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What is Harristown, IL, Weather Like in October?
During the month of October, Harristown, IL,
has an average daytime high temperature of 66°F and an average overnight low temperature dropping to 46°F.
Around 3.41 inches of precipitation is received during the month,
with about 34.83 inches falling in a typical year.
As you might expect, snow is not common in the month of October.
Annually, Harristown receives around 9.70 inches of snow.
October 2025: Actual vs. Average Temperatures
Showing temperatures through today (October 19, 2025)
Actual High
Average High
Actual Low
Average Low
Actual data from: PWS_MOSERFARM
Harristown, IL Daily Weather Averages for October
Recorded at Decatur Wtp
(usc00112193),
7.3 miles
ESE of
Harristown, IL
| Day | Avg Temps (°F) | Precip (in) | Snow (in) | Degree Days (°F) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Low | High | Mean | Month | Year | Month | Year | Heat | Cool | |
| 10/1 | 51 F | 72 F | 62 F | 0.09" | 31.51" | 0.00" | 9.70" | 5.2 F | 1.9 F |
| 10/2 | 51 F | 72 F | 61 F | 0.19" | 31.61" | 0.00" | 9.70" | 5.5 F | 1.7 F |
| 10/3 | 50 F | 71 F | 61 F | 0.29" | 31.71" | 0.00" | 9.70" | 5.7 F | 1.6 F |
| 10/4 | 50 F | 71 F | 61 F | 0.39" | 31.81" | 0.00" | 9.70" | 6 F | 1.5 F |
| 10/5 | 50 F | 71 F | 60 F | 0.50" | 31.92" | 0.00" | 9.70" | 6.3 F | 1.4 F |
| 10/6 | 49 F | 70 F | 60 F | 0.60" | 32.02" | 0.00" | 9.70" | 6.6 F | 1.3 F |
| 10/7 | 49 F | 70 F | 59 F | 0.71" | 32.13" | 0.00" | 9.70" | 7 F | 1.2 F |
| 10/8 | 49 F | 69 F | 59 F | 0.81" | 32.23" | 0.00" | 9.70" | 7.3 F | 1.1 F |
| 10/9 | 48 F | 69 F | 59 F | 0.92" | 32.34" | 0.00" | 9.70" | 7.6 F | 1 F |
| 10/10 | 48 F | 68 F | 58 F | 1.03" | 32.45" | 0.00" | 9.70" | 7.9 F | 1 F |
| 10/11 | 48 F | 68 F | 58 F | 1.13" | 32.55" | 0.00" | 9.70" | 8.2 F | 0.9 F |
| 10/12 | 47 F | 67 F | 57 F | 1.24" | 32.66" | 0.00" | 9.70" | 8.5 F | 0.8 F |
| 10/13 | 47 F | 67 F | 57 F | 1.35" | 32.77" | 0.00" | 9.70" | 8.8 F | 0.7 F |
| 10/14 | 46 F | 66 F | 56 F | 1.46" | 32.88" | 0.00" | 9.70" | 9.2 F | 0.6 F |
| 10/15 | 46 F | 66 F | 56 F | 1.57" | 32.99" | 0.00" | 9.70" | 9.5 F | 0.5 F |
| 10/16 | 46 F | 65 F | 56 F | 1.69" | 33.11" | 0.00" | 9.70" | 9.9 F | 0.4 F |
| 10/17 | 45 F | 65 F | 55 F | 1.81" | 33.23" | 0.00" | 9.70" | 10.2 F | 0.4 F |
| 10/18 | 45 F | 65 F | 55 F | 1.93" | 33.35" | 0.00" | 9.70" | 10.6 F | 0.4 F |
| 10/19 | 45 F | 64 F | 54 F | 2.05" | 33.47" | 0.00" | 9.70" | 11 F | 0.4 F |
| 10/20 | 44 F | 64 F | 54 F | 2.17" | 33.59" | 0.00" | 9.70" | 11.4 F | 0.3 F |
| 10/21 | 44 F | 63 F | 54 F | 2.28" | 33.70" | 0.00" | 9.70" | 11.8 F | 0.3 F |
| 10/22 | 44 F | 63 F | 53 F | 2.40" | 33.82" | 0.00" | 9.70" | 12.3 F | 0.3 F |
| 10/23 | 43 F | 62 F | 53 F | 2.51" | 33.93" | 0.00" | 9.70" | 12.7 F | 0.3 F |
| 10/24 | 43 F | 62 F | 52 F | 2.62" | 34.04" | 0.00" | 9.70" | 13.1 F | 0.2 F |
| 10/25 | 43 F | 61 F | 52 F | 2.74" | 34.16" | 0.00" | 9.70" | 13.5 F | 0.2 F |
| 10/26 | 42 F | 61 F | 51 F | 2.85" | 34.27" | 0.00" | 9.70" | 13.9 F | 0.2 F |
| 10/27 | 42 F | 60 F | 51 F | 2.96" | 34.38" | 0.00" | 9.70" | 14.3 F | 0.2 F |
| 10/28 | 41 F | 60 F | 50 F | 3.08" | 34.50" | 0.00" | 9.70" | 14.8 F | 0.2 F |
| 10/29 | 41 F | 59 F | 50 F | 3.19" | 34.61" | 0.00" | 9.70" | 15.2 F | 0.2 F |
| 10/30 | 41 F | 58 F | 50 F | 3.30" | 34.72" | 0.00" | 9.70" | 15.6 F | 0.1 F |
| 10/31 | 40 F | 58 F | 49 F | 3.41" | 34.83" | 0.00" | 9.70" | 16.1 F | 0.1 F |
Weather data provided by Xweather
