Illinois · county areal climate 1951–2025
Jefferson County, IL
A 56.0°F / 45.2" normal · 2025 ran +0.8°F vs normal.
2026 so far · through Aug 29: This area is running
+2.3°F (60.0°F) vs the 1996–2025 to-date normal — the
3rd warmest start of 76 years. Precipitation
72% of normal.
U.S. year-to-date → Normal (1996–2025)
56.0°F
annual mean · 45.2" precipitation
2025 vs Normal
+0.8°F
56.8°F · 36.4" (80% of normal)
Warmest Year
58.6°F
2024 · coldest 52.5°F (1979)
Wettest Year
63.8in
2011 · driest 27.0" (1953)
Hottest Day
105.7°F
Jun 29 · 2012
Coldest Day
-20.3°F
Jan 17 · 1977
Biggest Rain Day
4.99in
Apr 29 · 1996
Record
1951–2025
75 complete years · NOAA nClimGrid
—— normal temperature (°F) · ▮ normal precipitation (in) · 1996–2025
Areal
nClimGrid averages (NOAA/NCEI) over the whole area — an average across the region, not a single station. Separate from the
station records.