Chicago, Illinois – A stronger spring signal is taking shape across Illinois heading into early March, with confidence increasing that both temperatures and precipitation trend above seasonal averages during the Feb. 28 through Mar. 13 period.
According to the National Weather Service Climate Prediction Center, Illinois carries a 50% to 60% probability of above-normal temperatures in the Week 3-4 outlook. Precipitation probabilities also rise into the 50% to 60% range, indicating a higher likelihood of wetter-than-average conditions statewide.
The warmer and wetter signal spans the Interstate 55 corridor from Chicago through Springfield to the St. Louis metro east, west along Interstate 80 across northern Illinois, and south along Interstate 57 toward Carbondale. This broader atmospheric setup favors fewer prolonged Arctic intrusions compared to typical late-February standards.
The elevated precipitation outlook suggests a more active storm track across the Midwest and Mississippi Valley. While the long-range guidance does not specify exact storm timing or precipitation type, it does point toward a greater probability of systems moving through Illinois during the two-week window.
Major population centers including Chicago, Rockford, Peoria, Springfield and Champaign fall within both the warmer and wetter zones. The Week 3-4 outlook reflects large-scale atmospheric trends rather than specific day-to-day conditions.
Additional refinements are expected as the late-February to mid-March timeframe approaches and shorter-range guidance provides greater clarity on individual systems.
