CHICAGO (CBS) — According to the National Weather Service, Chicago O’Hare reached 91 degrees Fahrenheit Monday, marking the 12th 90 degree reading in Chicago so far this year.

The average annual number of 90+ degree days is 16-17 days per year in Chicago. Seasonable 80-degree temperatures are expected through the middle of the week. The National Weather Service reports there will be more opportunities for temperatures to reach into the 90s later in the week through next Monday.