What is the hottest month in Indianapolis?

July is Indianapolis's hottest month, with the highest average daily high of the year. The month-by-month table above shows Indianapolis's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.

What is the coldest month in Indianapolis?

January is Indianapolis's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.

How much does it rain in Indianapolis?

Indianapolis's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.

What months are best to visit Indianapolis?

The most comfortable months in Indianapolis are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.

Has Indianapolis gotten hotter?

Yes. The warming-stripes chart above plots Indianapolis's annual mean temperature for every complete year of station data from 1948 to 2025, and the trend line fitted to 1948–2025 rises about 3.0°F (+0.39°F per decade) — recent decades average warmer than the start of that window.

What is the record high temperature in Indianapolis?

Indianapolis's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1948, so they capture the most extreme heat on record, not just a typical summer day.

What is the record low temperature in Indianapolis?

Indianapolis's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1948, so it reflects the coldest day on record rather than an average winter low.

Indianapolis, Indiana Climate

Indianapolis weather by month — average highs and lows, rainfall, all-time records, and the warming record since 1948

Hottest month: 85°FJuly average high
Coldest month: 21°FJanuary average low
Precipitation: 43.6 ina year
Snowfall: 25.5 ina year

1991–2020 NOAA climate normals

At 10:39 AM EDT on Sep 21 it was 62°F in Indianapolis — 4° below the 66°F typical for that hour (estimated from the Sep 21 normal high of 76°F and low of 55°F, interpolated from the monthly normals).

Indianapolis weather by month

Average high, low, and rainfall for every month, from Indianapolis’s 1991–2020 climate normals, the standard 30-year reference period. Each band runs from the month’s average low to its average high: a tall band is a big day-to-night swing.

36°21°

3.1″Jan

41°24°

2.4″Feb

52°33°

3.7″Mar

64°43°

4.3″Apr

73°54°

4.8″May

82°63°

5.0″Jun

85°66°

4.4″Jul

84°65°

3.2″Aug

78°57°

3.1″Sep

66°46°

3.2″Oct

52°35°

3.5″Nov

40°26°

2.9″Dec

Average high → low (°F)Rainfall (inches)1991–2020 normals

Indianapolis monthly weather averages — average high, average low, and rainfall for each month, from the 1991–2020 U.S. Climate Normals (NOAA).
Month	Avg High	Avg Low	Rainfall
January	36°F	21°F	3.1 in
February	41°F	24°F	2.4 in
March	52°F	33°F	3.7 in
April	64°F	43°F	4.3 in
May	73°F	54°F	4.8 in
June	82°F	63°F	5.0 in
July	85°F	66°F	4.4 in
August	84°F	65°F	3.2 in
September	78°F	57°F	3.1 in
October	66°F	46°F	3.2 in
November	52°F	35°F	3.5 in
December	40°F	26°F	2.9 in
Annual	63°F	44°F	43.6 in

Indianapolis’s warming record since 1948

Indianapolis has warmed 3.0°F since 1948 (+0.39°F per decade, 1948–2025 trend)

Not what a typical year looks like, but how the typical year has changed. Each stripe is one complete year’s average temperature at the station, 1948 to 2025, colored against the mean of those years: blue for cooler years, red for warmer ones. The figure under the stripes is the least-squares trend line fitted to 1948–2025 — Indianapolis averages about 3.0°F warmer by that trend than in 1948.

Compared with the national rankingThe fastest-warming cities ranking fits every city to the same years, 1970–2025, so rates compare like for like. Over that window Indianapolis warms at +0.58°F per decade, #29 of 66. The figure above uses the station’s own record, 1948–2025, so the two rates differ.

Indianapolis rainfall by month

Indianapolis averages 43.6 inches of precipitation a year. The wettest month is June and the driest is February.

Indianapolis also averages 25.5 inches of snowfall a year.

Indianapolis temperature records

All-time record high: 105°Fset July 6, 2012
All-time record low: -27°Fset January 19, 1994

Records are drawn from the nearest long-term weather station’s full daily history, so they capture the most extreme single day Indianapolis has recorded — not a typical seasonal high or low.

Frequently asked

What is the hottest month in Indianapolis?: July is Indianapolis's hottest month, with the highest average daily high of the year. The month-by-month table above shows Indianapolis's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.
What is the coldest month in Indianapolis?: January is Indianapolis's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.
How much does it rain in Indianapolis?: Indianapolis's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.
What months are best to visit Indianapolis?: The most comfortable months in Indianapolis are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.
Has Indianapolis gotten hotter?: Yes. The warming-stripes chart above plots Indianapolis's annual mean temperature for every complete year of station data from 1948 to 2025, and the trend line fitted to 1948–2025 rises about 3.0°F (+0.39°F per decade) — recent decades average warmer than the start of that window.
What is the record high temperature in Indianapolis?: Indianapolis's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1948, so they capture the most extreme heat on record, not just a typical summer day.
What is the record low temperature in Indianapolis?: Indianapolis's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1948, so it reflects the coldest day on record rather than an average winter low.