Climate averages 1991–2020
Roswell weather
in December.
A cool, wet month: the 11th warmest and the joint 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cool month in Roswell: daytime highs average 11.5°C and nights cool to about 3.0°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 117 mm of rain on roughly 10 days, which makes December a wet month (the joint 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 56 min on an average December day.
The nearest other city in this atlas is Sandy Springs (11 km away). In December its highs average 11.6°C, about as warm as Roswell, with 116 mm of rain.
Among the 498 cities listed in the United States, Roswell ranks joint 238th of 498 for the warmest December highs and joint 451st of 498 for the driest December (rainfall, lowest first). The mean December high of those 498 cities is 10.5°C; Roswell is 1.0°C warmer than that mean.
From December to January, average highs fall by 1.2°C to 10.3°C, and monthly rainfall falls from 117 mm to 116 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
Roswell climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 10.3°C1.4°C | 1.4°C | 116 | 10.4 | 10.210 h |
| February | 12.5°C2.9°C | 2.9°C | 117 | 10.1 | 10.911 h |
| March | 16.6°C6.3°C | 6.3°C | 120 | 10.3 | 12.012 h |
| April | 21.2°C10.4°C | 10.4°C | 102 | 9.6 | 13.013 h |
| May | 25.5°C15.2°C | 15.2°C | 85 | 9.8 | 13.914 h |
| June | 29.0°C19.5°C | 19.5°C | 104 | 13.6 | 14.414 h |
| July | 30.5°C21.5°C | 21.5°C | 104 | 14.6 | 14.214 h |
| August | 30.0°C21.1°C | 21.1°C | 104 | 12.6 | 13.413 h |
| September | 27.1°C18.2°C | 18.2°C | 91 | 8.6 | 12.412 h |
| October | 21.8°C12.3°C | 12.3°C | 86 | 7.2 | 11.411 h |
| November | 16.0°C6.5°C | 6.5°C | 99 | 8.5 | 10.410 h |
| December, selected | 11.5°C3.0°C | 3.0°C | 117 | 10.3 | 9.910 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
- Sandy Springs in DecemberUnited States · 11 kmHigh 11.6°C · Low 3.1°C · 116 mm rain
- Johns Creek in DecemberUnited States · 15 kmHigh 11.8°C · Low 3.3°C · 117 mm rain
- Atlanta in DecemberUnited States · 31 kmHigh 12.0°C · Low 3.1°C · 109 mm rain
- South Fulton in DecemberUnited States · 56 kmHigh 12.4°C · Low 4.0°C · 107 mm rain
- Athens, United States in DecemberUnited States · 91 kmHigh 12.5°C · Low 3.6°C · 113 mm rain
- East Chattanooga in DecemberUnited States · 142 kmHigh 10.6°C · Low 2.1°C · 128 mm rain
- Chattanooga in DecemberUnited States · 143 kmHigh 10.8°C · Low 2.3°C · 128 mm rain
- Macon in DecemberUnited States · 148 kmHigh 14.5°C · Low 5.1°C · 98 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 Roswell) is explained once on the Roswell year overview and on the Sources, method and limits page.
Johns Creek lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.