Click on a day for an hourly weather forecast
The temperatures in Decatur in August are comfortable with low of 18°C and and high up to 27°C.
You can expect about 3 to 8 days of rain in Decatur during the month of August. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Decatur in August 2025.
If you’re planning to visit Decatur in the near future, we highly recommend that you review the 14 day weather forecast for Decatur before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 0° / -6° | 5 | 15 | 11 | 52 mm | Awful | Decatur in January |
| February | 2° / -5° | 4 | 15 | 10 | 53 mm | Awful | Decatur in February |
| March | 10° / 2° | 7 | 20 | 4 | 78 mm | Awful | Decatur in March |
| April | 16° / 7° | 7 | 22 | 1 | 113 mm | Ok | Decatur in April |
| May | 22° / 14° | 8 | 23 | 0 | 127 mm | Ok | Decatur in May |
| June | 27° / 18° | 7 | 23 | 0 | 140 mm | Good | Decatur in June |
| July | 28° / 19° | 6 | 25 | 0 | 107 mm | Perfect | Decatur in July |
| August | 27° / 18° | 5 | 26 | 0 | 98 mm | Perfect | Decatur in August |
| September | 25° / 15° | 4 | 26 | 0 | 75 mm | Perfect | Decatur in September |
| October | 18° / 9° | 5 | 26 | 0 | 75 mm | Good | Decatur in October |
| November | 10° / 3° | 5 | 24 | 2 | 65 mm | Bad | Decatur in November |
| December | 4° / -2° | 5 | 19 | 7 | 52 mm | Awful | Decatur in December |