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Forecast confidence: High · models disagree by 3°F

San Tan Valley weather

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Mostly clear,much the same tomorrow

NWS, the American and the European model agree on a high near 77° in San Tan Valley today. Tomorrow: clear, around 79°, with a 1% chance of rain.

77°56°
79°54°
82°57°
83°61°
85°61°
84°64°
Todaymodels agreeTomorrowmodels agreeMondaymodels agreeTuesdaymodels agreeWednesdaysplit ±7°Thursdaysplit ±6°
NWSNational Blend (NBM)
78°
Mostly clear
Today 78°·Low 58°·Rain 1%
AmericanNOAA GFS
78°
Partly cloudy
Today 78°·Low 52°·Rain 1%
EuropeanECMWF
75°
Mostly clear
Today 75°·Low 58°·Rain 6%
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San Tan Valley weather alerts and warnings

active National Weather Service watches, warnings and advisories

Checking the National Weather Service for active alerts covering San Tan Valley…

San Tan Valley weather in numbers

measured normals and 10 years of recorded weather

San Tan Valley swings 64°F across the year, from 103°F highs in July to 39°F lows in December, and August is usually the wettest month in a year that brings about 10 in of precipitation. Over 10 years of recorded weather it averages 242 days a year at 77°F or above, 186 of them at 86°F or above, 2 frost nights, and rain on 39 days.

Warmest month
July
103°F average high
Coldest month
December
39°F average low
Wettest month
August
10 in a year
Comfortable
4 months
January, February, March and November
Residents
81,000
share this forecast
Most accurate here
European
95/100 CheckWeather Score
Warm days
242 days
a year at 77°F or above
Frost nights
2 nights
a year below 32°F
Rain days
39 days
a year with 0.04 in or more

Day counts are from the ERA5 reanalysis for San Tan Valley’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.

The weather map: all three models at once

NWS, American, European side by side around San Tan Valley and nearby towns.Live rain radar →
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San Tan Valley hourly forecast: next 14 hours

consensus of the three models

Rain in the next 24 hours, model by model

each model's own hourly precipitation, side by side

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San Tan Valley 10-day forecast, out to 14 days

where the models agree, and where they split
Today
Mostly clear
77° 56°
models agree
Tomorrow
Clear
79° 54°
models agree
Mon
Clear
82° 57°
models agree
Tue
Clear
83° 61°
models agree
Wed
Partly cloudy
85° 61°
±7°
Thu
Light drizzle
84° 64°
±6°
Fri
Light drizzle
80° 65°
±8°
Sat
Drizzle
72° 63°
models agree
Sun
Drizzle
74° 62°
±10°
Mon
Drizzle
75° 61°
±17°
Tue
Cloudy
79° 62°
±10°
Wed
Drizzle
78° 62°
±10°
Thu
Cloudy
72° 60°
±9°

San Tan Valley, Arizona (AZ) is at its warmest in Jul (average highs near 103°F) and coldest in Dec (lows around 39°F), with roughly 10 in of precipitation across the year. Below, compare what NWS, American, European forecast for San Tan Valley right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

San Tan Valley climate by month

average daytime high and overnight low across a typical year (1991-2020)
Jan
63°
43°
Feb
66°
45°
Mar
73°
50°
Apr
83°
54°
May
92°
65°
Jun
101°
74°
Jul
103°
79°
Aug
100°
78°
Sep
97°
72°
Oct
86°
59°
Nov
73°
49°
Dec
64°
39°

Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.

How San Tan Valley's weather has changed since 1995

30 years of daily data, 1995-2024, shown as change
+1.8°F

Around San Tan Valley, 2015-2024 averaged 1.8°F warmer than 1995-2004. 8 of the 10 warmest years since 1995 fall in the last ten, and the warmest was 2017.

