Monthly outlook for Prospect Heights, IL: average high 59.4°, average low 45.5°. That is 1.9° above the climate normal for October. Precipitation is expected on 4 days (about 1.0 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 21 October (71.8°), the coolest 30 October (34.2°).
59.4°/45.5°
Average high / low
+1.9°
Above normal
4 / 5
Wet days / normal
1.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
20 October – 29 October
61.8°
57.1°
+2.6°
30 October – 8 November
55.4°
53.2°
+1.3°
9 November – 18 November
at normal
47.7°
—
October records over 66 years
88.2°3 October 2025All-time high
26.2°31 October 2023All-time low
Climate normals and records are computed from the nearest reference point — Park Ridge (8 mi).
Wed, 2172° / 43°0
72 °
Prospect Heights, Wednesday, 21 October
Clear. High 72°, low 43°.
Pressure30.27 inHg
Wind4.3 mph SW
Humidity55%
Visibility6.2 mi
Dew point49°
Thu, 2268° / 48°0
68 °
Prospect Heights, Thursday, 22 October
Clear. High 68°, low 48°.
Pressure30.27 inHg
Wind3.3 mph E
Humidity66%
Visibility6.2 mi
Dew point56°
Fri, 2367° / 54°0
67 °
Prospect Heights, Friday, 23 October
Clear. High 67°, low 54°.
Pressure30.36 inHg
Wind3.5 mph SE
Humidity68%
Visibility6.2 mi
Dew point54°
Sat, 2466° / 49°0
66 °
Prospect Heights, Saturday, 24 October
Overcast. High 66°, low 49°.
Pressure30.39 inHg
Wind7.5 mph S
Humidity66%
Visibility6.2 mi
Dew point51°
Sun, 2569° / 53°0
69 °
Prospect Heights, Sunday, 25 October
Overcast. High 69°, low 53°.
Pressure30.33 inHg
Wind6.9 mph S
Humidity61%
Visibility—
Dew point52°
Mon, 2661° / 52°0.01
61 °
Prospect Heights, Monday, 26 October
Light rain. High 61°, low 52°.
Pressure30.18 inHg
Wind11.1 mph N
Humidity64%
Visibility—
Dew point48°
Tue, 2751° / 48°0.29
51 °
Prospect Heights, Tuesday, 27 October
Light rain. High 51°, low 48°.
Pressure30.30 inHg
Wind11.2 mph NE
Humidity86%
Visibility—
Dew point44°
Wed, 2850° / 42°0.55
50 °
Prospect Heights, Wednesday, 28 October
Rain. High 50°, low 42°.
Pressure30.00 inHg
Wind13.7 mph NW
Humidity89%
Visibility—
Dew point44°
Thu, 2947° / 38°0
47 °
Prospect Heights, Thursday, 29 October
Clear. High 47°, low 38°.
Pressure30.21 inHg
Wind10.7 mph NW
Humidity42%
Visibility—
Dew point23°
Fri, 3050° / 34°0
50 °
Prospect Heights, Friday, 30 October
Clear. High 50°, low 34°.
Pressure30.27 inHg
Wind7.9 mph S
Humidity34%
Visibility—
Dew point18°
Sat, 3154° / 44°0
54 °
Prospect Heights, Saturday, 31 October
Overcast. High 54°, low 44°.
Pressure29.97 inHg
Wind12.7 mph S
Humidity32%
Visibility—
Dew point22°
Sun, 0163° / 51°0.08
63 °
Prospect Heights, Sunday, 1 November
Light rain. High 63°, low 51°.
Pressure29.80 inHg
Wind14.1 mph S
Humidity82%
Visibility—
Dew point53°
Mon, 0262° / 45°0.09
62 °
Prospect Heights, Monday, 2 November
Light rain. High 62°, low 45°.
Pressure30.09 inHg
Wind14.2 mph SW
Humidity40%
Visibility—
Dew point32°
Tue, 0352° / 39°0
52 °
Prospect Heights, Tuesday, 3 November
Clear. High 52°, low 39°.
