Climate averages 1991–2020
Roswell weather
in August.
A hot, wet month: the 2nd warmest and the joint 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Roswell: daytime highs average 30.0°C and nights cool to about 21.1°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 104 mm of rain on roughly 13 days, which makes August a wet month (the joint 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 25 min on an average August day.
The nearest other city in this atlas is Sandy Springs (11 km away). In August its highs average 30.0°C, about as warm as Roswell, with 99 mm of rain.
Among the 498 cities listed in the United States, Roswell ranks joint 239th of 498 for the warmest August highs and joint 425th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Roswell is 0.1°C warmer than that mean.
From August to September, average highs fall by 2.8°C to 27.1°C, and monthly rainfall falls from 104 mm to 91 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
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, selected | 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
August in nearby cities
- Sandy Springs in AugustUnited States · 11 kmHigh 30.0°C · Low 21.2°C · 99 mm rain
- Johns Creek in AugustUnited States · 15 kmHigh 30.2°C · Low 21.4°C · 104 mm rain
- Atlanta in AugustUnited States · 31 kmHigh 30.1°C · Low 21.1°C · 96 mm rain
- South Fulton in AugustUnited States · 56 kmHigh 30.4°C · Low 21.6°C · 94 mm rain
- Athens, United States in AugustUnited States · 91 kmHigh 30.8°C · Low 21.5°C · 108 mm rain
- East Chattanooga in AugustUnited States · 142 kmHigh 30.3°C · Low 21.0°C · 85 mm rain
- Chattanooga in AugustUnited States · 143 kmHigh 30.5°C · Low 21.2°C · 85 mm rain
- Macon in AugustUnited States · 148 kmHigh 32.0°C · Low 22.4°C · 95 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.