How Hot Will It Be In IL This Summer? Updated Temperature Outlook

ILLINOIS — What appears to be a rapid switch to an El Niño climate pattern could affect how summer shapes up in Illinois, according to an updated summer temperature outlook released Thursday by two private weather companies.

Some areas of the country could see the coolest summer temperatures since 2017, while it’s expected to be hotter than usual in the central U.S., according to the outlook from The Weather Company and Atmospheric G2.

Here’s how the outlook, which looks at temperatures relative to average, breaks it down for Illinois from June-August:

June: The temperature outlook looks to be near average for most of Illinois, with a small portion of southern Illinois looking slightly cooler, but still close to average.

July: Illinois continues to be in the near average temperature outlook, with a portion of northwest and western Illinois trending slightly above average temperatures, according to the outlook.

August: Heat will intensify from the Plains into the upper Midwest, according to the outlook. Illinois will be trending above average temperatures, with a portion of the eastern half of the state staying closer to average.

An El Niño is a naturally occurring warming of the surface waters in the central and eastern Pacific that can cause months- or years-long changes in temperature and precipitation. Its effects are generally experienced more in the winter months, but it can result in cooler-than-normal summers and increased rainfall.

With the switch to this climate pattern, the summer temperature outlook could be revised in the months ahead, according to Todd Crawford, the vice president of meteorology at Atmospheric G2 and the author of the outlook.

El Niño has not yet been officially declared. For that to happen, the pattern must be in place for at least three months. Central and eastern Pacific water temperatures already meet the threshold, according to Crawford.

Right now, here’s how things look for the country:

June: The summer is expected to start on a cool note across much of the Southwest, while the rest of the country’s southern tier of states should see near-average or cooler-than-normal temperatures. Along the northern tier of states, temperatures are expected to be warmer.

July: The heat is expected to push south through the plains to the Southwest, setting up a warm up from cool June temperatures in the southern Rockies and southern Plains. Some areas of both coasts, particularly southern California, could remain near average or slightly cooler.

August: The heat is expected to persist or even intensify from the Plains to the upper Midwest, but some areas of the Northeast and West Coast are expected to see near-average or slightly cooler temperatures.