August is one of the warmer months of the year in San Tan Valley, with average highs near 37.4°C and lows around 24.2°C (mean 30.8°C). It is a relatively wet time of year, averaging 56 mm of rainfall and 42% relative humidity across the period.
August is one of the warmer months of the year in San Tan Valley. Across 45 years of records, the warmest August in San Tan Valley was 2020 — when the month averaged 34.3°C — while the coldest was 1990 at 27.6°C. Typical August days reach 37.4°C with nights near 24.2°C. The long-term trend is warming, about 0.5°C per decade.
August is a relatively wet time of year in San Tan Valley, averaging 56 mm of rainfall. The wettest August on record was 1990 with 108 mm, while the driest was 2020 at 15 mm.
Relative humidity in San Tan Valley during August averages 42%. The most humid August was 1984 at 56%, and the least humid was 2009 at 27%.
August receives about 6.8 kWh/m²/day of solar energy in San Tan Valley. The sunniest August was 2009 at 7.3 kWh/m²/day, and the cloudiest was 1988 at 6.1.
Average wind speed in San Tan Valley during August is 1.8 m/s. The windiest Augusts were 1996, 2020 and 2023, among others at 2.1 m/s, while the calmest was 2007 at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 30.0°C | 30.6°C | 30.5°C | 31.3°C | 32.2°C | +2.2°C |
| Avg High | 36.5°C | 37.2°C | 37.1°C | 37.8°C | 39.0°C | +2.5°C |
| Avg Low | 23.4°C | 23.9°C | 24.0°C | 24.7°C | 25.5°C | +2.1°C |
| Avg Rain | 66 mm | 69 mm | 50 mm | 42 mm | 52 mm | -14 mm |
August temperatures in San Tan Valley have risen by about 1.6°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 16.5°C (1990) to a record high of 44.8°C (2025).
Rainfall in August is a relatively wet time of year, averaging 56 mm, with a wettest year of 108 mm.
A good time to visit San Tan Valley
August is a good time to visit San Tan Valley, with days averaging 37.4°C and nights around 24.2°C (mean 30.8°C, warmer than San Tan Valley's yearly average) and moderate rainfall. October and May are marginally more temperate, but August still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 39.1°C | 31.9°C | 24.6°C | 44.8°C | 22.2°C | 83 mm | 38% | 1.7 m/s | 7 |
| 2024 | 39.7°C | 32.9°C | 26.0°C | 44.3°C | 22.8°C | 34 mm | 36% | 1.7 m/s | 6.8 |
| 2023 | 40.4°C | 33.6°C | 26.8°C | 44.4°C | 23.1°C | 19 mm | 32% | 2.1 m/s | 6.7 |
| 2022 | 36.6°C | 30.4°C | 24.3°C | 41.1°C | 22.6°C | 81 mm | 50% | 1.6 m/s | 6.5 |
| 2021 | 36.6°C | 30.3°C | 24.1°C | 42.8°C | 20.5°C | 78 mm | 48% | 1.7 m/s | 6.7 |
| 2020 🔥 | 41.4°C | 34.3°C | 27.2°C | 44.7°C | 24.4°C | 15 mm | 28% | 2.1 m/s | 7 |
| 2019 | 39.4°C | 32.6°C | 25.8°C | 44.2°C | 23.4°C | 17 mm | 32% | 1.9 m/s | 7.1 |
| 2018 | 37.4°C | 31.3°C | 25.2°C | 43.9°C | 21.8°C | 45 mm | 41% | 1.6 m/s | 6.9 |
| 2017 | 38.1°C | 31.2°C | 24.4°C | 41.4°C | 20.0°C | 26 mm | 37% | 2 m/s | 7.1 |
| 2016 | 36.2°C | 30.0°C | 23.7°C | 40.6°C | 20.8°C | 45 mm | 44% | 1.8 m/s | 6.8 |
| 2015 | 38.8°C | 32.2°C | 25.6°C | 44.0°C | 23.0°C | 43 mm | 38% | 2 m/s | 6.9 |
| 2014 | 35.7°C | 29.3°C | 23.0°C | 40.0°C | 19.6°C | 68 mm | 46% | 1.7 m/s | 6.8 |
| 2013 | 37.6°C | 31.0°C | 24.4°C | 43.3°C | 20.7°C | 36 mm | 38% | 1.9 m/s | 6.2 |
| 2012 | 38.2°C | 31.6°C | 24.9°C | 44.4°C | 22.1°C | 50 mm | 41% | 1.7 m/s | 6.8 |
| 2011 | 39.8°C | 32.9°C | 26.0°C | 43.1°C | 23.6°C | 38 mm | 35% | 1.9 m/s | 7 |
| 2010 | 37.2°C | 30.8°C | 24.4°C | 41.8°C | 19.4°C | 49 mm | 44% | 1.9 m/s | 6.9 |
| 2009 | 39.2°C | 31.7°C | 24.2°C | 42.4°C | 19.6°C | 16 mm | 27% | 1.9 m/s | 7.3 |
| 2008 | 35.3°C | 29.6°C | 24.0°C | 41.7°C | 21.4°C | 86 mm | 49% | 1.7 m/s | 6.9 |
