Monthly outlook for Prospect Heights, IL: average high 65.7°, average low 51.6°. That is 5° above the climate normal for October. Precipitation is expected on 2 days (about 0.1 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 1 November (76.4°), the coolest 18 October (41.5°).
65.7°/51.6°
Average high / low
+5°
Above normal
2 / 5
Wet days / normal
0.1 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
18 October – 27 October
63.3°
57.8°
+3.1°
28 October – 6 November
69.8°
54°
+8.8°
7 November – 16 November
at normal
48.4°
—
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).
Mon, 1965° / 46°0
65 °
Prospect Heights, Monday, 19 October
Clear. High 65°, low 46°.
Pressure30.39 inHg
Wind3.7 mph SW
Humidity61%
Visibility6.2 mi
Dew point47°
Tue, 2064° / 44°0
64 °
Prospect Heights, Tuesday, 20 October
Mostly clear. High 64°, low 44°.
Pressure30.39 inHg
Wind4 mph SE
Humidity68%
Visibility6.2 mi
Dew point52°
Wed, 2165° / 45°0
65 °
Prospect Heights, Wednesday, 21 October
Clear. High 65°, low 45°.
Pressure30.30 inHg
Wind4.1 mph SW
Humidity57%
Visibility6.2 mi
Dew point49°
Thu, 2267° / 50°0
67 °
Prospect Heights, Thursday, 22 October
Partly cloudy. High 67°, low 50°.
Pressure30.30 inHg
Wind6.9 mph NE
Humidity64%
Visibility—
Dew point53°
Fri, 2360° / 50°0
60 °
Prospect Heights, Friday, 23 October
Clear. High 60°, low 50°.
Pressure30.39 inHg
Wind7.4 mph E
Humidity64%
Visibility—
Dew point47°
Sat, 2473° / 60°0
73 °
Prospect Heights, Saturday, 24 October
Overcast. High 73°, low 60°.
Pressure30.21 inHg
Wind12.3 mph S
Humidity31%
Visibility—
Dew point37°
Sun, 2563° / 49°0
63 °
Prospect Heights, Sunday, 25 October
Overcast. High 63°, low 49°.
Pressure30.42 inHg
Wind11.2 mph NW
Humidity25%
Visibility—
Dew point21°
Mon, 2658° / 45°0
58 °
Prospect Heights, Monday, 26 October
Partly cloudy. High 58°, low 45°.
Pressure30.36 inHg
Wind8.5 mph SW
Humidity19%
Visibility—
Dew point14°
Tue, 2754° / 51°0.07
54 °
Prospect Heights, Tuesday, 27 October
Light rain. High 54°, low 51°.
Pressure30.18 inHg
Wind8.5 mph SW
Humidity89%
Visibility—
Dew point49°
Wed, 2866° / 54°0
66 °
Prospect Heights, Wednesday, 28 October
Overcast. High 66°, low 54°.
Pressure29.94 inHg
Wind8.9 mph SW
Humidity51%
Visibility—
Dew point46°
Thu, 2968° / 59°0
68 °
Prospect Heights, Thursday, 29 October
Overcast. High 68°, low 59°.
Pressure29.77 inHg
Wind8.5 mph SW
Humidity57%
Visibility—
Dew point50°
Fri, 3071° / 54°0
71 °
Prospect Heights, Friday, 30 October
Light rain. High 71°, low 54°.
Pressure29.77 inHg
Wind13.3 mph SW
Humidity54%
Visibility—
Dew point49°
Sat, 3173° / 61°0.04
73 °
Prospect Heights, Saturday, 31 October
Light rain. High 73°, low 61°.
Pressure29.71 inHg
Wind12.8 mph SW
Humidity64%
Visibility—
Dew point57°
Sun, 0176° / 64°0
76 °
Prospect Heights, Sunday, 1 November
Overcast. High 76°, low 64°.
Pressure29.88 inHg
Wind11.8 mph SW
Humidity56%
Visibility—
Dew point56°
Mon, 0264° / 53°0
64 °
Prospect Heights, Monday, 2 November
Clear. High 64°, low 53°.
Pressure30.30 inHg
Wind12.3 mph NE
Humidity48%
Visibility—
Dew point40°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0353° / 41°0.06
53 °
Prospect Heights, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high53°
Average low41°
Average precipitation0.06 in
Chance of precipitation22%
Record high71° (1987)
Record low18° (1991)
Wed, 0452° / 42°0.09
52 °
Prospect Heights, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high52°
Average low42°
Average precipitation0.09 in
Chance of precipitation27%
Record high70° (2022)
Record low17° (1991)
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)
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.