August is one of the warmer months of the year in Decatur, with average highs near 29.1°C and lows around 17.6°C (mean 23.4°C). It is about average for rainfall, averaging 88 mm of rainfall and 72% relative humidity across the period.
August is one of the warmer months of the year in Decatur. Across 45 years of records, the warmest August in Decatur was 1988 — when the month averaged 27°C — while the coldest was 1992 at 19.6°C. Typical August days reach 29.1°C with nights near 17.6°C. The long-term trend is warming, about 0.2°C per decade.
August is about average for rainfall in Decatur, averaging 88 mm of rainfall. The wettest August on record was 1981 with 203 mm, while the driest was 2011 at 18 mm.
Relative humidity in Decatur during August averages 72%. The most humid August was 1993 at 85%, and the least humid was 1988 at 53%.
August receives about 5.6 kWh/m²/day of solar energy in Decatur. The sunniest August was 2010 at 6.4 kWh/m²/day, and the cloudiest was 1985 at 4.7.
Average wind speed in Decatur during August is 2.1 m/s. The windiest August was 2000 at 2.6 m/s, while the calmest was 1995 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 23.4°C | 22.7°C | 23.7°C | 23.5°C | 23.8°C | +0.4°C |
| Avg High | 29.5°C | 28.2°C | 29.4°C | 29.0°C | 29.6°C | +0.1°C |
| Avg Low | 17.3°C | 17.1°C | 18.0°C | 18.0°C | 18.0°C | +0.7°C |
| Avg Rain | 89 mm | 92 mm | 97 mm | 77 mm | 79 mm | -10 mm |
August temperatures in Decatur have risen by about 1.1°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 6.9°C (1986) to a record high of 40.5°C (1988).
Rainfall in August is about average for rainfall, averaging 88 mm, with a wettest year of 203 mm.
One of the best times to visit Decatur
August is one of the best times to visit Decatur. Expect days averaging 29.1°C and nights around 17.6°C (mean 23.4°C) — warmer than Decatur's yearly average — with higher rainfall (88 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 30.5°C | 24.1°C | 17.8°C | 35.6°C | 10.9°C | 35 mm | 64% | 2.2 m/s | 6.1 |
| 2024 | 29.8°C | 23.7°C | 17.6°C | 36.6°C | 9.9°C | 78 mm | 67% | 2.2 m/s | 5.8 |
| 2023 | 30.7°C | 24.2°C | 17.7°C | 36.1°C | 10.3°C | 97 mm | 68% | 2.2 m/s | 5.4 |
| 2022 | 30.0°C | 24.1°C | 18.2°C | 33.4°C | 13.3°C | 135 mm | 71% | 2.2 m/s | 5.7 |
| 2021 | 28.6°C | 24.0°C | 19.4°C | 32.7°C | 13.3°C | 92 mm | 81% | 2 m/s | 5.8 |
| 2020 | 28.0°C | 22.5°C | 17.0°C | 33.7°C | 12.3°C | 37 mm | 74% | 2 m/s | 6.1 |
| 2019 | 28.1°C | 23.0°C | 18.0°C | 31.8°C | 12.4°C | 79 mm | 78% | 2.2 m/s | 5.5 |
| 2018 | 28.5°C | 23.6°C | 18.7°C | 32.2°C | 14.2°C | 89 mm | 79% | 2.4 m/s | 5.6 |
| 2017 | 29.3°C | 22.8°C | 16.3°C | 35.2°C | 12.7°C | 54 mm | 63% | 2.1 m/s | 5.8 |
| 2016 | 28.4°C | 24.1°C | 19.7°C | 33.2°C | 14.4°C | 136 mm | 82% | 2 m/s | 5.2 |
| 2015 | 27.1°C | 21.9°C | 16.6°C | 31.4°C | 10.8°C | 56 mm | 77% | 2.1 m/s | 5.8 |
| 2014 | 28.4°C | 23.5°C | 18.6°C | 33.9°C | 11.8°C | 127 mm | 78% | 2.1 m/s | 4.8 |
| 2013 | 28.2°C | 22.6°C | 17.1°C | 35.4°C | 10.6°C | 29 mm | 76% | 1.8 m/s | 5.7 |
| 2012 | 31.8°C | 24.6°C | 17.4°C | 38.1°C | 12.1°C | 96 mm | 55% | 2.1 m/s | 5.9 |
| 2011 | 31.0°C | 24.6°C | 18.3°C | 36.6°C | 14.7°C | 18 mm | 68% | 2.2 m/s | 6.1 |
| 2010 | 28.9°C | 24.0°C | 19.1°C | 33.0°C | 12.6°C | 82 mm | 80% | 2 m/s | 6.4 |
| 2009 | 25.9°C | 21.2°C | 16.4°C | 30.8°C | 8.6°C | 111 mm | 83% | 2.4 m/s | 5.5 |
| 2008 | 26.4°C | 21.2°C | 16.1°C | 29.7°C | 11.3°C | 46 mm | 80% | 2 m/s | 5.9 |
