Climate averages 1991–2020
Springfield (Illinois), United States weather
in August.
A hot, moderately wet month: the 2nd warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Springfield (Illinois), United States: daytime highs average 28.6°C and nights cool to about 19.5°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 78 mm of rain on roughly 9 days, which makes August a moderately wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 44 min on an average August day.
The nearest other city in this atlas is Decatur (59 km away). In August its highs average 28.3°C, about as warm as Springfield (Illinois), United States, with 77 mm of rain.
Among the 498 cities listed in the United States, Springfield (Illinois), United States ranks joint 299th of 498 for the warmest August highs and joint 254th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Springfield (Illinois), United States is 1.3°C cooler than that mean.
From August to September, average highs fall by 3.4°C to 25.2°C, and monthly rainfall rises from 78 mm to 80 mm.
The annual picture
August in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Springfield (Illinois), United States climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.9°C-6.2°C | -6.2°C | 61 | 8.0 | 9.710 h |
| February | 4.7°C-4.6°C | -4.6°C | 57 | 7.6 | 10.711 h |
| March | 10.9°C0.8°C | 0.8°C | 80 | 10.0 | 11.912 h |
| April | 17.4°C6.9°C | 6.9°C | 116 | 11.9 | 13.213 h |
| May | 22.7°C13.0°C | 13.0°C | 117 | 13.3 | 14.314 h |
| June | 27.4°C18.0°C | 18.0°C | 110 | 11.4 | 14.915 h |
| July | 29.1°C20.2°C | 20.2°C | 91 | 10.1 | 14.715 h |
| August, selected | 28.6°C19.5°C | 19.5°C | 78 | 9.3 | 13.714 h |
| September | 25.2°C15.5°C | 15.5°C | 80 | 7.4 | 12.512 h |
| October | 18.4°C9.2°C | 9.2°C | 83 | 8.5 | 11.211 h |
| November | 10.7°C2.4°C | 2.4°C | 84 | 8.3 | 10.010 h |
| December | 4.4°C-3.1°C | -3.1°C | 59 | 8.0 | 9.49 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Decatur in AugustUnited States · 59 kmHigh 28.3°C · Low 19.3°C · 77 mm rain
- Bloomington (Illinois), United States in AugustUnited States · 94 kmHigh 27.6°C · Low 18.7°C · 82 mm rain
- Peoria (Illinois), United States in AugustUnited States · 99 kmHigh 28.0°C · Low 19.4°C · 79 mm rain
- Champaign in AugustUnited States · 124 kmHigh 27.9°C · Low 18.7°C · 74 mm rain
- St. Louis in AugustUnited States · 139 kmHigh 30.4°C · Low 20.9°C · 74 mm rain
- O'Fallon in AugustUnited States · 143 kmHigh 30.1°C · Low 20.9°C · 76 mm rain
- Davenport in AugustUnited States · 207 kmHigh 27.6°C · Low 19.0°C · 90 mm rain
- Joliet in AugustUnited States · 232 kmHigh 27.4°C · Low 18.5°C · 93 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Springfield) is explained once on the Springfield (Illinois), United States year overview and on the Sources, method and limits page.