Climate averages 1991–2020
Springfield (Illinois), United States weather
by month.
See how the year changes. July has the highest average daily maximum; February has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: September
Long-term climate patterns, not a forecast for a particular trip.
Across the year Springfield (Illinois), United States averages a daytime high of 16.8°C and a nighttime low of 7.6°C, with about 1,015 mm of rain on roughly 114 days. July is the warmest month (average high 29.1°C) and January the coolest (1.9°C). May is the wettest month with 117 mm; February is the driest with 57 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): September. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Springfield
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 | 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
Nearby cities
- DecaturUnited States · 59 kmHigh 16.6°C · Low 7.5°C · 1,050 mm rain a year
- Bloomington (Illinois), United StatesUnited States · 94 kmHigh 15.8°C · Low 6.7°C · 1,008 mm rain a year
- Peoria (Illinois), United StatesUnited States · 99 kmHigh 15.9°C · Low 7.1°C · 979 mm rain a year
- ChampaignUnited States · 124 kmHigh 16.2°C · Low 7.0°C · 1,027 mm rain a year
- St. LouisUnited States · 139 kmHigh 18.6°C · Low 9.1°C · 1,066 mm rain a year
- O'FallonUnited States · 143 kmHigh 18.3°C · Low 9.1°C · 1,030 mm rain a year
- DavenportUnited States · 207 kmHigh 15.1°C · Low 6.3°C · 963 mm precipitation a year
- JolietUnited States · 232 kmHigh 15.2°C · Low 6.1°C · 988 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-6, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 39.80°, -89.60° (4 km from the city centre), adjusted down by 0.1°C for the difference between the city's elevation (184 m) and the cell's (172 m). Rain comes from the 0.25° cell at 39.75°, -89.75°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.