30-year climate normals
Effingham County Climate and Weather Averages
Hottest month — July
88.5°average daily high. The coldest month is January, averaging a low of 20.1°F.
Effingham County gets 44.01" of precipitation a year and 14.6" of snow, and 34% of it falls in Apr, May, Jun.
Temperature through the year
Each bar spans the average daily low to the average daily high for that month.
| Month | Avg high | Avg low | Precip | Snow |
|---|---|---|---|---|
| January | 37.4° | 20.1° | 2.93" | 5.3" |
| February | 42.5° | 23.4° | 2.44" | 4.6" |
| March | 53.5° | 32.4° | 3.30" | 1.5" |
| April | 65.9° | 42.4° | 4.84" | 0.2" |
| May | 76.2° | 53.6° | 5.27" | 0.0" |
| June | 85.1° | 62.8° | 4.87" | 0.0" |
| July | 88.5° | 66.0° | 4.29" | 0.0" |
| August | 87.2° | 63.7° | 3.19" | 0.0" |
| September | 81.2° | 55.5° | 2.89" | 0.0" |
| October | 68.8° | 44.1° | 3.49" | 0.0" |
| November | 54.0° | 33.7° | 3.73" | 0.6" |
| December | 42.2° | 25.4° | 2.77" | 2.4" |
Rainfall by month
Precipitation is spread fairly evenly through the year here, with 34% falling in the wettest three months (Apr, May, Jun).
What this climate costs you
Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.
These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in Effingham County, where electricity is one line of eight.
Common questions
What is the weather like in Effingham County?
Effingham County averages a high of 88.5°F in July and a low of 20.1°F in January. Annual precipitation is 44.01 inches, including 14.6 inches of snow.
When is the rainy season in Effingham County?
The wettest stretch is Apr, May, Jun, which accounts for 34% of the year's precipitation. Precipitation is relatively evenly distributed across the year.
How hot does it get in Effingham County?
The average daily high in July, the hottest month, is 88.5°F. That drives 1,298 cooling degree days a year, which is what your air conditioning has to work against.
Does it snow in Effingham County?
Yes. Effingham County averages 14.6 inches of snow a year.
Sources
- Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station EFFINGHAM 3SW, IL US (USC00112687), 5.1 miles from the county centroid.
- Heating and cooling degree days — NOAA, same station and period.
- Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, Illinois residential average.
- Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.