7 mm | 119.3 mm |
| 2026-06-13 | 389.7 | 323.7 | 114.7 mm | 119.3 mm |
| 2026-06-14 | 399.0 | 331.3 | 114.7 mm | 119.7 mm |
| 2026-06-15 | 407.9 | 338.6 | 114.8 mm | 120.0 mm |
| 2026-06-16 | 416.2 | 346.1 | 114.8 mm | 120.5 mm |
| 2026-06-17 | 424.9 | 353.9 | 114.9 mm | 120.9 mm |
| 2026-06-18 | 432.8 | 361.8 | 115.0 mm | 121.1 mm |
| 2026-06-19 | 440.1 | 369.9 | 115.3 mm | 121.1 mm |
| 2026-06-20 | 447.5 | 378.0 | 115.5 mm | 121.1 mm |
| 2026-06-21 | 455.8 | 386.2 | 115.5 mm | 121.2 mm |
| 2026-06-22 | 464.1 | 394.6 | 115.5 mm | 121.3 mm |
| 2026-06-23 | 472.3 | 402.7 | 115.6 mm | 121.4 mm |
| 2026-06-24 | 480.3 | 410.9 | 115.6 mm | 121.5 mm |
| 2026-06-25 | 487.9 | 419.4 | 115.6 mm | 122.4 mm |
| 2026-06-26 | 495.4 | 428.0 | 115.8 mm | 122.9 mm |
| 2026-06-27 | 502.9 | 436.8 | 116.1 mm | 123.5 mm |
| 2026-06-28 | 510.0 | 445.6 | 116.1 mm | 124.5 mm |
| 2026-06-29 | 519.0 | 454.3 | 116.1 mm | 125.5 mm |
| 2026-06-30 | 527.1 | 463.5 | 116.1 mm | 125.8 mm |
| 2026-07-01 | 535.5 | 472.7 | 116.1 mm | 125.8 mm |
| 2026-07-02 | 543.6 | 481.7 | 116.1 mm | 125.8 mm |
| 2026-07-03 | 552.6 | 490.8 | 116.1 mm | 125.9 mm |
| 2026-07-04 | 561.8 | 500.0 | 116.1 mm | 125.9 mm |
| 2026-07-05 | 570.2 | 508.9 | 116.1 mm | 125.9 mm |
| 2026-07-06 | 577.8 | 517.9 | 116.2 mm | 126.0 mm |
| 2026-07-07 | 584.9 | 527.0 | 116.4 mm | 126.0 mm |
| 2026-07-08 | 592.9 | 536.4 | 116.5 mm | 126.0 mm |
| 2026-07-09 | 602.3 | 545.8 | 116.6 mm | 126.1 mm |
| 2026-07-10 | 610.7 | 554.9 | 116.6 mm | 126.2 mm |
| 2026-07-11 | 619.2 | 564.1 | 116.6 mm | 126.3 mm |
| 2026-07-12 | 631.2 | 573.3 | 116.6 mm | 126.3 mm |
| 2026-07-13 | 643.9 | 582.9 | 116.6 mm | 126.4 mm |
| 2026-07-14 | 656.9 | 592.7 | 116.6 mm | 126.4 mm |
| 2026-07-15 | 669.2 | 602.3 | 116.6 mm | 126.4 mm |
| 2026-07-16 | 678.5 | 611.8 | 116.6 mm | 126.5 mm |
| 2026-07-17 | 686.5 | 621.0 | 116.6 mm | 126.6 mm |
| 2026-07-18 | 695.2 | 630.6 | 116.7 mm | 126.7 mm |
| 2026-07-19 | 704.0 | 640.0 | 116.7 mm | 126.8 mm |
| 2026-07-20 | 714.5 | 649.5 | 116.7 mm | 126.8 mm |
| 2026-07-21 | 728.4 | 659.0 | 116.9 mm | 126.9 mm |
| 2026-07-22 | 738.8 | 668.8 | 117.0 mm | 126.9 mm |
| 2026-07-23 | 748.4 | 678.8 | 117.0 mm | 126.9 mm |
| 2026-07-24 | 757.8 | 688.6 | 117.0 mm | 127.0 mm |
| 2026-07-25 | 767.1 | 698.6 | 117.0 mm | 127.0 mm |
| 2026-07-26 | 777.5 | 708.6 | 117.0 mm | 127.1 mm |
| 2026-07-27 | 787.7 | 718.7 | 117.0 mm | 127.1 mm |
| 2026-07-28 | 798.3 | 728.5 | 117.0 mm | 127.1 mm |
| 2026-07-29 | 808.9 | 738.0 | 117.1 mm | 127.2 mm |
| 2026-07-30 | 818.6 | 747.7 | 117.1 mm | 127.2 mm |
| 2026-07-31 | 828.8 | 757.3 | 117.1 mm | 127.3 mm |
| 2026-08-01 | 840.4 | 767.2 | 117.1 mm | 127.3 mm |
| 2026-08-02 | 852.6 | 777.0 | 117.1 mm | 127.4 mm |
| 2026-08-03 | 866.4 | 786.6 | 117.1 mm | 127.4 mm |
| 2026-08-04 | 878.6 | 795.8 | 117.1 mm | 127.5 mm |
| 2026-08-05 | 889.2 | 804.7 | 117.2 mm | 127.5 mm |
| 2026-08-06 | 899.4 | 813.9 | 117.4 mm | 127.6 mm |
| 2026-08-07 | 910.6 | 823.1 | 117.4 mm | 127.7 mm |
| 2026-08-08 | 922.3 | 832.7 | 117.4 mm | 127.7 mm |
| 2026-08-09 | 933.6 | 842.4 | 117.4 mm | 127.7 mm |
| 2026-08-10 | 944.1 | 852.2 | 117.4 mm | 127.8 mm |
| 2026-08-11 | 954.0 | 862.1 | 117.5 mm | 127.9 mm |
