July is one of the warmer months of the year in Decatur, with average highs near 29°C and lows around 18.6°C (mean 23.8°C). It is a relatively wet time of year, averaging 103 mm of rainfall and 76% relative humidity across the period.
July is one of the warmer months of the year in Decatur. Across 45 years of records, the warmest July in Decatur was 2012 — when the month averaged 29.9°C — while the coldest was 2009 at 20.7°C. Typical July days reach 29°C with nights near 18.6°C. The long-term trend is warming, about 0.2°C per decade.
July is a relatively wet time of year in Decatur, averaging 103 mm of rainfall. The wettest July on record was 1992 with 271 mm, while the driest was 2012 at 21 mm.
Relative humidity in Decatur during July averages 76%. The most humid July was 1993 at 86%, and the least humid was 2012 at 47%.
July receives about 6.2 kWh/m²/day of solar energy in Decatur. The sunniest July was 1997 at 6.8 kWh/m²/day, and the cloudiest was 1992 at 5.2.
Average wind speed in Decatur during July is 2.2 m/s. The windiest July was 1990 at 2.6 m/s, while the calmest were 1998, 2011 and 2020 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 24.0°C | 23.2°C | 23.6°C | 24.2°C | 24.5°C | +0.5°C |
| Avg High | 29.2°C | 28.3°C | 29.0°C | 29.3°C | 29.6°C | +0.4°C |
| Avg Low | 18.7°C | 18.1°C | 18.2°C | 19.2°C | 19.3°C | +0.6°C |
| Avg Rain | 104 mm | 103 mm | 110 mm | 84 mm | 125 mm | +21 mm |
July temperatures in Decatur have risen by about 1.6°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 8.8°C (1983) to a record high of 42°C (2012).
Rainfall in July is a relatively wet time of year, averaging 103 mm, with a wettest year of 271 mm.
One of the best times to visit Decatur
July is one of the best times to visit Decatur. Expect days averaging 29°C and nights around 18.6°C (mean 23.8°C) — warmer than Decatur's yearly average — with higher rainfall (103 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 | 30.7°C | 26.0°C | 21.3°C | 33.1°C | 17.2°C | 117 mm | 77% | 2 m/s | 6.1 |
| 2024 | 28.8°C | 23.6°C | 18.4°C | 32.1°C | 11.0°C | 190 mm | 75% | 2.1 m/s | 6 |
| 2023 | 31.0°C | 25.0°C | 19.0°C | 38.5°C | 15.3°C | 97 mm | 68% | 2 m/s | 6.5 |
| 2022 | 30.3°C | 24.8°C | 19.3°C | 35.4°C | 14.9°C | 96 mm | 72% | 2.2 m/s | 6 |
| 2021 | 27.9°C | 23.0°C | 18.1°C | 31.1°C | 12.1°C | 102 mm | 81% | 2 m/s | 5.7 |
| 2020 | 29.2°C | 24.4°C | 19.6°C | 31.7°C | 15.5°C | 146 mm | 80% | 1.9 m/s | 6.5 |
| 2019 | 29.0°C | 24.3°C | 19.6°C | 32.0°C | 13.2°C | 63 mm | 82% | 2.1 m/s | 6.6 |
| 2018 | 28.0°C | 23.0°C | 18.1°C | 31.6°C | 13.1°C | 111 mm | 79% | 2.2 m/s | 6.5 |
| 2017 | 30.1°C | 24.6°C | 19.1°C | 34.2°C | 13.5°C | 86 mm | 74% | 2.1 m/s | 6.7 |
| 2016 | 28.1°C | 23.9°C | 19.7°C | 30.4°C | 11.9°C | 153 mm | 84% | 2 m/s | 6 |
| 2015 | 27.6°C | 22.9°C | 18.3°C | 31.6°C | 12.8°C | 83 mm | 83% | 2.1 m/s | 5.6 |
| 2014 | 26.2°C | 20.8°C | 15.5°C | 30.3°C | 11.3°C | 70 mm | 75% | 2.4 m/s | 6.4 |
| 2013 | 26.8°C | 22.0°C | 17.2°C | 31.6°C | 9.4°C | 71 mm | 81% | 2.2 m/s | 5.9 |
| 2012 🔥 | 37.1°C | 29.9°C | 22.7°C | 42.0°C | 17.8°C | 21 mm | 47% | 2.3 m/s | 6.5 |
| 2011 | 30.5°C | 25.9°C | 21.3°C | 34.2°C | 16.5°C | 55 mm | 81% | 1.9 m/s | 6.5 |
| 2010 | 29.2°C | 24.6°C | 20.0°C | 31.7°C | 12.5°C | 128 mm | 82% | 2.1 m/s | 6.5 |
| 2009 ❄️ | 25.4°C | 20.7°C | 16.0°C | 28.4°C | 11.6°C | 113 mm | 81% | 2.1 m/s | 5.6 |
| 2008 | 27.7°C | 22.8°C | 17.9°C | 30.8°C | 12.7°C | 190 mm | 83% | 2.2 m/s | 6.3 |
| 2007 | 28.0°C | 22.4°C | 16.7°C | 32.3°C | 11.3°C | 71 mm | 73% | 2.2 m/s | 6.7 |
