A FROST ADVISORY has been issued for most of northern Illinois and southern Wisconsin beginning at 1am Tuesday, lasting through 8am Tuesday. Temperatures area wide are expected to fall into the low to mid 30s as skies clear during the overnight.
High pressure building in over the High Plains Monday will continue to settle into the Great Lakes and Midwest throughout the week. While afternoon highs will warm close to 70 degrees by the end of the week, we will experience a few more nights where overnight lows fall back into the 30s. Tuesday night it’s possible that some areas may need to go under a Freeze Warning, depending on how cold temperatures are forecast to drop. As of Monday evening, I’m forecasting an overnight low of 34 degrees.
Wednesday night should (hopefully) be our last frosty night as overnight lows are expected to warm back near average, or at least into the 40s. On average, our last Spring freeze (32 degrees) typically occurs within the last week of April. The latest date the Spring temperature fell to 32 degrees, or lower, was back on May 27th, 1992. Last year our last sub-32 degree temperature occurred on May 9th.