Pressure30.47 inHg
Wind6.6 mph NW
Humidity26%
Visibility—
Dew point16°
Wed, 0452° / 45°0
52 °
Prospect Heights, Wednesday, 4 November
Overcast. High 52°, low 45°.
Pressure30.27 inHg
Wind10.2 mph SW
Humidity39%
Visibility—
Dew point27°
From day 17 onward the outlook is built from 60-year climate statistics
Thu, 0553° / 41°0.13
53 °
Prospect Heights, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high53°
Average low41°
Average precipitation0.13 in
Chance of precipitation33%
Record high73° (1978)
Record low20° (1991)
Fri, 0652° / 39°0.07
52 °
Prospect Heights, Friday, 6 November
Climate normal for this date — 60-year average.
Average high52°
Average low39°
Average precipitation0.07 in
Chance of precipitation30%
Record high71° (1975)
Record low24° (1991)
Sat, 0751° / 39°0.05
51 °
Prospect Heights, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high51°
Average low39°
Average precipitation0.05 in
Chance of precipitation22%
Record high69° (2020)
Record low20° (1991)
Sun, 0851° / 39°0.05
51 °
Prospect Heights, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high51°
Average low39°
Average precipitation0.05 in
Chance of precipitation18%
Record high74° (2020)
Record low17° (1991)
Mon, 0951° / 39°0.12
51 °
Prospect Heights, Monday, 9 November
Climate normal for this date — 60-year average.
Average high51°
Average low39°
Average precipitation0.12 in
Chance of precipitation38%
Record high72° (2020)
Record low21° (1991)
Tue, 1050° / 39°0.11
50 °
Prospect Heights, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high50°
Average low39°
Average precipitation0.11 in
Chance of precipitation33%
Record high73° (2020)
Record low18° (2017)
Wed, 1148° / 36°0.08
48 °
Prospect Heights, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high48°
Average low36°
Average precipitation0.08 in
Chance of precipitation32%
Record high69° (1964)
Record low15° (2019)
Thu, 1246° / 35°0.06
46 °
Prospect Heights, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high46°
Average low35°
Average precipitation0.06 in
Chance of precipitation23%
Record high66° (1964)
Record low3° (2019)
Fri, 1346° / 35°0.05
46 °
Prospect Heights, Friday, 13 November
Climate normal for this date — 60-year average.
Average high46°
Average low35°
Average precipitation0.05 in
Chance of precipitation18%
Record high68° (1999)
Record low1° (2019)
Sat, 1447° / 35°0.07
47 °
Prospect Heights, Saturday, 14 November
Climate normal for this date — 60-year average.
Average high47°
Average low35°
Average precipitation0.07 in
Chance of precipitation33%
Record high68° (1971)
Record low15° (1986)
Sun, 1547° / 36°0.09
47 °
Prospect Heights, Sunday, 15 November
Climate normal for this date — 60-year average.
Average high47°
Average low36°
Average precipitation0.09 in
Chance of precipitation28%
Record high69° (2025)
Record low19° (2019)
Mon, 1647° / 35°0.05
47 °
Prospect Heights, Monday, 16 November
Climate normal for this date — 60-year average.
Average high47°
Average low35°
Average precipitation0.05 in
Chance of precipitation23%
Record high62° (2023)
Record low22° (1997)
Tue, 1747° / 36°0.09
47 °
Prospect Heights, Tuesday, 17 November
Climate normal for this date — 60-year average.
Average high47°
Average low36°
Average precipitation0.09 in
Chance of precipitation32%
Record high68° (2016)
Record low16° (2014)
Wed, 1847° / 36°0.13
47 °
Prospect Heights, Wednesday, 18 November
Climate normal for this date — 60-year average.
Average high47°
Average low36°
Average precipitation0.13 in
Chance of precipitation28%
Record high66° (2016)
Record low12° (2014)
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 Prospect Heights, 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 Prospect Heights, 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.