WEATHER · CLIMATE NORMALS · 1991–2020
Denver Climate — Averages by Month
What the weather in Denver, USaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | -1.8 °C | 24.3 mm |
| February | -0.6 °C | 26.1 mm |
| March | 4.0 °C | 50.5 mm |
| April | 7.9 °C | 73.1 mm |
| May | 13.1 °C | 86.3 mm · wettest |
| June | 18.9 °C | 55.7 mm |
| July | 22.2 °C · warmest | 43.4 mm |
| August | 21.0 °C | 41.8 mm |
| September | 16.8 °C | 38.2 mm |
| October | 9.6 °C | 41.7 mm |
| November | 2.7 °C | 33.0 mm |
| December | -2.0 °C · coldest | 23.4 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Denver — centred at 39.75°N, 105.00°W. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.