St. Elmo, IL

Climate overview — based on NOAA 1991-2020 normals from BROWNSTOWN 4 SW, IL US.

Dfa Hot-summer humid continental climate 7b USDA hardiness Zone 7b

Year-round temperatures (°F)

20° 40° 60° 80° J F M A M J J A S O N D
Avg high Avg low

Climate summary

St. Elmo has an annual average temperature of 54.6°F with about 41.2 inches of precipitation per year. The warmest month is July (average high 86.7°F), and the coldest is January (average low 21.3°F). May is typically the wettest month (5.34 in) and December the driest (2.15 in).

Pleasant months
2 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
47.6°F
warmest to coldest month
Heating need
4,776
Cooling need
1,023

Best time to visit St. Elmo

Full guide →

Climate change signal

All-time records →

0 of 366 (0%) of St. Elmo's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1990s
151
2000s
215

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 37.0°F 21.3°F 29.2°F 2.82 in 10
February 42.1°F 25.3°F 33.7°F 2.41 in 8
March 52.4°F 34.7°F 43.6°F 3.17 in 9
April 64.9°F 45.4°F 55.2°F 4.39 in 10
May 74.7°F 55.1°F 64.9°F 5.34 in 12
June 83.6°F 65.1°F 74.3°F 4.13 in 9
July 86.7°F 67.0°F 76.8°F 3.74 in 8
August 85.5°F 64.1°F 74.8°F 3.15 in 8
September 80.0°F 56.4°F 68.2°F 3.38 in 7
October 66.6°F 44.9°F 55.8°F 2.89 in 7
November 52.8°F 35.5°F 44.2°F 3.63 in 9
December 41.6°F 26.7°F 34.2°F 2.15 in 9

Climate twins of St. Elmo

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

Compare St. Elmo to another city