Chicago spring temperatures on a warming trend over past 50 years

Cooler temperatures blowing into the area this weekend may be a welcome relief to Chicagoans as the city is in the midst of a top-10 warmest April on record to date.

Data from Chicago O'Hare shows the city just recorded 11 consecutive days of warmer-than-normal temperatures after a brisk start to the month.

From April 1 through April 18, temperatures are running a 4.9-degree fever compared to what is typical, currently ranking as the ninth-warmest April to date on record. 

Temperatures at Midway have been 4.8 degrees above normal, ranking as Midway's tenth-warmest April to this point.

As the climate warms, warm April temperatures are more frequent in the Upper Midwest. Though records extend back to 1958 at O'Hare, five of the ten warmest Aprils have come since 2000. The same is true at Midway. 

An analysis from Climate Central shows that springtime temperatures in Chicago are 1.5 degrees warmer than in 1970. Warm spring temperatures impact the growing season and can make allergies worse.