| 2026-08-12 | 962.8 | 872.0 | 117.5 mm | 127.9 mm |
| 2026-08-13 | 971.0 | 882.0 | 117.7 mm | 127.9 mm |
| 2026-08-14 | 979.1 | 891.9 | 118.0 mm | 128.0 mm |
| 2026-08-15 | 987.3 | 901.8 | 118.2 mm | 128.0 mm |
| 2026-08-16 | 996.8 | 911.9 | 118.2 mm | 128.1 mm |
| 2026-08-17 | 1007.8 | 921.5 | 118.2 mm | 128.2 mm |
| 2026-08-18 | 1018.8 | 931.1 | 118.3 mm | 128.2 mm |
| 2026-08-19 | 1029.8 | 940.3 | 118.3 mm | 128.4 mm |
| 2026-08-20 | 1038.9 | 949.3 | 118.4 mm | 129.1 mm |
| 2026-08-21 | 1048.3 | 958.3 | 118.6 mm | 129.2 mm |
| 2026-08-22 | 1058.2 | 967.8 | 118.6 mm | 129.3 mm |
| 2026-08-23 | 1070.1 | 977.4 | 118.6 mm | 129.3 mm |
Forecast outlook
ECMWF IFS 0.25° via Herbie · run Aug 30, 2026 at 00:00 UTC
10-day totals compared with the 1991–2020 combined regional record
- GDD accumulation
- 71 GDDvs 95 GDD average
- Total rainfall
- 17.3 mmvs 0.7 mm average
No unusually hot or wet period stands out in the short-range forecast.
Sun8/30
27°Cavg 27°C
11°Cavg 11°C
+9 GDD
0.0 mm
Mon8/31
23°Cavg 28°C
11°Cavg 11°C
+6 GDD
0.0 mm
Tue9/1
18°Cavg 28°C
11°Cavg 11°C
+4 GDD
1.1 mm
Wed9/2
19°Cavg 29°C
11°Cavg 11°C
+4 GDD
1.5 mm
Thu9/3
20°Cavg 28°C
11°Cavg 11°C
+5 GDD
0.0 mm
Fri9/4
22°Cavg 27°C
12°Cavg 11°C
+6 GDD
0.0 mm
Sat9/5
23°Cavg 28°C
10°Cavg 11°C
+7 GDD
0.0 mm
Sun9/6
28°Cavg 29°C
10°Cavg 11°C
+9 GDD
0.0 mm
Mon9/7
26°Cavg 28°C
11°Cavg 11°C
+10 GDD
0.0 mm
Tue9/8
24°Cavg 28°C
16°Cavg 11°C
+10 GDD
14.8 mm
Data and methods
Show data sources and model assumptions
Current temperature, dew point, humidity, and wind use geographically weighted NWS station observations. The 24-hour rain total and 10-day outlook use the 00 UTC deterministic ECMWF IFS 0.25° public forecast retrieved directly with Herbie. Historical temperature and rain combine qualifying GHCN-D stations with ERA5 by geographic area; a missing station day uses the nearest ERA5 value for that station's area. Climate comparisons use 1991–2020.
Forecast comparisons use the 1991–2020 combined regional daily record. Daily high and low averages use the matching date; rainfall and GDD sum the same calendar dates as the forecast period.
This service is based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF). Weather & Vines subsets, converts, and regionally weights the forecast fields. ECMWF data are published under CC BY 4.0. ECMWF accepts no liability for errors, omissions, availability, loss, or damage arising from their use.
Climate projections use NASA NEX-GDDP-CMIP6 v2.0, accessed August 23, 2026, with 25 models. Weather & Vines subsets and aggregates the source fields. Source files and derived projection data are under CC BY-SA 4.0; the full roster and limitations are listed in the climate atlas methods.
The Sonoma & Mendocino model uses a April 1–October 31 growing season, base 10°C GDD, and an operational hot-day marker of 32°C.
- Sonoma County Winegrowers: 2025 harvest began mid-August, on schedule
- Sonoma Valley: harvest runs end of August through early October (Sonoma Valley sub-AVA)
- WMO climate normals guidance
The historical series uses 2 ERA5 locations, 17 temperature stations, and 18 rain stations. Interpretation confidence: high. Geometry confidence: reviewed-approximate. Rules: sonoma-county-catalog-v1-2026-07.