| 2007 | 36.9°C | 30.9°C | 24.9°C | 42.4°C | 20.8°C | 57 mm | 48% | 1.5 m/s | 6.7 |
| 2006 | 34.5°C | 28.9°C | 23.3°C | 38.8°C | 19.0°C | 49 mm | 51% | 1.6 m/s | 6.7 |
| 2005 | 35.7°C | 29.5°C | 23.3°C | 41.5°C | 20.6°C | 70 mm | 49% | 1.7 m/s | 6.7 |
| 2004 | 37.4°C | 30.3°C | 23.2°C | 42.0°C | 19.6°C | 39 mm | 35% | 1.9 m/s | 6.8 |
| 2003 | 37.8°C | 31.3°C | 24.9°C | 44.2°C | 21.7°C | 40 mm | 41% | 2 m/s | 6.8 |
| 2002 | 38.8°C | 31.5°C | 24.2°C | 42.3°C | 21.1°C | 29 mm | 32% | 1.9 m/s | 7 |
| 2001 | 37.6°C | 30.7°C | 23.8°C | 42.5°C | 21.4°C | 55 mm | 42% | 1.6 m/s | 6.8 |
| 2000 | 37.3°C | 30.7°C | 24.0°C | 42.2°C | 18.7°C | 63 mm | 43% | 1.8 m/s | 6.5 |
| 1999 | 37.8°C | 30.6°C | 23.4°C | 42.5°C | 20.2°C | 61 mm | 40% | 1.8 m/s | 6.6 |
| 1998 | 38.3°C | 31.6°C | 24.8°C | 43.1°C | 22.7°C | 48 mm | 40% | 1.9 m/s | 6.9 |
| 1997 | 37.3°C | 31.0°C | 24.6°C | 41.9°C | 21.9°C | 56 mm | 44% | 1.8 m/s | 6.6 |
| 1996 | 38.0°C | 31.1°C | 24.3°C | 42.4°C | 20.5°C | 47 mm | 40% | 2.1 m/s | 7.2 |
| 1995 | 38.5°C | 31.9°C | 25.4°C | 44.3°C | 22.1°C | 76 mm | 43% | 1.8 m/s | 6.9 |
| 1994 | 38.9°C | 32.1°C | 25.4°C | 43.5°C | 23.3°C | 44 mm | 40% | 1.9 m/s | 6.9 |
| 1993 | 36.6°C | 30.1°C | 23.7°C | 43.2°C | 20.4°C | 99 mm | 44% | 1.8 m/s | 6.5 |
| 1992 | 35.8°C | 29.4°C | 23.0°C | 42.1°C | 17.1°C | 103 mm | 49% | 1.8 m/s | 6.7 |
| 1991 | 36.6°C | 30.1°C | 23.6°C | 40.9°C | 21.5°C | 49 mm | 40% | 1.8 m/s | 6.5 |
| 1990 ❄️ 🌧️ | 34.2°C | 27.6°C | 20.9°C | 40.1°C | 16.5°C | 108 mm | 50% | 2.1 m/s | 6.8 |
| 1989 | 36.4°C | 29.6°C | 22.8°C | 40.1°C | 18.2°C | 41 mm | 42% | 2 m/s | 7.2 |
| 1988 | 36.0°C | 29.7°C | 23.3°C | 39.7°C | 21.2°C | 94 mm | 50% | 2 m/s | 6.1 |
| 1987 | 35.6°C | 28.9°C | 22.2°C | 39.9°C | 18.2°C | 53 mm | 44% | 1.7 m/s | 6.9 |
| 1986 | 36.7°C | 30.5°C | 24.3°C | 42.1°C | 21.8°C | 79 mm | 47% | 1.6 m/s | 6.6 |
| 1985 | 38.0°C | 31.0°C | 23.9°C | 43.1°C | 20.5°C | 40 mm | 38% | 1.7 m/s | 6.9 |
| 1984 | 34.3°C | 28.5°C | 22.6°C | 40.4°C | 19.8°C | 93 mm | 56% | 1.6 m/s | 6.2 |
| 1983 | 36.5°C | 29.8°C | 23.1°C | 40.9°C | 18.8°C | 88 mm | 50% | 1.6 m/s | — |
| 1982 | 36.5°C | 30.4°C | 24.2°C | 40.8°C | 21.4°C | 72 mm | 48% | 1.7 m/s | — |
| 1981 | 38.5°C | 31.4°C | 24.4°C | 42.6°C | 21.1°C | 35 mm | 37% | 2 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 37.4°C with lows near 24.2°C (mean 30.8°C), based on 45 years of NASA POWER data.
August averages 56 mm of rainfall in San Tan Valley, a relatively wet time of year. The wettest on record was 108 mm in 1990.
The hottest August reached 44.8°C in 2025. The coldest dipped to 16.5°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.6°C. Daytime highs moved from 36.8°C to 38.5°C and overnight lows from 23.6°C to 25.2°C over the same span.
August is one of the warmer months of the year in San Tan Valley and a relatively wet time of year, so plan for around 37.4°C daytime highs and 24.2°C at night.
Not quite — August is the 11th coolest month in San Tan Valley, averaging 30.8°C.
For August in San Tan Valley, pack light, breathable clothing and sun protection, with typical highs of 37.4°C and lows of 24.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 42% — relatively dry.
Average wind speed in August is 1.8 m/s. The windiest August on record averaged 2.1 m/s (1990).
The wettest August on record was 1990 with 108 mm. On average, August sees 56 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in San Tan Valley behaves each August, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for August specifically, along with year-by-year records and how the month has changed over the decades.
