Climate averages 1991–2020
Wilmington (Delaware), United States weather
in December.
A cold, wet month: the 10th warmest and the joint 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Wilmington (Delaware), United States: daytime highs average 6.9°C and nights cool to about -0.3°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 100 mm of rain on roughly 9 days, which makes December a wet month (the joint 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 25 min on an average December day.
The nearest other city in this atlas is Philadelphia (40 km away). In December its highs average 7.0°C, about as warm as Wilmington (Delaware), United States, with 100 mm of rain.
Among the 498 cities listed in the United States, Wilmington (Delaware), United States ranks joint 308th of 498 for the warmest December highs and joint 373rd of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Wilmington (Delaware), United States is 3.6°C cooler than that mean.
From December to January, average highs fall by 2.4°C to 4.5°C, and monthly rainfall falls from 100 mm to 82 mm.
The annual picture
December 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 | 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, selected | 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
December in nearby cities
- Philadelphia in DecemberUnited States · 40 kmHigh 7.0°C · Low -0.4°C · 100 mm rain
- Camden in DecemberUnited States · 42 kmHigh 7.2°C · Low -0.4°C · 100 mm rain
- Cherry Hill in DecemberUnited States · 49 kmHigh 7.1°C · Low -0.1°C · 100 mm rain
- Reading, United States in DecemberUnited States · 73 kmHigh 5.9°C · Low -1.3°C · 94 mm rain
- Trenton in DecemberUnited States · 86 kmHigh 6.7°C · Low -0.9°C · 102 mm rain
- Allentown in DecemberUnited States · 96 kmHigh 5.4°C · Low -2.4°C · 101 mm rain
- Bethlehem, United States in DecemberUnited States · 99 kmHigh 5.4°C · Low -2.4°C · 104 mm rain
- Baltimore in DecemberUnited States · 105 kmHigh 7.1°C · Low -0.4°C · 109 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.