Temperatures over last weekend and early this week have been cooler than normal. How much cooler? Here are the average high temperatures from May 13 to May 18 as a departure from normal. The values range from 6 to 9 degrees below normal in northern Illinois (dark shades of green) and from 9 to 15 degrees below normal (shades of blue) in central and southern Illinois. In other words, we are seeing high temperatures in the 50s and 60s instead of the 70s or low 80s.
According to the National Weather Service, we should start to warm up with high temperatures reaching into the 70s by the weekend and into the 80s next week.