| 2006 | 31.6°C | 25.7°C | 19.9°C | 36.6°C | 13.0°C | 115 mm | 70% | 2.4 m/s | 6.3 |
| 2005 | 32.4°C | 25.8°C | 19.3°C | 39.0°C | 13.9°C | 82 mm | 63% | 2.3 m/s | 6.4 |
| 2004 | 27.3°C | 22.6°C | 17.9°C | 31.7°C | 12.6°C | 108 mm | 80% | 2.2 m/s | 5.6 |
| 2003 | 29.2°C | 23.6°C | 18.1°C | 35.3°C | 13.3°C | 154 mm | 73% | 2.5 m/s | 6.7 |
| 2002 | 29.5°C | 24.6°C | 19.8°C | 32.9°C | 13.4°C | 96 mm | 77% | 2.1 m/s | 6.5 |
| 2001 | 30.9°C | 24.8°C | 18.8°C | 35.1°C | 9.8°C | 71 mm | 68% | 2.1 m/s | 6.2 |
| 2000 | 28.2°C | 22.9°C | 17.5°C | 31.4°C | 11.5°C | 96 mm | 75% | 2.1 m/s | 5.9 |
| 1999 | 30.6°C | 25.2°C | 19.8°C | 37.1°C | 11.1°C | 72 mm | 74% | 2.4 m/s | 6.6 |
| 1998 | 27.7°C | 23.1°C | 18.4°C | 32.0°C | 12.7°C | 79 mm | 81% | 1.9 m/s | 5.9 |
| 1997 | 31.0°C | 24.5°C | 18.1°C | 38.2°C | 11.1°C | 42 mm | 67% | 2.4 m/s | 6.8 |
| 1996 | 27.2°C | 21.5°C | 15.8°C | 32.4°C | 10.4°C | 81 mm | 74% | 2.4 m/s | 6.2 |
| 1995 | 28.0°C | 23.5°C | 18.9°C | 32.0°C | 11.4°C | 69 mm | 81% | 2 m/s | 6.5 |
| 1994 | 27.2°C | 22.4°C | 17.7°C | 31.3°C | 12.4°C | 68 mm | 81% | 2.1 m/s | 6.1 |
| 1993 | 28.3°C | 24.2°C | 20.1°C | 31.4°C | 15.8°C | 179 mm | 86% | 2.4 m/s | 5.4 |
| 1992 🌧️ | 26.8°C | 22.0°C | 17.3°C | 31.2°C | 13.2°C | 271 mm | 83% | 2.4 m/s | 5.2 |
| 1991 | 29.5°C | 23.8°C | 18.2°C | 34.6°C | 13.1°C | 66 mm | 71% | 2.2 m/s | 6.5 |
| 1990 | 26.8°C | 21.9°C | 16.9°C | 32.1°C | 12.7°C | 109 mm | 81% | 2.6 m/s | 6 |
| 1989 | 29.9°C | 24.4°C | 18.9°C | 35.1°C | 15.1°C | 84 mm | 72% | 2.3 m/s | 5.9 |
| 1988 | 34.5°C | 27.2°C | 19.9°C | 40.5°C | 11.4°C | 46 mm | 51% | 2 m/s | 6.1 |
| 1987 | 30.8°C | 25.5°C | 20.3°C | 35.1°C | 12.7°C | 101 mm | 74% | 2.2 m/s | 5.7 |
| 1986 | 29.1°C | 24.4°C | 19.8°C | 33.6°C | 14.2°C | 150 mm | 81% | 2.3 m/s | 6.2 |
| 1985 | 27.7°C | 22.3°C | 16.9°C | 30.8°C | 11.2°C | 84 mm | 75% | 2.3 m/s | 5.9 |
| 1984 | 26.7°C | 21.3°C | 15.9°C | 31.1°C | 10.6°C | 85 mm | 77% | 2.2 m/s | 5.9 |
| 1983 | 29.0°C | 24.3°C | 19.5°C | 33.3°C | 8.8°C | 36 mm | 79% | 2.3 m/s | — |
| 1982 | 27.8°C | 23.3°C | 18.8°C | 30.8°C | 13.1°C | 134 mm | 82% | 2.3 m/s | — |
| 1981 | 27.7°C | 23.1°C | 18.5°C | 32.0°C | 12.1°C | 218 mm | 84% | 2.1 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 29°C with lows near 18.6°C (mean 23.8°C), based on 45 years of NASA POWER data.
July averages 103 mm of rainfall in Decatur, a relatively wet time of year. The wettest on record was 271 mm in 1992.
The hottest July reached 42°C in 2012. The coldest dipped to 8.8°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 1.6°C. Daytime highs moved from 27.8°C to 29.7°C and overnight lows from 17.9°C to 19.2°C over the same span.
July is one of the warmer months of the year in Decatur and a relatively wet time of year, so plan for around 29°C daytime highs and 18.6°C at night.
Not quite — July is the 12th coolest month in Decatur, averaging 23.8°C.
For July in Decatur, pack light layers you can adjust through the day, with typical highs of 29°C and lows of 18.6°C. Bring an umbrella or light rain jacket too.
Relative humidity in July averages 76% — quite humid.
Average wind speed in July is 2.2 m/s. The windiest July on record averaged 2.6 m/s (1990).
The wettest July on record was 1992 with 271 mm. On average, July sees 103 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 July, 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 July specifically, along with year-by-year records and how the month has changed over the decades.
