Monthly outlook for Cooper, IL: average high 73.8°, average low 55.6°. That is 6° above the climate normal for October. Precipitation is expected on 4 days (about 1.8 inches), against a normal of 5 days and 1.5 inches. The warmest day looks like 15 October (89.7°), the coolest 14 October (46.9°).
73.8°/55.6°
Average high / low
+6°
Above normal
4 / 5
Wet days / normal
1.8 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 October – 17 October
76.3°
64.4°
+6.6°
18 October – 27 October
69.7°
59.6°
+5.6°
28 October – 6 November
at normal
55.8°
—
October records over 66 years
89.1°3 October 2025All-time high
21°22 October 1976All-time low
Climate normals and records are computed from the nearest reference point — Peoria (13 mi).
Fri, 0981° / 52°0
81 °
Cooper, Friday, 9 October
Overcast. High 81°, low 52°.
Pressure30.09 inHg
Wind8.7 mph S
Humidity50%
Visibility6.2 mi
Dew point53°
Sat, 1078° / 61°0
78 °
Cooper, Saturday, 10 October
Overcast. High 78°, low 61°.
Pressure30.09 inHg
Wind5.4 mph S
Humidity53%
Visibility6.2 mi
Dew point57°
Sun, 1174° / 59°0
74 °
Cooper, Sunday, 11 October
Clear. High 74°, low 59°.
Pressure30.00 inHg
Wind3.9 mph E
Humidity59%
Visibility6.2 mi
Dew point56°
Mon, 1284° / 57°0
84 °
Cooper, Monday, 12 October
Clear. High 84°, low 57°.
Pressure29.85 inHg
Wind11.5 mph S
Humidity50%
Visibility—
Dew point57°
Tue, 1372° / 58°0
72 °
Cooper, Tuesday, 13 October
Overcast. High 72°, low 58°.
Pressure29.91 inHg
Wind10 mph N
Humidity62%
Visibility—
Dew point58°
Wed, 1472° / 47°0
72 °
Cooper, Wednesday, 14 October
Partly cloudy. High 72°, low 47°.
Pressure30.06 inHg
Wind17.1 mph SE
Humidity38%
Visibility—
Dew point38°
Thu, 1590° / 66°0.03
90 °
Cooper, Thursday, 15 October
Light rain. High 90°, low 66°.
Pressure29.80 inHg
Wind22.3 mph SW
Humidity40%
Visibility—
Dew point59°
Fri, 1674° / 55°0.3
74 °
Cooper, Friday, 16 October
Rain. High 74°, low 55°.
Pressure30.12 inHg
Wind16.7 mph SW
Humidity35%
Visibility—
Dew point40°
Sat, 1761° / 48°0
61 °
Cooper, Saturday, 17 October
Overcast. High 61°, low 48°.
Pressure30.39 inHg
Wind10.7 mph N
Humidity53%
Visibility—
Dew point41°
Sun, 1866° / 53°0.02
66 °
Cooper, Sunday, 18 October
Light rain. High 66°, low 53°.
Pressure30.24 inHg
Wind5.6 mph E
Humidity53%
Visibility—
Dew point46°
Mon, 1958° / 55°1.33
58 °
Cooper, Monday, 19 October
Rain. High 58°, low 55°.
Pressure30.15 inHg
Wind6.3 mph E
Humidity92%
Visibility—
Dew point55°
Tue, 2063° / 58°0.01
63 °
Cooper, Tuesday, 20 October
Light rain. High 63°, low 58°.
Pressure30.09 inHg
Wind5.5 mph NW
Humidity79%
Visibility—
Dew point56°
Wed, 2169° / 54°0
69 °
Cooper, Wednesday, 21 October
Clear. High 69°, low 54°.
Pressure29.97 inHg
Wind6.9 mph SE
Humidity53%
Visibility—
Dew point49°
Thu, 2278° / 53°0.04
78 °
Cooper, Thursday, 22 October
Light rain. High 78°, low 53°.
