Climate averages 1991–2020
Decatur weather
in June.
A warm, wet month: the 3rd warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
June is a warm month in Decatur: daytime highs average 27.1°C and nights cool to about 17.9°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 110 mm of rain on roughly 11 days, which makes June a wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 57 min on an average June day.
The nearest other city in this atlas is Springfield (Illinois), United States (59 km away). In June its highs average 27.4°C, about as warm as Decatur, with 110 mm of rain.
Among the 498 cities listed in the United States, Decatur ranks joint 271st of 498 for the warmest June highs and joint 402nd of 498 for the driest June (rainfall, lowest first). The mean June high of those 498 cities is 27.9°C; Decatur is 0.8°C cooler than that mean.
From June to July, average highs rise by 1.7°C to 28.8°C, and monthly rainfall falls from 110 mm to 91 mm.
The annual picture
June 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 | 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, selected | 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
June in nearby cities
- Springfield (Illinois), United States in JuneUnited States · 59 kmHigh 27.4°C · Low 18.0°C · 110 mm rain
- Champaign in JuneUnited States · 68 kmHigh 26.7°C · Low 17.3°C · 105 mm rain
- Bloomington (Illinois), United States in JuneUnited States · 72 kmHigh 26.5°C · Low 17.2°C · 110 mm rain
- Peoria (Illinois), United States in JuneUnited States · 109 kmHigh 26.9°C · Low 17.8°C · 111 mm rain
- St. Louis in JuneUnited States · 172 kmHigh 29.1°C · Low 19.3°C · 106 mm rain
- Lafayette (Indiana), United States in JuneUnited States · 188 kmHigh 26.4°C · Low 17.0°C · 110 mm rain
- O'Fallon in JuneUnited States · 189 kmHigh 28.6°C · Low 19.3°C · 101 mm rain
- Joliet in JuneUnited States · 201 kmHigh 26.3°C · Low 16.6°C · 110 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.