Indianapolis - Climate of Summer's Heat

 Facts on Indy's Summer Heat!

With the arrival of astronomical summer, it's time to shift gears into a summer mindset.

Now is a good time to recall your tips for keeping safe in the hot weather and how to effectively 'beat the heat'. Great places to get started are:

Despite the very hot temperatures experienced two summers ago in 2012, temperatures of 100 or better are very rare in general in the Indianapolis area. High temperatures made it to 100 or better nine times during June and July 2012, with the last date of triple digit heat on July 25, 2012 when the high reached 103 degrees. Prior to 2012 however, the last time the mercury reached to 101 or better was August 16, 1988! In the record books, it is not uncommon to see stretches of 20 or 30 years in Indianapolis without temperatures reaching 100 degrees.

On average, Indianapolis will see 18 days every year in the 90s. Most of them come in July, which averages 7 days a year of 90 degrees or better. August averages 6 days in the 90s, and June sees 3 on average and September averages 2 days. 90 degree days can happen in May, and even in late April and early October as well, but they are very rare. Here is some information on average and extremes of summer heat in the Indianapolis area.

*Average in this report refers to the average during the timeframe 1981-2010.

*Full records of temperature and precipitation at Indianapolis began in 1871.

  Temperatures in the 90s

Average 1st Day Average Last Day Earliest 1st Day Earliest Last Day Latest 1st Day Latest Last Day
June 18 August 29 April 24, 1925 July 8, 1877 September 1, 1960 October 8, 2007

Most in a year

Least in a Year

Last Year (2013)

58 in 1983

0 in 2004


Years with the most 90s



Number of Days











Years with the least 90s

Year Number of Days
2004 0
1877 2
1958 2
1992 2
1904 & 1950 3

Hottest Days Ever Recorded in Indianapolis Area

July 25, 1934 *
July 14, 1936
July 21, 1934
July 22, 1901
July 7, 2012
July 6, 2012
July 10, 1936

*The record from July 25, 1934 is considered unofficial because it was taken at the airport prior to the airport being recognized as the “official” temperature record station. However, this record has survived in local folklore for years, and can still be considered the hottest temperature ever recorded in the area ---unofficially. The record of 106 is considered the “official” record.

Return to News Archive is the U.S. government's official web portal to all federal, state and local government web resources and services.