Climate averages 1991–2020
Wilmington (Delaware), United States weather
in August.
A hot, wet month: the 2nd warmest and the joint 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Wilmington (Delaware), United States: daytime highs average 28.2°C and nights cool to about 19.9°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 100 mm of rain on roughly 10 days, which makes August a wet month (the joint 9th 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 Philadelphia (40 km away). In August its highs average 28.8°C, 0.6°C warmer than Wilmington (Delaware), United States, with 95 mm of rain.
Among the 498 cities listed in the United States, Wilmington (Delaware), United States ranks joint 313th of 498 for the warmest August highs and joint 399th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Wilmington (Delaware), United States is 1.7°C cooler than that mean.
From August to September, average highs fall by 3.6°C to 24.6°C, and monthly rainfall rises from 100 mm to 107 mm.
The annual picture
August in context
Monthly rainfall
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
Wilmington (Delaware), United States climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.5°C-3.0°C | -3.0°C | 82 | 9.2 | 9.710 h |
| February | 6.1°C-2.4°C | -2.4°C | 76 | 8.7 | 10.711 h |
| March | 10.6°C1.2°C | 1.2°C | 105 | 10.7 | 11.912 h |
| April | 16.9°C6.8°C | 6.8°C | 92 | 10.5 | 13.213 h |
| May | 22.0°C12.4°C | 12.4°C | 89 | 10.8 | 14.314 h |
| June | 26.8°C17.7°C | 17.7°C | 99 | 10.4 | 14.915 h |
| July | 29.3°C20.7°C | 20.7°C | 99 | 10.9 | 14.715 h |
| August, selected | 28.2°C19.9°C | 19.9°C | 100 | 10.4 | 13.714 h |
| September | 24.6°C16.3°C | 16.3°C | 107 | 9.6 | 12.512 h |
| October | 18.2°C10.0°C | 10.0°C | 91 | 8.1 | 11.211 h |
| November | 12.1°C4.1°C | 4.1°C | 75 | 7.9 | 10.010 h |
| December | 6.9°C-0.3°C | -0.3°C | 100 | 9.0 | 9.49 h |
Rainfall is the average of the 30 separate monthly totals. A rain 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
- Philadelphia in AugustUnited States · 40 kmHigh 28.8°C · Low 19.9°C · 95 mm rain
- Camden in AugustUnited States · 42 kmHigh 28.7°C · Low 19.9°C · 95 mm rain
- Cherry Hill in AugustUnited States · 49 kmHigh 28.5°C · Low 20.0°C · 95 mm rain
- Reading, United States in AugustUnited States · 73 kmHigh 28.7°C · Low 18.9°C · 85 mm rain
- Trenton in AugustUnited States · 86 kmHigh 28.4°C · Low 19.3°C · 102 mm rain
- Allentown in AugustUnited States · 96 kmHigh 28.1°C · Low 17.9°C · 93 mm rain
- Bethlehem, United States in AugustUnited States · 99 kmHigh 28.0°C · Low 17.9°C · 93 mm rain
- Baltimore in AugustUnited States · 105 kmHigh 28.6°C · Low 20.2°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 Wilmington) is explained once on the Wilmington (Delaware), United States year overview and on the Sources, method and limits page.