Climate averages 1991–2020
Decatur weather
in April.
A mild, wet month: the 7th warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
April is a mild month in Decatur: daytime highs average 17.2°C and nights cool to about 6.7°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 118 mm of rain on roughly 12 days, which makes April a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 14 min on an average April day.
The nearest other city in this atlas is Springfield (Illinois), United States (59 km away). In April its highs average 17.4°C, about as warm as Decatur, with 116 mm of rain.
Among the 498 cities listed in the United States, Decatur ranks joint 309th of 498 for the warmest April highs and joint 455th of 498 for the driest April (rainfall, lowest first). The mean April high of those 498 cities is 19.4°C; Decatur is 2.2°C cooler than that mean.
From April to May, average highs rise by 5.3°C to 22.5°C, and monthly rainfall rises from 118 mm to 122 mm.
The annual picture
April 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
Decatur climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.8°C-6.3°C | -6.3°C | 69 | 8.5 | 9.710 h |
| February | 4.6°C-4.7°C | -4.7°C | 59 | 7.6 | 10.711 h |
| March | 10.7°C0.7°C | 0.7°C | 83 | 9.7 | 11.912 h |
| April, selected | 17.2°C6.7°C | 6.7°C | 118 | 11.7 | 13.213 h |
| May | 22.5°C12.8°C | 12.8°C | 122 | 13.2 | 14.414 h |
| June | 27.1°C17.9°C | 17.9°C | 110 | 10.9 | 14.915 h |
| July | 28.8°C19.9°C | 19.9°C | 91 | 10.3 | 14.715 h |
| August | 28.3°C19.3°C | 19.3°C | 77 | 8.4 | 13.714 h |
| September | 25.0°C15.4°C | 15.4°C | 82 | 7.3 | 12.512 h |
| October | 18.2°C9.1°C | 9.1°C | 88 | 8.6 | 11.211 h |
| November | 10.5°C2.3°C | 2.3°C | 88 | 8.7 | 10.010 h |
| December | 4.3°C-3.1°C | -3.1°C | 63 | 8.7 | 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
April in nearby cities
- Springfield (Illinois), United States in AprilUnited States · 59 kmHigh 17.4°C · Low 6.9°C · 116 mm rain
- Champaign in AprilUnited States · 68 kmHigh 16.8°C · Low 6.1°C · 115 mm rain
- Bloomington (Illinois), United States in AprilUnited States · 72 kmHigh 16.3°C · Low 5.8°C · 113 mm rain
- Peoria (Illinois), United States in AprilUnited States · 109 kmHigh 16.4°C · Low 6.3°C · 112 mm rain
- St. Louis in AprilUnited States · 172 kmHigh 19.1°C · Low 8.4°C · 117 mm rain
- Lafayette (Indiana), United States in AprilUnited States · 188 kmHigh 16.4°C · Low 5.7°C · 109 mm rain
- O'Fallon in AprilUnited States · 189 kmHigh 18.7°C · Low 8.5°C · 114 mm rain
- Joliet in AprilUnited States · 201 kmHigh 15.4°C · Low 4.8°C · 112 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 Decatur) is explained once on the Decatur year overview and on the Sources, method and limits page.