Sullivan, Illinois Climate
United States
Pop. 4,494 Elev. 207 m / 679 ft
TZ: America/Chicago (UTC-5) ·
Sullivan has warm summers with average highs of 87°F (31°C) in July, and frigid winters averaging 17°F (-8°C) in January. Humidity pushes the summer feels-like temperature to 101°F (38°C), while wind chill can drive winter lows to 9°F (-13°C). Rain falls on about 51 days per year (35.3 in / 896 mm total), with snow on 7 days and 31 in (786 mm) of annual accumulation. The city averages 130 sunny days per year and around 37 thunderstorm days.
| Temperature | 87°F (30°C) high | 17°F (-8°C) low |
| Feels like | 101°F (39°C) high | 9°F (-13°C) low |
| Rain | 51 days | 35.3 in (896 mm) /yr |
| Snow | 7 days | 31.0 in (786 mm) /yr |
| Sky | 130 sunny | 37 stormy |
| Wind | 2.7 mph (1.2 m/s) avg |
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Explore on the MapMonthly Climate Chart
Best months to visit: Mar, Aug, Sep, Oct
Sky & Air by Month
Cloud cover (%)
50
Jan 61
Feb 54
Mar 66
Apr 63
May 58
Jun 61
Jul 44
Aug 32
Sep 44
Oct 51
Nov 67
Dec Humidity (%)
71
Jan 66
Feb 56
Mar 62
Apr 65
May 72
Jun 78
Jul 71
Aug 63
Sep 65
Oct 68
Nov 78
Dec Weather Days by Month
Cities with Similar Climate
Find similar cities on the map →Nearby Cities
Nearby
Commercial airport 21 mi Decatur Airport (DEC)
Ski resort 153 mi
National park 79 mi Shakamak State Park
Mountain peak
(4,938 ft) 383 mi Gregory Bald
Hospital 17 mi HSHS Good Shepherd Hospital
Hiking trail 27 mi Bluestem Loop
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Monthly Weather Data
↑ See chart| Month | Avg High | Avg Low | Rainfall | Snowfall | Sunny Days |
|---|---|---|---|---|---|
| January | 32°F 0°C | 17°F -8°C | 0.6 in 16 mm | 9.9 in253 mm | 14 |
| February | 41°F 5°C | 25°F -4°C | 0.7 in 19 mm | 5.8 in147 mm | 8 |
| March | 62°F 17°C | 40°F 4°C | 3.0 in 77 mm | 1.0 in26 mm | 11 |
| April | 68°F 20°C | 47°F 8°C | 5.5 in 140 mm | — | 5 |
| May | 73°F 23°C | 55°F 13°C | 3.9 in 99 mm | — | 6 |
| June | 84°F 29°C | 68°F 20°C | 6.5 in 166 mm | — | 8 |
| July | 87°F 30°C | 72°F 22°C | 6.3 in 161 mm | — | 7 |
| August | 83°F 28°C | 65°F 18°C | 1.0 in 25 mm | — | 16 |
| September | 82°F 28°C | 58°F 14°C | 2.1 in 54 mm | — | 20 |
| October | 70°F 21°C | 50°F 10°C | 2.4 in 60 mm | — | 18 |
| November | 54°F 12°C | 37°F 3°C | 2.2 in 55 mm | 6.4 in163 mm | 11 |
| December | 41°F 5°C | 25°F -4°C | 0.9 in 23 mm | 7.8 in199 mm | 6 |
Weather Days by Month
↑ See chart| Month | Sunny Days | Storm Days |
|---|---|---|
| January | 14 | 0 |
| February | 8 | 0 |
| March | 11 | 2 |
| April | 5 | 6 |
| May | 6 | 4 |
| June | 8 | 8 |
| July | 7 | 8 |
| August | 16 | 2 |
| September | 20 | 3 |
| October | 18 | 2 |
| November | 11 | 1 |
| December | 6 | 1 |