WEATHER · CLIMATE NORMALS · 1991–2020
Tucson Climate — Averages by Month
What the weather in Tucson, 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 | 10.9 °C | 30.8 mm |
| February | 12.6 °C | 29.0 mm |
| March | 16.2 °C | 18.8 mm |
| April | 20.1 °C | 6.6 mm |
| May | 25.0 °C | 3.3 mm |
| June | 30.2 °C | 5.1 mm |
| July | 30.7 °C · warmest | 35.7 mm |
| August | 29.9 °C | 36.9 mm · wettest |
| September | 27.8 °C | 26.7 mm |
| October | 22.1 °C | 15.5 mm |
| November | 15.6 °C | 17.2 mm |
| December | 10.5 °C · coldest | 32.0 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 Tucson — centred at 32.25°N, 111.00°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.