Updated October 2026
Casa Grande Ruins National Monument Weather by Month
Casa Grande Ruins National Monument is warmest in July, when the nearest NOAA climate station averages a high of 107°F and a low of 77°F, and coldest in December, with an average high of 67°F and an average low of 36°F. August is the wettest month, with about 1.2 inches of precipitation.
These figures are NOAA's 1991–2020 climate normals, the 30-year average for each calendar month, from the nearest long-record weather station, 0.3 miles from the park's reference point. A single station cannot describe a whole park: temperatures elsewhere in Casa Grande Ruins National Monument can differ from these, particularly with elevation.
Warmest month
Jul
107°F avg high
Coldest month
Dec
36°F avg low
Wettest month
Aug
1.2 in avg
Longest days
Jun
14.2 h of daylight
Average weather at Casa Grande Ruins by month
| Month | Avg high | Avg low | Precipitation | Daylight |
|---|---|---|---|---|
| January | 68°F | 37°F | 1.0 in | 10.0 h |
| February | 71°F | 40°F | 1.0 in | 10.8 h |
| March | 78°F | 45°F | 0.9 in | 11.8 h |
| April | 86°F | 51°F | 0.3 in | 12.8 h |
| May | 95°F | 59°F | 0.2 in | 13.7 h |
| June | 105°F | 68°F | 0.1 in | 14.2 h |
| July | 107°F | 77°F | 1.1 in | 14.0 h |
| August | 105°F | 77°F | 1.2 in | 13.2 h |
| September | 101°F | 70°F | 0.7 in | 12.2 h |
| October | 91°F | 56°F | 0.5 in | 11.2 h |
| November | 78°F | 44°F | 0.5 in | 10.3 h |
| December | 67°F | 36°F | 0.8 in | 9.8 h |
| Year total | 8.3 in |
NOAA 1991–2020 climate normals from station USC00021314, 0.3 miles from the park's reference point. The station's snowfall normal is zero in all twelve months. Daylight is the monthly average, computed from the park's latitude. Each month links to how crowded Casa Grande Ruins is at that time of year.
Casa Grande Ruins weather by season
Winter: December to February
Average highs climb from 67°F in December to 71°F in February, with average lows between 36°F and 40°F. Together the three months average 2.8 inches of precipitation, about 34% of the yearly total and more than in any other season. Daylight is at its shortest, about 9.8 hours in December.
Spring: March to May
Average highs climb from 78°F in March to 95°F in May, with average lows between 45°F and 59°F. The average high is 90°F or hotter in May. Together the three months average 1.4 inches of precipitation, about 17% of the yearly total and less than in any other season. Daylight lengthens from about 11.8 hours in March to 13.7 in May.
Summer: June to August
Average highs hold near 106°F in all three months, with average lows between 68°F and 77°F. The average high is 100°F or hotter in all three months. Together the three months average 2.4 inches of precipitation, about 29% of the yearly total. Daylight is at its longest, about 14.2 hours in June.
Fall: September to November
Average highs fall from 101°F in September to 78°F in November, with average lows between 44°F and 70°F. The average high is 100°F or hotter in September. Together the three months average 1.7 inches of precipitation, about 20% of the yearly total. Daylight shortens from about 12.2 hours in September to 10.3 in November.
What the National Park Service says about the weather
Summer daytime temperatures frequently exceed 100 degrees F. Winter temperatures range from the 60's to the 80's F. Spring and fall are warm and dry, with highs in the 80's and 90's F. During summer months, be prepared for hot temperatures. Protective clothing, hats, sunscreen and personal water containers are highly recommended. BE AWARE: Walls of dirt and debris, usually miles wide and thousands of feet high, are pushed across dry desert terrain by high winds, causing dust to engulf highways.
Weather description courtesy of the National Park Service — official park site.
Today's forecast for Casa Grande Ruins
Averages describe a typical month, not this week. For current conditions and the seven-day outlook, the National Weather Service issues a forecast for the park's reference point at 33.00°N, 111.53°W. It covers that one spot, so other elevations in the park can differ from it, as they do from the averages above.
National Weather Service forecast for Casa Grande Ruins National Monument →
Weather and crowds together
July, the warmest month, sees about 0.5× the visitors of the park's average month. March is the busiest month of the year and August the quietest. To see those crowds set against the weather for all twelve months, read the best time to visit Casa Grande Ruins National Monument. For hotels, cabins and rentals close to the park, see where to stay near Casa Grande Ruins.
Where to stay near Casa Grande Ruins
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Frequently Asked Questions
July is the warmest month at Casa Grande Ruins National Monument, with an average high of 107°F and an average low of 77°F. That is the 1991–2020 average at the nearest long-record NOAA station, 0.3 miles from the park's reference point. Temperatures inside the park can differ, particularly with elevation.
December is the coldest month at Casa Grande Ruins National Monument, with an average low of 36°F and an average high of 67°F, based on NOAA 1991–2020 climate normals.
August is the wettest month, with about 1.2 inches of precipitation. June is the driest, at about 0.1 inches. The station records about 8.3 inches of precipitation in an average year.
The nearest long-record NOAA station, 0.3 miles from the park's reference point, shows no measurable snowfall in any month of its 1991–2020 normals.
Weather at nearby parks
51 mi away · warmest in July (104°F)
71 mi away · warmest in June (101°F)
102 mi away · warmest in July (104°F)
103 mi away · warmest in June (95°F)
113 mi away · warmest in July (101°F)
126 mi away · warmest in July (101°F)
Keep exploring
Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (station USC00021314), daylight computed from latitude, weather description from the National Park Service, crowd levels from National Park Service Visitor Use Statistics (1979–2025). Updated 2026-10-11. Lodging results are provided by Stay22; WhenToVisitParks may earn a commission from bookings, at no extra cost to you.