Climate averages 1991–2020
Rockford weather
in August.
A warm, moderately wet month: the 2nd warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a warm month in Rockford: daytime highs average 26.6°C and nights cool to about 17.7°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 87 mm of rain on roughly 10 days, which makes August a moderately wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 54 min on an average August day.
The nearest other city in this atlas is Elgin (72 km away). In August its highs average 26.8°C, about as warm as Rockford, with 93 mm of rain.
Among the 498 cities listed in the United States, Rockford ranks joint 406th of 498 for the warmest August highs and joint 307th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Rockford is 3.3°C cooler than that mean.
From August to September, average highs fall by 3.8°C to 22.8°C, and monthly rainfall falls from 87 mm to 84 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
Rockford 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-10.0°C | -10.0°C | 48 | 7.4 | 9.59 h |
| February | 0.7°C-8.1°C | -8.1°C | 45 | 7.0 | 10.511 h |
| March | 7.5°C-2.2°C | -2.2°C | 63 | 9.5 | 11.912 h |
| April | 14.1°C3.9°C | 3.9°C | 107 | 11.9 | 13.313 h |
| May | 20.4°C10.3°C | 10.3°C | 110 | 12.6 | 14.615 h |
| June | 25.6°C15.9°C | 15.9°C | 102 | 11.7 | 15.215 h |
| July | 27.6°C18.4°C | 18.4°C | 86 | 10.0 | 14.915 h |
| August, selected | 26.6°C17.7°C | 17.7°C | 87 | 9.7 | 13.914 h |
| September | 22.8°C13.7°C | 13.7°C | 84 | 8.7 | 12.513 h |
| October | 15.7°C7.2°C | 7.2°C | 73 | 8.7 | 11.111 h |
| November | 7.7°C0.2°C | 0.2°C | 60 | 7.9 | 9.810 h |
| December | 1.1°C-6.0°C | -6.0°C | 53 | 7.6 | 9.29 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
- Elgin in AugustUnited States · 72 kmHigh 26.8°C · Low 18.2°C · 93 mm rain
- Aurora (Illinois), United States in AugustUnited States · 86 kmHigh 26.9°C · Low 18.1°C · 92 mm rain
- Schaumburg in AugustUnited States · 87 kmHigh 26.7°C · Low 18.2°C · 93 mm rain
- Madison in AugustUnited States · 93 kmHigh 26.1°C · Low 17.2°C · 95 mm rain
- Arlington Heights in AugustUnited States · 94 kmHigh 26.4°C · Low 19.0°C · 93 mm rain
- Naperville in AugustUnited States · 95 kmHigh 26.8°C · Low 18.2°C · 92 mm rain
- Waukegan in AugustUnited States · 103 kmHigh 24.8°C · Low 21.0°C · 96 mm rain
- Bolingbrook in AugustUnited States · 106 kmHigh 26.8°C · Low 18.2°C · 95 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 Rockford) is explained once on the Rockford year overview and on the Sources, method and limits page.