August is one of the warmer months of the year in Casa Grande, with average highs near 39.8°C and lows around 26.2°C (mean 33°C). It is a relatively wet time of year, averaging 41 mm of rainfall and 38% relative humidity across the period.
August is one of the warmer months of the year in Casa Grande. Across 45 years of records, the warmest August in Casa Grande was 2020 — when the month averaged 36.1°C — while the coldest was 1990 at 29.7°C. Typical August days reach 39.8°C with nights near 26.2°C. The long-term trend is warming, about 0.5°C per decade.
August is a relatively wet time of year in Casa Grande, averaging 41 mm of rainfall. The wettest August on record was 1990 with 83 mm, while the driest was 2002 at 10 mm.
Relative humidity in Casa Grande during August averages 38%. The most humid August was 1984 at 52%, and the least humid was 2009 at 26%.
August receives about 6.7 kWh/m²/day of solar energy in Casa Grande. The sunniest August was 2009 at 7.2 kWh/m²/day, and the cloudiest were 1988 and 2013 at 6.2.
Average wind speed in Casa Grande during August is 1.7 m/s. The windiest Augusts were 1989, 1990 and 1996 at 2.1 m/s, while the calmest were 2006, 2007 and 2022 at 1.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 32.2°C | 32.7°C | 32.7°C | 33.4°C | 34.2°C | +2°C |
| Avg High | 38.8°C | 39.5°C | 39.4°C | 40.3°C | 41.2°C | +2.4°C |
| Avg Low | 25.6°C | 25.9°C | 26.0°C | 26.6°C | 27.2°C | +1.6°C |
| Avg Rain | 48 mm | 49 mm | 36 mm | 32 mm | 43 mm | -5 mm |
August temperatures in Casa Grande have risen by about 1.4°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 17.4°C (1990) to a record high of 47.3°C (2025).
Rainfall in August is a relatively wet time of year, averaging 41 mm, with a wettest year of 83 mm.
A quieter season to visit Casa Grande
If your dates are flexible, the more temperate months of April and October tend to be the most comfortable for visiting Casa Grande. That said, August — with days averaging 39.8°C and nights around 26.2°C (mean 33°C) and moderate rainfall (41 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 41.8°C | 34.0°C | 26.3°C | 47.3°C | 24.0°C | 56 mm | 32% | 1.7 m/s | 7 |
| 2024 | 41.9°C | 34.8°C | 27.7°C | 45.9°C | 24.2°C | 31 mm | 32% | 1.6 m/s | 6.7 |
| 2023 | 42.4°C | 35.3°C | 28.3°C | 46.7°C | 24.4°C | 18 mm | 29% | 1.9 m/s | 6.6 |
| 2022 | 38.9°C | 32.5°C | 26.2°C | 42.9°C | 24.2°C | 67 mm | 47% | 1.4 m/s | 6.5 |
| 2021 | 38.9°C | 32.3°C | 25.8°C | 44.7°C | 21.6°C | 72 mm | 45% | 1.5 m/s | 6.8 |
| 2020 🔥 | 43.5°C | 36.1°C | 28.6°C | 46.3°C | 25.6°C | 16 mm | 27% | 1.9 m/s | 7 |
| 2019 | 42.1°C | 34.7°C | 27.4°C | 46.6°C | 24.6°C | 21 mm | 29% | 1.8 m/s | 7 |
| 2018 | 39.8°C | 33.2°C | 26.6°C | 46.1°C | 23.2°C | 44 mm | 39% | 1.6 m/s | 6.7 |
| 2017 | 40.3°C | 33.2°C | 26.0°C | 43.5°C | 21.7°C | 24 mm | 33% | 1.7 m/s | 7.1 |
| 2016 | 38.9°C | 32.4°C | 25.9°C | 43.1°C | 22.1°C | 37 mm | 38% | 1.6 m/s | 6.8 |
| 2015 | 40.9°C | 34.1°C | 27.4°C | 45.8°C | 24.4°C | 34 mm | 35% | 1.8 m/s | 6.8 |
| 2014 | 38.6°C | 31.8°C | 25.1°C | 42.9°C | 21.5°C | 42 mm | 40% | 1.5 m/s | 6.6 |
| 2013 | 39.8°C | 33.1°C | 26.4°C | 44.9°C | 23.1°C | 24 mm | 33% | 1.7 m/s | 6.2 |
| 2012 | 40.4°C | 33.7°C | 27.0°C | 46.2°C | 24.4°C | 41 mm | 38% | 1.5 m/s | 6.7 |
| 2011 | 42.7°C | 35.5°C | 28.2°C | 46.2°C | 25.1°C | 12 mm | 28% | 1.7 m/s | 6.6 |
| 2010 | 39.4°C | 32.7°C | 26.0°C | 44.0°C | 19.6°C | 37 mm | 39% | 1.8 m/s | 6.7 |
| 2009 | 41.2°C | 33.6°C | 26.0°C | 44.7°C | 21.1°C | 18 mm | 26% | 1.7 m/s | 7.2 |
