Indianapolis climate
Indianapolis (Indiana, United States) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 11 °C52 °F, and about 1,141 mm45 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Indianapolis climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 134 | −719 | −327 | 753.0 | 28 |
| Feb | 338 | −621 | −130 | 682.7 | 25 |
| Mar | 1050 | −131 | 540 | 883.5 | 20 |
| Apr | 1763 | 542 | 1152 | 1114.4 | 6 |
| May | 2373 | 1253 | 1763 | 1194.7 | 0 |
| Jun | 2780 | 1762 | 2271 | 1345.3 | 0 |
| Jul | 2984 | 1966 | 2475 | 1124.4 | 0 |
| Aug | 2883 | 1864 | 2373 | 953.7 | 0 |
| Sep | 2678 | 1356 | 1967 | 813.2 | 0 |
| Oct | 1865 | 744 | 1254 | 933.7 | 2 |
| Nov | 1051 | 033 | 542 | 823.2 | 16 |
| Dec | 439 | −424 | 032 | 833.3 | 25 |
| Year | 2984 | −719 | 1152 | 1,14145 | 122 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 87% | 71% | 1.8 | 9:39 |
| Feb | 85% | 70% | 2.6 | 10:38 |
| Mar | 81% | 66% | 3.7 | 11:50 |
| Apr | 78% | 61% | 4.9 | 13:12 |
| May | 79% | 62% | 5.5 | 14:21 |
| Jun | 79% | 53% | 6.3 | 14:58 |
| Jul | 78% | 50% | 6.1 | 14:43 |
| Aug | 75% | 48% | 5.5 | 13:43 |
| Sep | 72% | 45% | 4.6 | 12:23 |
| Oct | 74% | 55% | 3.2 | 11:04 |
| Nov | 80% | 60% | 2.2 | 9:55 |
| Dec | 86% | 72% | 1.6 | 9:22 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Indianapolis is like
The warmest month is July, with an average high of 29 °C84 °F and a low of 19 °C66 °F. The coldest is January, when highs average 1 °C34 °F and lows −7 °C19 °F. Seasons are strongly marked: the warmest month is on average 26.5 °C47.8 °F warmer than the coldest.
It is wet, with about 1,141 mm45 in of precipitation per year. Rain is spread fairly evenly through the year. The wettest month is June (134 mm5.3 in), the driest is February (68 mm2.7 in).
Relative humidity ranges from 72% in September to 87% in January. The clearest skies (lowest average cloud amount, 45%) are typical of September. Average wind speed near the ground ranges from 7 km/h (4 mph) in August to 14 km/h (9 mph) in January. Daylight lasts from about 9.4 hours in December to 15.0 hours in June.
A lasting snow cover is typical in December–February, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, about 15 cm).
Best time to visit Indianapolis
Based on these averages, the most comfortable months for sightseeing and outdoor activities are August and September: average highs of 26 °C78 °F to 28 °C83 °F with 81 mm3.2 in to 95 mm3.7 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 1 °C34 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Indianapolis
- Winter (December–February) — highs 134 to 4 °C39 °F, lows −719 to −4 °C24 °F, about 75 mm3.0 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots and shoes with good grip, as frost is common.
- Spring (March–May) — highs 1050 to 23 °C73 °F, lows −131 to 12 °C53 °F, about 106 mm4.2 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Summer (June–August) — highs 2780 to 29 °C84 °F, lows 1762 to 19 °C66 °F, about 114 mm4.5 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1051 to 26 °C78 °F, lows 033 to 13 °C56 °F, about 85 mm3.4 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
How Indianapolis compares
Compared with Chicago, about 263 km to the northwest, Indianapolis is on average 1.4 °C2.6 °F warmer and receives 16% more precipitation (1,141 mm45 in vs 982 mm39 in). The difference is largest in May (5.2 °C9.4 °F warmer).
Of the 222 places in the United States covered by World Climates, Indianapolis is the 175th warmest by annual mean temperature and the 87th wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern: Satu Mare (Romania, Dfa), Baia Mare (Romania, Dfa) and Zagreb (Croatia, Dfa).
Nearby places
- Cincinnati 158 km · 13 °C55 °F · 1,116 mm44 in
- Dayton 168 km · 11 °C52 °F · 1,035 mm41 in
- Louisville 172 km · 13 °C56 °F · 1,272 mm50 in
- Fort Wayne 175 km · 10 °C51 °F · 966 mm38 in
- South Bend 213 km · 10 °C50 °F · 994 mm39 in
- Evansville 233 km · 14 °C56 °F · 1,243 mm49 in
- Lexington-Fayette 241 km · 13 °C55 °F · 1,231 mm48 in
- Lexington 246 km · 13 °C55 °F · 1,231 mm48 in
Frequently asked questions
What is the warmest month in Indianapolis?
July is the warmest month in Indianapolis, with an average high of 29 °C (84 °F) and an average low of 19 °C (66 °F).
What is the coldest month in Indianapolis?
January is the coldest month, with an average high of 1 °C (34 °F) and an average low of -7 °C (19 °F).
When does it rain the most in Indianapolis?
June is the wettest month with about 134 mm (5.3 in) of precipitation; February is the driest with about 68 mm (2.7 in).
What is the best time to visit Indianapolis?
Judging by long-term averages, the most comfortable months are August and September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.