Pressure29.68 inHg
Wind17.7 mph S
Humidity45%
Visibility—
Dew point49°
Fri, 2383° / 64°0.05
83 °
Cooper, Friday, 23 October
Light rain. High 83°, low 64°.
Pressure29.83 inHg
Wind15.1 mph S
Humidity51%
Visibility—
Dew point58°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 2459° / 45°0.14
59 °
Cooper, Saturday, 24 October
Climate normal for this date — 60-year average.
Average high59°
Average low45°
Average precipitation0.14 in
Chance of precipitation32%
Record high79° (1963)
Record low24° (1981)
Sun, 2558° / 44°0.11
58 °
Cooper, Sunday, 25 October
Climate normal for this date — 60-year average.
Average high58°
Average low44°
Average precipitation0.11 in
Chance of precipitation27%
Record high75° (2011)
Record low27° (2013)
Mon, 2657° / 43°0.11
57 °
Cooper, Monday, 26 October
Climate normal for this date — 60-year average.
Average high57°
Average low43°
Average precipitation0.11 in
Chance of precipitation32%
Record high80° (1963)
Record low24° (1962)
Tue, 2758° / 43°0.08
58 °
Cooper, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high58°
Average low43°
Average precipitation0.08 in
Chance of precipitation30%
Record high74° (2014)
Record low29° (1997)
Wed, 2857° / 42°0.04
57 °
Cooper, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high57°
Average low42°
Average precipitation0.04 in
Chance of precipitation20%
Record high74° (1999)
Record low25° (1976)
Thu, 2957° / 42°0.08
57 °
Cooper, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high57°
Average low42°
Average precipitation0.08 in
Chance of precipitation25%
Record high78° (2024)
Record low23° (1980)
Fri, 3059° / 43°0.11
59 °
Cooper, Friday, 30 October
Climate normal for this date — 60-year average.
Average high59°
Average low43°
Average precipitation0.11 in
Chance of precipitation28%
Record high79° (1971)
Record low25° (1988)
Sat, 3158° / 43°0.17
58 °
Cooper, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high58°
Average low43°
Average precipitation0.17 in
Chance of precipitation42%
Record high74° (1974)
Record low24° (2019)
Sun, 0157° / 42°0.18
57 °
Cooper, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high57°
Average low42°
Average precipitation0.18 in
Chance of precipitation32%
Record high77° (2016)
Record low22° (2019)
Mon, 0255° / 41°0.08
55 °
Cooper, Monday, 2 November
Climate normal for this date — 60-year average.
Average high55°
Average low41°
Average precipitation0.08 in
Chance of precipitation33%
Record high75° (1961)
Record low23° (1991)
Tue, 0354° / 40°0.09
54 °
Cooper, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high54°
Average low40°
Average precipitation0.09 in
Chance of precipitation23%
Record high74° (1964)
Record low17° (1991)
Wed, 0454° / 41°0.08
54 °
Cooper, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high54°
Average low41°
Average precipitation0.08 in
Chance of precipitation23%
Record high74° (1978)
Record low16° (1991)
Thu, 0553° / 39°0.13
53 °
Cooper, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high53°
Average low39°
Average precipitation0.13 in
Chance of precipitation25%
Record high74° (1978)
Record low19° (1991)
Fri, 0653° / 38°0.09
53 °
Cooper, Friday, 6 November
Climate normal for this date — 60-year average.
Average high53°
Average low38°
Average precipitation0.09 in
Chance of precipitation25%
Record high71° (2020)
Record low24° (1991)
About the monthly outlook
How accurate is a 30-day forecast?
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Cooper, IL are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
What does "above normal" mean?
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
Where do the 66-year records come from?
They are real temperature extremes recorded in Cooper, IL since 1960: the highest and lowest reading for each calendar date, with the year it happened.
How often is it updated?
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.