Indianapolis, IN Climate & Monthly Averages
The climate of Indianapolis
Indianapolis has a humid subtropical climate, marked by hot, humid summers and generally mild winters. Average daytime highs range from about 38°F (3°C) in January to around 85°F (29°C) in July, and the city records roughly 130 days of measurable precipitation a year.
Climate quick facts
- Hottest month: July - highs near 85°F (29°C)
- Coldest month: January - highs near 38°F (3°C)
- Record high: 95°F (35°C) · Record low: -18°F (-28°C) (2015–2024)
- Wettest month: March (13 rainy days) · Sunniest: July (11.7 h sun/day)
- Climate type: humid subtropical - hot, humid summers and generally mild winters
- Snow: about 10 days a year
Temperatures through the year
The warmest stretch of the year centers on July. Highs average 85°F (29°C) and overnight lows stay near 67°F (20°C). The coolest month is January, with typical highs of 38°F (3°C) and lows around 23°F (-5°C). Based on 2015–2024 weather data, temperatures have reached as high as 95°F (35°C) and dropped as low as -18°F (-28°C).
Rain, sun and snow
March is usually the wettest month. It brings about 5.3 inches (135 mm) of rain over 13 days, while September is the driest. July brings the most sunshine, averaging 11.7 hours of sun a day. Snow falls on about 10 days in a typical year, mostly from November through April.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 38° | 23° | 10 | 3.4 in | 5.1 h/day | 72% |
| February | 43° | 25° | 9 | 3.2 in | 6.6 h/day | 69% |
| March | 52° | 34° | 13 | 5.3 in | 7.4 h/day | 68% |
| April | 62° | 43° | 12 | 4.1 in | 8.7 h/day | 66% |
| May | 73° | 55° | 14 | 4.9 in | 9.9 h/day | 70% |
| June | 82° | 64° | 12 | 4.0 in | 11.6 h/day | 67% |
| July | 85° | 67° | 13 | 4.6 in | 11.7 h/day | 73% |
| August | 83° | 66° | 11 | 3.5 in | 11.3 h/day | 72% |
| September | 79° | 61° | 7 | 2.9 in | 10.0 h/day | 69% |
| October | 66° | 49° | 10 | 3.1 in | 8.0 h/day | 69% |
| November | 52° | 36° | 9 | 3.2 in | 6.4 h/day | 71% |
| December | 44° | 29° | 9 | 3.5 in | 5.1 h/day | 74% |
Indianapolis month by month
Indianapolis weather in January
January brings highs around 38°F (3°C), lows near 23°F (-5°C), about 10 wet days and roughly 3 snowy days - typically the coldest month of the year in Indianapolis.
Indianapolis weather in February
February brings highs around 43°F (6°C), lows near 25°F (-4°C), about 9 wet days and roughly 3 snowy days.
Indianapolis weather in March
March brings highs around 52°F (11°C), lows near 34°F (1°C), about 13 wet days and roughly 1 snowy days - typically the wettest month of the year in Indianapolis.
Indianapolis weather in April
April brings highs around 62°F (17°C), lows near 43°F (6°C), about 12 wet days.
Indianapolis weather in May
May brings highs around 73°F (23°C), lows near 55°F (13°C), about 14 wet days.
Indianapolis weather in June
June brings highs around 82°F (28°C), lows near 64°F (18°C), about 12 wet days.
Indianapolis weather in July
July brings highs around 85°F (29°C), lows near 67°F (20°C), about 13 wet days - typically the hottest month and the sunniest month of the year in Indianapolis.
Indianapolis weather in August
August brings highs around 83°F (28°C), lows near 66°F (19°C), about 11 wet days.
Indianapolis weather in September
September brings highs around 79°F (26°C), lows near 61°F (16°C), about 7 wet days - typically the driest month of the year in Indianapolis.
Indianapolis weather in October
October brings highs around 66°F (19°C), lows near 49°F (10°C), about 10 wet days.
Indianapolis weather in November
November brings highs around 52°F (11°C), lows near 36°F (2°C), about 9 wet days.
Indianapolis weather in December
December brings highs around 44°F (6°C), lows near 29°F (-2°C), about 9 wet days and roughly 1 snowy days.
Seasons in Indianapolis
Spring (March through May)
Spring in Indianapolis is mild, with daytime highs averaging 63°F (17°C) and nights around 44°F (7°C); expect showers on roughly 39 days across the season.
Summer (June through August)
Summer in Indianapolis runs hot, with daytime highs averaging 83°F (29°C) and nights around 66°F (19°C); expect showers on roughly 36 days across the season. With the humidity factored in, afternoons often feel hotter than the thermometer reads - run the numbers through the humidity and dew point converter to see why.
Fall (September through November)
Fall in Indianapolis stays on the cool side of mild, with daytime highs averaging 66°F (19°C) and nights around 49°F (9°C); expect showers on roughly 26 days across the season.
Winter (December through February)
Winter in Indianapolis is chilly, with daytime highs averaging 41°F (5°C) and nights around 26°F (-4°C); expect showers on roughly 29 days across the season, plus around 8 snowy days.
Climate questions, answered
What is the average temperature in Indianapolis?
Is Indianapolis hot in summer?
Is Indianapolis cold in winter?
How many rainy days does Indianapolis get in a year?
Best time to visit Indianapolis
The best time to visit Indianapolis is generally August to October and June, when warm days, manageable rainfall and plenty of daylight line up. Daytime temperatures in that window typically sit near 78°F (25°C).
Pack for Indianapolis with a heavy insulated coat, hat and gloves for winter; a compact umbrella or rain shell - showers are a regular feature. Evenings can feel noticeably cooler than afternoons - July nights average 67°F (20°C).
Indianapolis temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.