Historical weather data, all-time temperature records, and monthly climate averages for Sterling, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4 in Sterling sits in that classic spring in-between zone — 128 years of records show an average high of 56° and low of 34°, with a real spread between extremes. The date has seen everything from a balmy 82° back in 1929 to a bitter 17° in 1936. There's a 35% chance of rain today, but snow is nearly off the table at just 1%.
Sterling's weather has real teeth at both ends — the thermometer has swung from a scorching 110° in July 1936 to a brutal -32° in January 2009, a 142-degree range that puts the region's continental climate on full display. A single day in July 1922 dumped over 5 inches of rain, and a February 1933 snowstorm buried the area under 14 inches.
Sterling runs hot in summer and cold in winter with little ambiguity — peak warmth arrives mid-July with average highs of 85-86°, while early January chills down to just 30°. If you're trying to dodge rain, avoid mid-June, which is the wettest stretch of the year at over an inch of precip per week. Spring and fall offer the most comfortable temperatures, with April and October both averaging highs in the low 60s.