1995: −1.1°F vs the 30-year average1996: −0.2°F vs the 30-year average1997: −0.8°F vs the 30-year average1998: −2.9°F vs the 30-year average1999: −0.4°F vs the 30-year average2000: −0.2°F vs the 30-year average2001: −0.4°F vs the 30-year average2002: +0.1°F vs the 30-year average2003: +0.3°F vs the 30-year average2004: −0.9°F vs the 30-year average2005: −0.4°F vs the 30-year average2006: −0.8°F vs the 30-year average2007: −0.2°F vs the 30-year average2008: −1.8°F vs the 30-year average2009: −0.4°F vs the 30-year average2010: −1.5°F vs the 30-year average2011: −0.8°F vs the 30-year average2012: +0.7°F vs the 30-year average2013: −0.8°F vs the 30-year average2014: +0.9°F vs the 30-year average2015: +0.5°F vs the 30-year average2016: +1.6°F vs the 30-year average2017: +2.5°F vs the 30-year average2018: +1.4°F vs the 30-year average2019: −0.2°F vs the 30-year average2020: +1.9°F vs the 30-year average2021: +1.0°F vs the 30-year average2022: +0.1°F vs the 30-year average2023: +1.0°F vs the 30-year average2024: +1.9°F vs the 30-year average
1995each stripe is one year2024
cooler than averagearound averagewarmer than average

Days above 95°F

4 more days a year

2015-2024 against 1995-2004. Within the normal year-to-year swing

1995: −17 vs the 30-year average1996: +3 vs the 30-year average1997: +10 vs the 30-year average1998: −17 vs the 30-year average1999: −11 vs the 30-year average2000: +21 vs the 30-year average2001: +14 vs the 30-year average2002: +5 vs the 30-year average2003: +19 vs the 30-year average2004: −1 vs the 30-year average2005: −10 vs the 30-year average2006: −24 vs the 30-year average2007: −9 vs the 30-year average2008: −25 vs the 30-year average2009: −0 vs the 30-year average2010: −7 vs the 30-year average2011: +13 vs the 30-year average2012: −3 vs the 30-year average2013: −4 vs the 30-year average2014: −9 vs the 30-year average2015: −9 vs the 30-year average2016: −11 vs the 30-year average2017: +2 vs the 30-year average2018: +9 vs the 30-year average2019: −3 vs the 30-year average2020: +34 vs the 30-year average2021: −9 vs the 30-year average2022: −0 vs the 30-year average2023: +24 vs the 30-year average2024: +28 vs the 30-year average

Frost nights

2 fewer nights a year

2015-2024 against 1995-2004, below 32°F. Within the normal year-to-year swing

1995: −7 vs the 30-year average1996: −3 vs the 30-year average1997: +6 vs the 30-year average1998: +4 vs the 30-year average1999: −4 vs the 30-year average2000: −3 vs the 30-year average2001: +4 vs the 30-year average2002: −1 vs the 30-year average2003: −3 vs the 30-year average2004: +3 vs the 30-year average2005: −3 vs the 30-year average2006: +1 vs the 30-year average2007: +9 vs the 30-year average2008: +7 vs the 30-year average2009: −1 vs the 30-year average2010: −2 vs the 30-year average2011: +4 vs the 30-year average2012: −7 vs the 30-year average2013: +12 vs the 30-year average2014: −7 vs the 30-year average2015: +3 vs the 30-year average2016: −5 vs the 30-year average2017: −6 vs the 30-year average2018: −4 vs the 30-year average2019: +3 vs the 30-year average2020: −5 vs the 30-year average2021: −5 vs the 30-year average2022: +0 vs the 30-year average2023: −2 vs the 30-year average2024: −2 vs the 30-year average

Average wind

−4%

2015-2024 against 1995-2004

1995: −1% vs the 30-year average1996: +5% vs the 30-year average1997: +2% vs the 30-year average1998: +2% vs the 30-year average1999: +5% vs the 30-year average2000: −1% vs the 30-year average2001: −1% vs the 30-year average2002: +2% vs the 30-year average2003: +2% vs the 30-year average2004: +2% vs the 30-year average2005: −4% vs the 30-year average2006: −1% vs the 30-year average2007: −4% vs the 30-year average2008: +5% vs the 30-year average2009: +2% vs the 30-year average2010: +2% vs the 30-year average2011: +2% vs the 30-year average2012: −4% vs the 30-year average2013: +2% vs the 30-year average2014: −4% vs the 30-year average2015: −4% vs the 30-year average2016: +2% vs the 30-year average2017: −4% vs the 30-year average2018: −4% vs the 30-year average2019: −1% vs the 30-year average2020: −1% vs the 30-year average2021: −4% vs the 30-year average2022: −1% vs the 30-year average2023: +2% vs the 30-year average2024: −7% vs the 30-year average

Bars: each year against the area's 30-year average. Dashed lines: the average of the first and the last ten years.

