Climate averages 1991–2020
Allentown weather
in December.
A cold, wet month: the 10th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Allentown: daytime highs average 5.4°C and nights cool to about -2.4°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 101 mm of rain on roughly 9 days, which makes December a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 20 min on an average December day.
The nearest other city in this atlas is Bethlehem, United States (10 km away). In December its highs average 5.4°C, about as warm as Allentown, with 104 mm of rain.
Among the 498 cities listed in the United States, Allentown ranks joint 351st of 498 for the warmest December highs and joint 381st of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Allentown is 5.2°C cooler than that mean.
From December to January, average highs fall by 2.6°C to 2.8°C, and monthly rainfall falls from 101 mm to 87 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
Allentown climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.8°C-5.7°C | -5.7°C | 87 | 9.5 | 9.610 h |
| February | 4.4°C-5.2°C | -5.2°C | 77 | 9.1 | 10.611 h |
| March | 9.1°C-1.3°C | -1.3°C | 103 | 11.0 | 11.912 h |
| April | 15.8°C4.5°C | 4.5°C | 99 | 10.6 | 13.313 h |
| May | 21.3°C10.4°C | 10.4°C | 95 | 11.5 | 14.414 h |
| June | 26.2°C15.6°C | 15.6°C | 103 | 11.3 | 15.015 h |
| July | 29.1°C18.6°C | 18.6°C | 98 | 11.2 | 14.815 h |
| August | 28.1°C17.9°C | 17.9°C | 93 | 10.1 | 13.814 h |
| September | 24.1°C14.1°C | 14.1°C | 113 | 8.8 | 12.513 h |
| October | 17.2°C7.8°C | 7.8°C | 100 | 8.9 | 11.211 h |
| November | 10.8°C2.1°C | 2.1°C | 81 | 8.0 | 10.010 h |
| December, selected | 5.4°C-2.4°C | -2.4°C | 101 | 9.4 | 9.39 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
- Bethlehem, United States in DecemberUnited States · 10 kmHigh 5.4°C · Low -2.4°C · 104 mm rain
- Reading, United States in DecemberUnited States · 48 kmHigh 5.9°C · Low -1.3°C · 94 mm rain
- Trenton in DecemberUnited States · 77 kmHigh 6.7°C · Low -0.9°C · 102 mm rain
- Philadelphia in DecemberUnited States · 78 kmHigh 7.0°C · Low -0.4°C · 100 mm rain
- Camden in DecemberUnited States · 82 kmHigh 7.2°C · Low -0.4°C · 100 mm rain
- Cherry Hill in DecemberUnited States · 84 kmHigh 7.1°C · Low -0.1°C · 100 mm rain
- Scranton in DecemberUnited States · 90 kmHigh 3.4°C · Low -3.4°C · 83 mm rain
- Edison in DecemberUnited States · 92 kmHigh 6.3°C · Low -0.8°C · 102 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 Allentown) is explained once on the Allentown year overview and on the Sources, method and limits page.