Climate averages 1991–2020
Roswell weather
in January.
A cool, wet month: the coolest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a cool month in Roswell: daytime highs average 10.3°C and nights cool to about 1.4°C. By daytime temperature it is the coolest month of the year.
Expect about 116 mm of rain on roughly 10 days, which makes January a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 10 min on an average January day.
The nearest other city in this atlas is Sandy Springs (11 km away). In January its highs average 10.4°C, about as warm as Roswell, with 114 mm of rain.
Among the 498 cities listed in the United States, Roswell ranks 240th of 498 for the warmest January highs and joint 452nd of 498 for the driest January (rainfall, lowest first). The mean January high of those 498 cities is 9.5°C; Roswell is 0.9°C warmer than that mean.
From January to February, average highs rise by 2.2°C to 12.5°C, and monthly rainfall rises from 116 mm to 117 mm.
The annual picture
January 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, selected | 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 | 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
January in nearby cities
- Sandy Springs in JanuaryUnited States · 11 kmHigh 10.4°C · Low 1.5°C · 114 mm rain
- Johns Creek in JanuaryUnited States · 15 kmHigh 10.6°C · Low 1.7°C · 116 mm rain
- Atlanta in JanuaryUnited States · 31 kmHigh 10.8°C · Low 1.5°C · 106 mm rain
- South Fulton in JanuaryUnited States · 56 kmHigh 11.2°C · Low 2.4°C · 106 mm rain
- Athens, United States in JanuaryUnited States · 91 kmHigh 11.3°C · Low 2.2°C · 112 mm rain
- East Chattanooga in JanuaryUnited States · 142 kmHigh 9.3°C · Low 0.4°C · 119 mm rain
- Chattanooga in JanuaryUnited States · 143 kmHigh 9.6°C · Low 0.6°C · 119 mm rain
- Macon in JanuaryUnited States · 148 kmHigh 13.3°C · Low 3.7°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 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.