Indianapolis - Climate of Summer's Heat

 Facts on Indy's Summer Heat!

With temperatures in the upper 80s and low 90s in the forecast for later this week, it's time to shift gears into a summer mindset, even though the mild and very wet weather the past few weeks has not felt too summerlike yet.

However, now is a good time to recall your tips for keeping safe in the hot weather and how to effectively 'beat the heat'. A great place to get started is:

While many times it feels much hotter than the 90s, in fact temperatures of 100 or better are very rare in the Indianapolis area. The last time the mercury reached to 100 or better was August 16, 1988; almost 21 years ago! 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 5 days in the 90s, and June sees 3 on average. September averages 2 days, and May just one. 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 1971-2000.

*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 19 August 25 April 24, 1925 July 8, 1877 September 1, 1960 October 8, 2007

Most in a year

Least in a Year

Last Year (2008)

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 10, 1936
July 25, 1934
July 24, 1934

*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.

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