Indianapolis has a humid continental climate that brings cold, bitter winters and warm, muggy summers to the city. Chilly air masses from Canada and warm air masses from the southern United States rule Indianapolis all year-long. Precipitation is abundant, thanks to the Gulf of Mexico that helps distribute moisture into the city.

Winters are short, cold, and sometimes snowy. The normal January temperature is about 27 degrees (F). Arctic blasts from Canada occasionally plague Indianapolis, and sometimes temperature readings of below 0 degrees (F) is recorded at the Indianapolis International Airport. Normal precipitation in January is about 2.48 inches, and snowfall for the month is just over 9 inches. Low pressure systems sometimes track northeast near the western edge of the Appalachian Mountains, bringing heavy snow to the city. And the so-called “Alberta Clippers,” which are fast-moving low pressure systems, sweep through Indiana rather quickly, often bringing a couple inches of snow.

Spring yields to a season of vast weather changes. If a high temperature of 80 degrees (F) was recorded at the Indianapolis airport on an April day, this can be followed by a cold front that is responsible for bringing much cooler temperatures falling into the 40s (F) in less than 24 hours. Thunderstorms are common, especially from mid-April through May. These storms can possibly contain destructive winds, large hail, or tornadoes, which are all typical spring-time patterns throughout the Midwest in the United States.

Summers are warm to hot, and often muggy. The July average temperature is about 76 degrees (F), but there are days when temperatures rise into the 90s (F) in the summertime. Triple-digit heat is rare in Indianapolis, but with the combination of the steamy moist air from the Gulf of Mexico (dew point) and the high temperatures, heat values can make people feel very uncomfortable. Thunderstorms continue to play another important role in Indianapolis throughout the summer, with an average precipitation of 4.42 inches being recorded in July.

Autumn is almost like spring. Noticeable changes in the weather is typical, especially in October and November. However, September and October are the sunniest months in Indianapolis, bringing pleasant weather along with the usual 70-degree (F) temperatures that are enjoyed by residents.

Indianapolis definitely has its share of weather variety. Having four distinct seasons, the city literally constantly experiences either very hot weather, very cold weather, a lot of rain, or a lot of snow. The best time of year to visit Indianapolis weather-wise for visitors and tourists is early autumn because sunshine and pleasant temperatures are quite more abundant at that time of year.


National Weather Service Climate