Sunday the temperature in Chicago couldn't crest 16°C, a temperature more typical of March than of May. Today it's already 26°C and rising—the warmest Chicago has seen since October 11th. Tomorrow will be even warmer, possibly passing 31°C. But don't worry; this is Chicago, so March will return this weekend:
Computer models are advertising a sharp pull back in temperatures by this weekend. A pool of unseasonably cool air is to settle over the Midwest, spinning up a blustery storm system over Illinois which is to remain essentially stalled in place over the coming weekend. It's a scenario which could generate gusty easterly winds in Chicago and temperatures which fall back to the low 10s Saturday and Sunday. That the system is to be part of a blocking pattern is the reason it's to be such a slow-mover. Model rainfall estimates put potential weekend rainfall of up to an inch down here.
NOAA also released new data this past week confirming what we in Chicago have suspected for a while: our autumns are getting sunnier while our springs and summers are getting gloomier. Winters, however, remain unchanged in their character building cold.