Historical weather data, all-time temperature records, and monthly climate averages for Oak Forest, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4 in Oak Forest typically lands right in the heart of that unpredictable shoulder season, with an average high of 55° and low of 34°. The date's range over 72 years tells the whole story: it's hit 80° as recently as 2012, and plunged to 18° back in 1982. There's a 43% chance of rain today, though snow is nearly off the table at just 1%.
Oak Forest plays in the extremes — this is a place that has cooked at 103° in August 1988 and frozen at -27° in January 1985, a swing of 130 degrees. A single July day in 1996 dropped 6.55 inches of rain, and a February 2011 snowstorm buried the area under 19 inches in one shot. This is classic Midwest weather: no half measures.
Summers are the main event, with the week of July 16–22 averaging a high of 85° — also the wettest stretch of the year at 1.29 inches. Winters bite hard, with January highs barely scraping 30° during the coldest weeks. If you're planning a visit, May through September is your window; everything else is a gamble.