Illinois · county areal climate 1951–2025
Mason County, IL
A 53.1°F / 37.5" normal · 2025 ran +0.7°F vs normal.
2026 so far · through Jul 9: This area is running
+2.1°F (51.7°F) vs the 1996–2025 to-date normal — the
9th warmest start of 76 years. Precipitation
124% of normal.
U.S. year-to-date → Normal (1996–2025)
53.1°F
annual mean · 37.5" precipitation
2025 vs Normal
+0.7°F
53.8°F · 26.6" (71% of normal)
Warmest Year
55.7°F
2012 · coldest 49.7°F (1978)
Wettest Year
57.4in
2009 · driest 22.6" (1988)
Hottest Day
104.7°F
Jul 14 · 1954
Coldest Day
-21.9°F
Jan 5 · 1999
Biggest Rain Day
3.57in
Dec 3 · 1982
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.