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What is Merriam, IL, Weather Like in October?
During the month of October, Merriam, IL,
has an average daytime high temperature of 71°F and an average overnight low temperature dropping to 47°F.
Around 3.73 inches of precipitation is received during the month,
with about 38.88 inches falling in a typical year.
Snow is not common in Merriam, IL.
October 2025: Actual vs. Average Temperatures
Showing temperatures through today (October 21, 2025)
Actual High
Average High
Actual Low
Average Low
Month Summary
Average High: 78.9 F
(+5.8 vs avg)
Average Low: 52.4 F
(+3.4 vs avg)
This month was significantly warmer than average.
Actual data from: KFWC
Merriam, IL Daily Weather Averages for October
Recorded at Fairfield Radio Wfiw
(usc00112931),
2.9 miles
WNW of
Merriam, IL
| Day | Avg Temps (°F) | Precip (in) | Snow (in) | Degree Days (°F) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Low | High | Mean | Month | Year | Month | Year | Heat | Cool | |
| 10/1 | 52 F | 77 F | 65 F | 0.12" | 35.27" | N/A | N/A | 3.6 F | 3.4 F |
| 10/2 | 52 F | 77 F | 64 F | 0.23" | 35.38" | N/A | N/A | 3.8 F | 3.2 F |
| 10/3 | 52 F | 76 F | 64 F | 0.35" | 35.50" | N/A | N/A | 4 F | 3 F |
| 10/4 | 51 F | 76 F | 64 F | 0.47" | 35.62" | N/A | N/A | 4.3 F | 2.8 F |
| 10/5 | 51 F | 75 F | 63 F | 0.58" | 35.73" | N/A | N/A | 4.5 F | 2.7 F |
| 10/6 | 51 F | 75 F | 63 F | 0.70" | 35.85" | N/A | N/A | 4.7 F | 2.5 F |
| 10/7 | 50 F | 75 F | 62 F | 0.82" | 35.97" | N/A | N/A | 5 F | 2.4 F |
| 10/8 | 50 F | 74 F | 62 F | 0.94" | 36.09" | N/A | N/A | 5.2 F | 2.2 F |
| 10/9 | 50 F | 74 F | 62 F | 1.05" | 36.20" | N/A | N/A | 5.5 F | 2.1 F |
| 10/10 | 49 F | 73 F | 61 F | 1.16" | 36.31" | N/A | N/A | 5.7 F | 2 F |
| 10/11 | 49 F | 73 F | 61 F | 1.27" | 36.42" | N/A | N/A | 6 F | 1.8 F |
| 10/12 | 48 F | 72 F | 60 F | 1.39" | 36.54" | N/A | N/A | 6.2 F | 1.6 F |
| 10/13 | 48 F | 72 F | 60 F | 1.51" | 36.66" | N/A | N/A | 6.4 F | 1.5 F |
| 10/14 | 48 F | 72 F | 60 F | 1.63" | 36.78" | N/A | N/A | 6.7 F | 1.3 F |
| 10/15 | 47 F | 71 F | 59 F | 1.75" | 36.90" | N/A | N/A | 6.9 F | 1.2 F |
| 10/16 | 47 F | 71 F | 59 F | 1.87" | 37.02" | N/A | N/A | 7.2 F | 1.1 F |
| 10/17 | 47 F | 70 F | 58 F | 1.99" | 37.14" | N/A | N/A | 7.6 F | 1 F |
| 10/18 | 46 F | 70 F | 58 F | 2.12" | 37.27" | N/A | N/A | 7.9 F | 0.9 F |
| 10/19 | 46 F | 69 F | 58 F | 2.25" | 37.40" | N/A | N/A | 8.2 F | 0.8 F |
| 10/20 | 46 F | 69 F | 57 F | 2.38" | 37.53" | N/A | N/A | 8.6 F | 0.8 F |
| 10/21 | 45 F | 68 F | 57 F | 2.50" | 37.65" | N/A | N/A | 9 F | 0.7 F |
| 10/22 | 45 F | 68 F | 56 F | 2.63" | 37.78" | N/A | N/A | 9.4 F | 0.7 F |
| 10/23 | 45 F | 67 F | 56 F | 2.76" | 37.91" | N/A | N/A | 9.7 F | 0.7 F |
| 10/24 | 44 F | 67 F | 56 F | 2.88" | 38.03" | N/A | N/A | 10.1 F | 0.6 F |
| 10/25 | 44 F | 66 F | 55 F | 3.00" | 38.15" | N/A | N/A | 10.5 F | 0.6 F |
| 10/26 | 43 F | 66 F | 55 F | 3.12" | 38.27" | N/A | N/A | 10.9 F | 0.5 F |
| 10/27 | 43 F | 65 F | 54 F | 3.24" | 38.39" | N/A | N/A | 11.3 F | 0.5 F |
| 10/28 | 43 F | 65 F | 54 F | 3.36" | 38.51" | N/A | N/A | 11.7 F | 0.5 F |
| 10/29 | 42 F | 64 F | 53 F | 3.48" | 38.63" | N/A | N/A | 12.1 F | 0.4 F |
| 10/30 | 42 F | 64 F | 53 F | 3.61" | 38.76" | N/A | N/A | 12.5 F | 0.4 F |
| 10/31 | 42 F | 63 F | 53 F | 3.73" | 38.88" | N/A | N/A | 12.9 F | 0.4 F |