| 2007 | 32.5°C | 26.5°C | 20.6°C | 37.2°C | 13.3°C | 60 mm | 68% | 2.3 m/s | 5.7 |
| 2006 | 29.6°C | 24.2°C | 18.7°C | 36.8°C | 14.1°C | 106 mm | 71% | 2.4 m/s | 5.2 |
| 2005 | 32.0°C | 25.8°C | 19.7°C | 36.4°C | 13.9°C | 78 mm | 64% | 2.1 m/s | 5.3 |
| 2004 | 27.2°C | 21.3°C | 15.3°C | 32.1°C | 9.0°C | 117 mm | 72% | 2.5 m/s | 5.5 |
| 2003 | 30.9°C | 24.6°C | 18.4°C | 38.2°C | 15.1°C | 118 mm | 67% | 2.2 m/s | 5.6 |
| 2002 | 27.9°C | 23.1°C | 18.2°C | 31.7°C | 12.6°C | 132 mm | 78% | 2.3 m/s | 5.4 |
| 2001 | 31.2°C | 24.8°C | 18.4°C | 36.4°C | 12.7°C | 109 mm | 65% | 2.1 m/s | 5.6 |
| 2000 | 30.5°C | 24.1°C | 17.8°C | 35.9°C | 11.9°C | 97 mm | 69% | 2.6 m/s | 5.4 |
| 1999 | 28.7°C | 22.2°C | 15.8°C | 34.1°C | 11.6°C | 111 mm | 65% | 2.2 m/s | 5.8 |
| 1998 | 27.5°C | 22.7°C | 17.9°C | 31.6°C | 13.9°C | 120 mm | 82% | 1.9 m/s | 5.5 |
| 1997 | 29.0°C | 23.1°C | 17.2°C | 36.0°C | 10.9°C | 111 mm | 70% | 2.3 m/s | 5 |
| 1996 | 30.0°C | 23.8°C | 17.5°C | 35.4°C | 14.1°C | 55 mm | 67% | 2 m/s | 5.8 |
| 1995 | 29.9°C | 25.3°C | 20.7°C | 32.8°C | 14.7°C | 96 mm | 80% | 1.6 m/s | 5.7 |
| 1994 | 27.5°C | 21.3°C | 15.1°C | 32.8°C | 8.9°C | 91 mm | 74% | 2.2 m/s | 5.4 |
| 1993 | 27.4°C | 23.1°C | 18.8°C | 31.5°C | 13.5°C | 122 mm | 85% | 1.9 m/s | 5.2 |
| 1992 ❄️ | 25.2°C | 19.6°C | 14.0°C | 29.6°C | 9.6°C | 23 mm | 77% | 2.1 m/s | 5.7 |
| 1991 | 29.7°C | 23.7°C | 17.8°C | 37.0°C | 12.7°C | 111 mm | 67% | 2.1 m/s | 5.3 |
| 1990 | 27.5°C | 22.1°C | 16.6°C | 33.8°C | 9.9°C | 84 mm | 77% | 1.8 m/s | 5.5 |
| 1989 | 30.5°C | 24.3°C | 18.2°C | 35.4°C | 11.9°C | 105 mm | 66% | 2.2 m/s | 5.4 |
| 1988 🔥 | 34.0°C | 27.0°C | 20.1°C | 40.5°C | 10.4°C | 45 mm | 53% | 2.4 m/s | 5.7 |
| 1987 | 30.8°C | 24.4°C | 17.9°C | 37.9°C | 11.8°C | 89 mm | 66% | 2.5 m/s | 5.4 |
| 1986 | 27.1°C | 20.7°C | 14.2°C | 34.0°C | 6.9°C | 36 mm | 67% | 2.1 m/s | 5.6 |
| 1985 | 26.1°C | 20.8°C | 15.5°C | 30.3°C | 9.1°C | 139 mm | 80% | 2.1 m/s | 4.7 |
| 1984 | 30.8°C | 24.1°C | 17.4°C | 38.3°C | 10.1°C | 25 mm | 65% | 2.1 m/s | 5.4 |
| 1983 | 33.5°C | 26.7°C | 19.9°C | 39.2°C | 13.1°C | 59 mm | 62% | 2 m/s | — |
| 1982 | 26.8°C | 21.3°C | 15.8°C | 31.7°C | 9.3°C | 100 mm | 77% | 2.1 m/s | — |
| 1981 🌧️ | 26.2°C | 21.4°C | 16.6°C | 29.9°C | 10.6°C | 203 mm | 83% | 2.2 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 29.1°C with lows near 17.6°C (mean 23.4°C), based on 45 years of NASA POWER data.
August averages 88 mm of rainfall in Decatur, about average for rainfall. The wettest on record was 203 mm in 1981.
The hottest August reached 40.5°C in 1988. The coldest dipped to 6.9°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.1°C. Daytime highs moved from 28.7°C to 29.9°C and overnight lows from 17°C to 18.1°C over the same span.
August is one of the warmer months of the year in Decatur and about average for rainfall, so plan for around 29.1°C daytime highs and 17.6°C at night.
Not quite — August is the 11th coolest month in Decatur, averaging 23.4°C.
For August in Decatur, pack light layers you can adjust through the day, with typical highs of 29.1°C and lows of 17.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 72% — moderately humid.
Average wind speed in August is 2.1 m/s. The windiest August on record averaged 2.6 m/s (2000).
The wettest August on record was 1981 with 203 mm. On average, August sees 88 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 Decatur 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.
