Monthly outlook for Cooper, IL: average high 72.3°, average low 54°. That is 5.2° above the climate normal for October. Precipitation is expected on 4 days (about 1.6 inches), against a normal of 5 days and 1.5 inches. The warmest day looks like 15 October (89.4°), the coolest 18 October (41.5°).
72.3°/54°
Average high / low
+5.2°
Above normal
4 / 5
Wet days / normal
1.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 October – 17 October
76.4°
64.4°
+6.7°
18 October – 27 October
65.5°
59.6°
+3.2°
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, 1079° / 60°0
79 °
Cooper, Saturday, 10 October
Overcast. High 79°, low 60°.
Pressure30.09 inHg
Wind6 mph S
Humidity57%
Visibility6.2 mi
Dew point57°
Sun, 1174° / 57°0
74 °
Cooper, Sunday, 11 October
Clear. High 74°, low 57°.
Pressure29.94 inHg
Wind3.2 mph N
Humidity65%
Visibility6.2 mi
Dew point58°
Mon, 1283° / 60°0
83 °
Cooper, Monday, 12 October
Overcast. High 83°, low 60°.
Pressure29.88 inHg
Wind8.4 mph SW
Humidity56%
Visibility6.2 mi
Dew point61°
Tue, 1382° / 67°0
82 °
Cooper, Tuesday, 13 October
Partly cloudy. High 82°, low 67°.
Pressure29.85 inHg
Wind9.8 mph NE
Humidity61%
Visibility—
Dew point65°
Wed, 1474° / 57°0.04
74 °
Cooper, Wednesday, 14 October
Light rain. High 74°, low 57°.
Pressure29.97 inHg
Wind14.9 mph SE
Humidity72%
Visibility—
Dew point49°
Thu, 1589° / 74°0.31
89 °
Cooper, Thursday, 15 October
Rain. High 89°, low 74°.
Pressure29.85 inHg
Wind19.6 mph SW
Humidity44%
Visibility—
Dew point63°
Fri, 1669° / 52°1.11
69 °
Cooper, Friday, 16 October
Heavy rain. High 69°, low 52°.
Pressure30.27 inHg
Wind14 mph N
Humidity67%
Visibility—
Dew point49°
Sat, 1757° / 43°0
57 °
Cooper, Saturday, 17 October
Mostly clear. High 57°, low 43°.
Pressure30.62 inHg
Wind13.6 mph NE
Humidity52%
Visibility—
Dew point37°
Sun, 1858° / 42°0
58 °
Cooper, Sunday, 18 October
Overcast. High 58°, low 42°.
Pressure30.45 inHg
Wind8.2 mph SE
Humidity39%
Visibility—
Dew point30°
Mon, 1972° / 49°0.04
72 °
Cooper, Monday, 19 October
Light rain. High 72°, low 49°.
Pressure30.15 inHg
Wind14.8 mph SW
Humidity60%
Visibility—
Dew point51°
Tue, 2074° / 60°0.01
74 °
Cooper, Tuesday, 20 October
Light rain. High 74°, low 60°.
Pressure30.12 inHg
Wind11.9 mph SW
Humidity56%
Visibility—
Dew point54°
Wed, 2170° / 53°0
70 °
Cooper, Wednesday, 21 October
Clear. High 70°, low 53°.
Pressure30.09 inHg
Wind7.7 mph W
Humidity35%
Visibility—
Dew point38°
Thu, 2260° / 50°0.13
60 °
Cooper, Thursday, 22 October
Light rain. High 60°, low 50°.
Pressure29.94 inHg
Wind17.2 mph W
Humidity80%
Visibility—
Dew point49°
Fri, 2359° / 42°0
59 °
Cooper, Friday, 23 October
Clear. High 59°, low 42°.
Pressure30.18 inHg
Wind13.3 mph W
Humidity46%
Visibility—
Dew point34°
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.