The weather in each growing season is partially, but not completely, responsible for the characteristics of the final wine.

The numbers come from weather models and reanalysis data sampled at a small set of locations within each region.

They are best read as a regional view of the season. Conditions can differ from one vineyard, slope, or elevation to the next.

Some regions use one representative location, and multiple configured locations can resolve to the same grid cell. Locations that share a grid cell are one weather-grid sample, not independent observations.

The ERA5 historical record and IFS forecasts use 0.25-degree latitude/longitude data. Where eligible stations are available, NOAA’s Global Historical Climatology Network also contributes point observations.

Climate projections display a weighted ensemble of possible outcomes from 25 models in NASA NEX-GDDP-CMIP6 v2.0, using CMIP6 runs under three emissions pathways.

The ensemble spread shows how the included models differ and is a useful view of model uncertainty, but it does not include every possible outcome or every source of uncertainty. These are projections, not forecasts or probabilities.

Weather shapes ripening, disease pressure, water demand, and harvest timing. It is only one part of the finished wine. Grape variety, vineyard site, soil, farming, irrigation, crop level, picking date, sorting, and winemaking all matter.

Similar years are matched by regional weather patterns. A close weather match does not necessarily mean that the wines will taste alike.

Grape pages show where a variety appears in this atlas and make it easy to compare climates.

Some map outlines come from official geographic sources. Others are approximate areas included to make browsing easier. Dashed outlines are approximate and should not be read as legal appellation boundaries.

Weather data can arrive late or contain gaps. Pages show their latest update time and keep the last successful result visible when a refresh fails. Figures that are still being calculated are marked as not ready rather than filled with estimates.