Arizona's desert summers are extreme: NOAA's 1991–2020 normals for Phoenix Sky Harbor give highs of 104.2–106.5°F from June to August, while winter highs are 66.2–70.8°F. Flagstaff is far cooler (a July high of 82.0°F and 20.9 inches of January snow). Choose by region; we have no verified dataset for crowds or prices.
Month-by-month climate table
| Month | Normal high | Normal low | Normal precipitation | Verified schedule notes |
|---|---|---|---|---|
| January | 67.6°F | 46.0°F | 0.87 in | — |
| February | 70.8°F | 49.0°F | 0.87 in | — |
| March | 78.1°F | 54.5°F | 0.83 in | Hermit Road closed to private vehicles from Mar 1 |
| April | 85.5°F | 60.8°F | 0.22 in | — |
| May | 94.5°F | 69.5°F | 0.13 in | — |
| June | 104.2°F | 78.6°F | 0.02 in | — |
| July | 106.5°F | 84.5°F | 0.91 in | — |
| August | 105.1°F | 83.6°F | 0.93 in | — |
| September | 100.4°F | 78.1°F | 0.57 in | Grand Canyon fall shuttle routes begin Sep 12 |
| October | 89.2°F | 65.6°F | 0.56 in | — |
| November | 76.5°F | 53.7°F | 0.57 in | Hermit Road closure and fall shuttles end Nov 30 |
| December | 66.2°F | 45.3°F | 0.74 in | — |
Source: NOAA NCEI U.S. Climate Normals 1991–2020, Phoenix Sky Harbor International Airport (USW00023183), retrieved October 17, 2026. Normals are 30-year averages; actual weather varies. Schedule notes are from the National Park Service.
Other regions at a glance
| Station | January high / low | July high / low | January snow | Wettest summer month |
|---|---|---|---|---|
| Phoenix | 67.6°F / 46.0°F | 106.5°F / 84.5°F | not reported | August (0.93 in) |
| Tucson | 66.5°F / 40.8°F | 100.2°F / 76.3°F | 0 in | July (2.21 in) |
| Flagstaff | 43.4°F / 17.6°F | 82.0°F / 51.4°F | 20.9 in | August (3.04 in) |
How to choose your month
- Phoenix and Tucson: November–April (Phoenix highs 66.2–85.5°F).
- Flagstaff and the Grand Canyon rim: late spring to early fall; Flagstaff winters are snowy.
- Hottest: June–August in the desert cities (Phoenix lows stay above 78°F).
Limits of this guide
Normals describe typical conditions, not forecasts, and we have no verified dataset for Grand Canyon rim weather, crowds or prices by month, so this page makes no such claims. Use the National Weather Service for forecasts.