| 2008 | 38.0°C | 32.0°C | 26.0°C | 44.3°C | 22.8°C | 66 mm | 43% | 1.6 m/s | 6.7 |
| 2007 | 39.2°C | 33.0°C | 26.8°C | 43.7°C | 22.7°C | 34 mm | 42% | 1.4 m/s | 6.6 |
| 2006 | 37.6°C | 31.4°C | 25.3°C | 41.1°C | 22.0°C | 40 mm | 44% | 1.4 m/s | 6.6 |
| 2005 | 38.0°C | 31.8°C | 25.5°C | 44.0°C | 22.0°C | 55 mm | 45% | 1.5 m/s | 6.6 |
| 2004 | 40.0°C | 32.8°C | 25.5°C | 44.1°C | 21.1°C | 25 mm | 31% | 1.7 m/s | 6.8 |
| 2003 | 39.3°C | 32.8°C | 26.3°C | 46.2°C | 23.0°C | 38 mm | 40% | 1.9 m/s | 6.7 |
| 2002 | 41.6°C | 33.8°C | 25.9°C | 44.7°C | 22.5°C | 10 mm | 27% | 2 m/s | 6.9 |
| 2001 | 39.7°C | 32.8°C | 25.9°C | 44.8°C | 22.9°C | 36 mm | 39% | 1.5 m/s | 6.7 |
| 2000 | 39.5°C | 33.0°C | 26.5°C | 45.2°C | 20.7°C | 35 mm | 37% | 1.7 m/s | 6.5 |
| 1999 | 40.2°C | 32.9°C | 25.7°C | 44.6°C | 21.9°C | 39 mm | 33% | 1.6 m/s | 6.7 |
| 1998 | 40.6°C | 33.9°C | 27.1°C | 44.7°C | 23.8°C | 35 mm | 37% | 1.8 m/s | 6.8 |
| 1997 | 39.1°C | 32.7°C | 26.2°C | 43.6°C | 23.8°C | 58 mm | 43% | 1.6 m/s | 6.4 |
| 1996 | 40.3°C | 33.4°C | 26.4°C | 44.2°C | 21.5°C | 30 mm | 37% | 2.1 m/s | 7 |
| 1995 | 40.6°C | 33.9°C | 27.2°C | 46.0°C | 23.9°C | 54 mm | 40% | 1.7 m/s | 6.5 |
| 1994 | 41.3°C | 34.5°C | 27.7°C | 45.7°C | 26.0°C | 23 mm | 35% | 1.9 m/s | 6.7 |
| 1993 | 39.1°C | 32.4°C | 25.7°C | 45.4°C | 21.5°C | 73 mm | 38% | 1.8 m/s | 6.4 |
| 1992 | 37.7°C | 31.3°C | 24.9°C | 44.3°C | 18.3°C | 71 mm | 45% | 1.7 m/s | 6.7 |
| 1991 | 39.3°C | 32.5°C | 25.7°C | 43.5°C | 23.2°C | 22 mm | 33% | 1.8 m/s | 6.5 |
| 1990 ❄️ 🌧️ | 36.9°C | 29.7°C | 22.5°C | 41.7°C | 17.4°C | 83 mm | 45% | 2.1 m/s | 6.9 |
| 1989 | 39.0°C | 31.9°C | 24.7°C | 42.6°C | 19.2°C | 22 mm | 36% | 2.1 m/s | 6.8 |
| 1988 | 38.6°C | 32.0°C | 25.5°C | 44.2°C | 22.7°C | 65 mm | 44% | 1.8 m/s | 6.2 |
| 1987 | 38.2°C | 31.3°C | 24.4°C | 42.3°C | 19.5°C | 31 mm | 38% | 1.7 m/s | 6.9 |
| 1986 | 38.6°C | 32.5°C | 26.3°C | 43.3°C | 23.1°C | 56 mm | 43% | 1.7 m/s | 6.6 |
| 1985 | 41.0°C | 33.6°C | 26.3°C | 45.7°C | 22.7°C | 25 mm | 31% | 1.8 m/s | 6.8 |
| 1984 | 36.6°C | 30.6°C | 24.7°C | 43.0°C | 21.8°C | 69 mm | 52% | 1.5 m/s | 6.3 |
| 1983 | 37.8°C | 31.3°C | 24.9°C | 43.0°C | 20.1°C | 80 mm | 48% | 1.5 m/s | — |
| 1982 | 38.6°C | 32.4°C | 26.2°C | 43.9°C | 22.9°C | 57 mm | 44% | 1.6 m/s | — |
| 1981 | 41.1°C | 34.1°C | 27.1°C | 45.1°C | 24.1°C | 25 mm | 33% | 1.9 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 39.8°C with lows near 26.2°C (mean 33°C), based on 45 years of NASA POWER data.
August averages 41 mm of rainfall in Casa Grande, a relatively wet time of year. The wettest on record was 83 mm in 1990.
The hottest August reached 47.3°C in 2025. The coldest dipped to 17.4°C in 1990.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.4°C. Daytime highs moved from 39°C to 40.8°C and overnight lows from 25.8°C to 26.9°C over the same span.
August is one of the warmer months of the year in Casa Grande and a relatively wet time of year, so plan for around 39.8°C daytime highs and 26.2°C at night.
Not quite — August is the 11th coolest month in Casa Grande, averaging 33°C.
For August in Casa Grande, pack light, breathable clothing and sun protection, with typical highs of 39.8°C and lows of 26.2°C.
Relative humidity in August averages 38% — relatively dry.
Average wind speed in August is 1.7 m/s. The windiest August on record averaged 2.1 m/s (1989).
The wettest August on record was 1990 with 83 mm. On average, August sees 41 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 Casa Grande 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.