See the numbers year by year
YearTemp vs averageDays >95°F vs avgFrost nights vs avgWind vs avg
1995−1.1°F−17−7−1%
1996−0.2°F+3−3+5%
1997−0.8°F+10+6+2%
1998−2.9°F−17+4+2%
1999−0.4°F−11−4+5%
2000−0.2°F+21−3−1%
2001−0.4°F+14+4−1%
2002+0.1°F+5−1+2%
2003+0.3°F+19−3+2%
2004−0.9°F−1+3+2%
2005−0.4°F−10−3−4%
2006−0.8°F−24+1−1%
2007−0.2°F−9+9−4%
2008−1.8°F−25+7+5%
2009−0.4°F−0−1+2%
2010−1.5°F−7−2+2%
2011−0.8°F+13+4+2%
2012+0.7°F−3−7−4%
2013−0.8°F−4+12+2%
2014+0.9°F−9−7−4%
2015+0.5°F−9+3−4%
2016+1.6°F−11−5+2%
2017+2.5°F+2−6−4%
2018+1.4°F+9−4−4%
2019−0.2°F−3+3−1%
2020+1.9°F+34−5−1%
2021+1.0°F−9−5−4%
2022+0.1°F−0+0−1%
2023+1.0°F+24−2+2%
2024+1.9°F+28−2−7%

Source: NASA POWER daily data from the MERRA-2 reanalysis, 1995-2024. Each value describes a grid square of about 50 km around San Tan Valley, not a weather station, and a square that takes in sea or a large lake runs milder than the city itself. That is why this section shows change against the square's own 30-year average rather than counts you could compare with a local station. Rain and snow are left out because their long-term record in this dataset is not consistent over time. "Within the normal year-to-year swing" means the change is smaller than the usual differences between single years.

Which forecast is most accurate in San Tan Valley?

CheckWeather Score, graded against the weather that actually happened
ProviderCheckWeather-scoreTempWindRainRun by
European logo
European ★ Best
95
/100rank #1
98±0.2°F92±2.4 mph9597% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
78
/100rank #2
86±1.4°F94±1.8 mph5877% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

What do you think of the forecasts?

your vote counts

The accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.

NWSNational Blend (NBM)
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AmericanNOAA GFS
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EuropeanECMWF
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One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±3°75° to 78°±5%1% to 6% chance
Tomorrow±2°78° to 80°±1%0% to 1% chance
Mon±3°80° to 83°models agree0% to 0% chance
Tue±3°81° to 84°models agree0% to 0% chance
Wed±7°81° to 88°models agree0% to 0% chance

The models often agree on temperature and still split on rain, and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.

Sunrise and sunset in San Tan Valley

today, local time
Sunrise
06:37
Sunset
17:42
Daylight
11h 5m

Common questions

What's the weather in San Tan Valley today?
Saturday, October 24: NWS, the American and the European model agree on a high near 77° in San Tan Valley today. Tomorrow: clear, around 79°, with a 1% chance of rain. The forecast on this page refreshes live.
Will it rain in San Tan Valley today or tomorrow?
Rain looks unlikely in San Tan Valley on Sunday, October 25: no model gives more than 1% (NWS 1%, American 1%, European 0%). On Saturday, October 24 the highest chance of rain from any model is 6%. The hourly strip and the model-by-model rain panel above update live.
Which forecast is most accurate for San Tan Valley?
Over the last 30 days, the European model has been the most accurate for San Tan Valley (CheckWeather Score 95/100), ahead of the American at 78. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in San Tan Valley?
July is typically the warmest month in San Tan Valley, with average highs around 103°F.
How cold does San Tan Valley get?
The coldest month in San Tan Valley is December, when overnight lows average about 39°F.
How much rain does San Tan Valley get?
San Tan Valley sees roughly 10 in of precipitation a year, with August usually the wettest month.
Is San Tan Valley getting warmer?
Yes. In NASA's reanalysis for the area around San Tan Valley, 2015-2024 averaged 1.8°F warmer than 1995-2004.

Nearby

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