Temperature climate layer

Mean Annual Minimum Temperature Map

See the mean of each year’s lowest available hourly ERA5-Land 2 m air temperature during 2011–2025. This cold-extreme metric helps compare the typical severity of annual cold extremes between locations.

Explore Interactive Map General methodology
Source
ERA5-Land
Climate period
2011–2025 average
Representation
°C / °F

What this map shows

For each grid cell, the map shows the arithmetic mean of 15 annual minimum temperatures—one lowest available hourly 2 m air temperature from each complete calendar year between 2011 and 2025.

It does not show the average temperature of winter, the average daily minimum, or the single coldest temperature in the full period. Those are different metrics with different practical meanings.

How it is calculated

MetriClima converts valid hourly ERA5-Land t2m (2 m air temperature) samples from kelvin to degrees Celsius, identifies the lowest available hourly sample in each complete UTC calendar year, and then calculates the arithmetic mean of those 15 annual minima for each grid cell. Daily minimum temperature is not calculated first.

The same mean annual minimum temperature values are also used to assign the MetriClima USDA Hardiness Zones layer; the hardiness layer applies its own 2.78 °C zone classification to this statistic.

Data source

MetriClima processes ERA5-Land surface data on the 0.1° latitude–longitude download grid. The physical spacing of this geographic grid varies with latitude. ERA5-Land is a land-surface reanalysis dataset providing consistent hourly climate variables.

This layer uses the ERA5-Land t2m variable, which represents air temperature 2 m above the land surface.

Provider
Copernicus Climate Change Service (C3S), produced by ECMWF

Climate period and representation

2011–2025 average

Average of the annual minimum temperature from 15 complete calendar years. Individual annual minima within the period may have been substantially colder or warmer.

°C / °F

Values are continuous temperatures displayed in unit-specific bands. Lower values indicate more severe recurring annual cold.

How to interpret the map

Use this layer to compare the characteristic severity of annual cold extremes between locations. A value of −15 °C means the annual minimum averaged about −15 °C across the period; it does not mean every year reached exactly that temperature.

For the coldest modeled event anywhere in 2011–2025, use Extreme Minimum Temperature instead. For the corresponding plant-hardiness classification, use USDA Hardiness Zones.

Applications

  • Perennial plant and crop cold-hardiness screening
  • Comparing typical annual cold extremes between locations
  • Providing climatic context for winterization and freeze-resilience planning
  • Understanding the temperature basis of USDA Hardiness Zones

Limitations

  • A 15-year mean may smooth rare but damaging cold outbreaks.
  • Cold-air drainage, sheltered gardens, urban warming, and elevation changes within a grid cell can produce local minima that differ from the map.
  • Modeled 2 m temperature is an estimate and should not replace site observations for high-consequence engineering or crop decisions.
  • Hourly sampling does not capture temperature changes between hourly ERA5-Land samples.

Explore this map by country

Open Mean Annual Minimum Temperature for a country to start the same interactive map focused on that geography.

Africa (54)
Asia (50)
Australia (14)
Europe (47)
North America (24)
South America (12)