San Tan Valley, AZ climate
San Tan Valley has warm winters and scorching summers, with very little rain. A typical July afternoon reaches 105°, a January night drops to 40°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in San Tan Valley feels like
Winter
Spring
Summer
Fall
San Tan Valley weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 67° | 40° | 1.1" | 0 | 3 | 0 | 50° – 59° |
| February | 70° | 43° | 1.2" | 0 | 4 | 0 | 51° – 62° |
| March | 77° | 47° | 1.0" | 0 | 3 | 0 | 55° – 69° |
| April | 85° | 53° | 0.3" | 0 | 1 | 0 | 63° – 74° |
| May | 94° | 61° | 0.2" | 0 | 1 | 0 | 72° – 83° |
| June | 103° | 70° | 0.1" | 0 | 0 | 0 | 81° – 90° |
| July | 105° | 78° | 1.0" | 0 | 2 | 0 | 88° – 94° |
| August | 103° | 77° | 1.2" | 0 | 3 | 0 | 87° – 94° |
| September | 99° | 71° | 0.8" | 0 | 1 | 0 | 81° – 87° |
| October | 88° | 59° | 0.6" | 0 | 1 | 0 | 70° – 78° |
| November | 76° | 47° | 0.6" | 0 | 1 | 0 | 53° – 67° |
| December | 66° | 39° | 1.0" | 0 | 2 | 0 | 50° – 56° |
| Year | 86° | 57° | 9.1" | 0.0" | 24 | 0 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in San Tan Valley
San Tan Valley gets 9 inches of rain and melted snow a year. August is the wettest month and June the driest. Rain or snow falls on about 24 days a year.
About 315 frost-free days a year
In half of years the last 32° night comes by February 1 and the first one by December 11. That leaves about 315 frost-free days for gardens, longer than 96% of U.S. towns.
Heating and cooling a home in San Tan Valley
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In San Tan Valley, 27% of that work is heating and 73% is cooling, so air conditioning is the bigger bill.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
San Tan Valley and its neighbors
San Tan Valley borders 2 towns with climate data. January nights across them vary by 0.9°. Florence has the coldest January nights (40°) and Queen Creek the hottest July afternoons (105°). San Tan Valley’s January low is 40° and its July high 105°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How San Tan Valley compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in San Tan Valley averaged 2.0° warmer than the 1900s. The biggest change is in March (+2.8°). The shift is larger than in 94% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at San Tan Valley’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 53° to 67°. July is the most reliable, staying within 6°.
Common questions about San Tan Valley’s climate
What is the coldest month in San Tan Valley?
December, with a typical high of 66° and a low of 39°.
What is the hottest month in San Tan Valley?
July, with a typical high of 105° and a low of 78°. About 165 days a year reach 90°.
How much snow does San Tan Valley get?
Almost none. A normal year brings 0.0 inches.
When is the first frost in San Tan Valley?
In half of years the first 32° night comes by December 11, and the last spring frost by February 1.
What is the rainiest month in San Tan Valley?
August, with 1.2 inches of rain and melted snow. The year totals 9 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for San Tan Valley itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Florence, AZ (14 mi, snow) and Chandler Heights, AZ (7 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.