Climate change in Clark County, Illinois
Since 1979, Clark County, Illinois has warmed 2.6°F, with 5 more days above 90°F, 1 more nights above 70°F and 5% more precipitation a year. Its climate in 1996–2025 is most like Lawrence County, IL's was in 1951–1980.
- Average temperature: +2.6°F
- Summer highs (Jun–Aug): +0.8°F
- Winter lows (Dec–Feb): +4.1°F
- Precipitation: +5%
- Wettest day of the year: +17%
- Longest dry spell: −2 days
- Days above 90°F: +5 days
- Nights above 70°F: +1 days
- Freezing nights: −11 days
- Frost-free season: +5 days
- Muggy days: +3 days
- Summer heat index (Jun–Aug): +1.8°F
- Extreme fire-weather days: +13 days
Changes follow the trend line through every year from 1979 to 2025. Data: NOAA nClimGrid-Daily; humidity from gridMET, adjusted to airport observations.