Mount Vernon, IL Weather & Climate Normals
What a normal year in Mount Vernon actually looks like
On the 30-year record NOAA keeps for Mount Vernon, IL, the comfort score comes out to 48/100, strongly seasonal: Comfortable weather is limited to a shorter window; summers, winters, or precipitation swing wide. Only 5 months a year land in the 55–75°F range this site treats as mild.
How much Mount Vernon's weather actually swings
Average temperatures in Mount Vernon run from 30°F in Jan up to 77°F in Jul, a 46.4°F seasonal swing, one of the widest gaps in this dataset.
Mount Vernon, month by month
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| Jan | 39°F | 22°F | 2.6in | 3.2in |
| Feb | 44°F | 25°F | 2.62in | 3.1in |
| Mar | 54°F | 34°F | 4in | 1in |
| Apr | 65°F | 44°F | 4.96in | 0in |
| May | 74°F | 55°F | 5.06in | 0in |
| Jun | 82°F | 64°F | 4.84in | 0in |
| Jul | 86°F | 67°F | 3.78in | 0in |
| Aug | 85°F | 65°F | 3.33in | 0in |
| Sep | 79°F | 57°F | 3.37in | 0in |
| Oct | 68°F | 45°F | 3.53in | 0.2in |
| Nov | 54°F | 34°F | 3.99in | 0.4in |
| Dec | 43°F | 26°F | 2.89in | 2.5in |
If you're timing a visit, May, Jun, Aug, Sep, and Oct are Mount Vernon's mildest stretch; if you're moving there, you should plan around Jul's heat and Jan's cold instead.
How wet Mount Vernon actually gets
Over a typical year, Mount Vernon sees about 44.97in of precipitation a year across roughly 115 days with measurable rain or snow, with 10.4in of snow a year.
Mount Vernon against the rest of the country
Out of 4876 cities scored here, Mount Vernon comes in at 2401; within IL alone it ranks 54 of 330. Population is about 14,162.
Checking the actual forecast
These figures come from Mt Vernon 3 Ne, IL US, the NOAA station 4.2 miles from Mount Vernon, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why some cities show no snow or rain figure · What a 30-year climate normal actually is