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The temperatures in Indianapolis in September are comfortable with low of 15°C and and high up to 25°C.
You can expect about 3 to 8 days of rain in Indianapolis during the month of September. 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 Indianapolis in September 2025.
If you’re planning to visit Indianapolis in the near future, we highly recommend that you review the 14 day weather forecast for Indianapolis before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 0° / -6° | 5 | 15 | 11 | 43 mm | Awful | Indianapolis in January |
| February | 2° / -4° | 4 | 14 | 10 | 44 mm | Awful | Indianapolis in February |
| March | 10° / 2° | 6 | 20 | 5 | 58 mm | Bad | Indianapolis in March |
| April | 16° / 7° | 6 | 23 | 1 | 79 mm | Good | Indianapolis in April |
| May | 22° / 13° | 7 | 24 | 0 | 90 mm | Ok | Indianapolis in May |
| June | 27° / 18° | 6 | 24 | 0 | 90 mm | Perfect | Indianapolis in June |
| July | 28° / 19° | 6 | 25 | 0 | 78 mm | Perfect | Indianapolis in July |
| August | 28° / 18° | 4 | 27 | 0 | 59 mm | Perfect | Indianapolis in August |
| September | 25° / 15° | 3 | 27 | 0 | 54 mm | Perfect | Indianapolis in September |
| October | 17° / 9° | 5 | 26 | 0 | 55 mm | Good | Indianapolis in October |
| November | 10° / 3° | 4 | 24 | 2 | 44 mm | Bad | Indianapolis in November |
| December | 4° / -2° | 4 | 19 | 8 | 45 mm | Awful | Indianapolis in December |