Monthly outlook for Prospect Heights, IL: average high 65.1°, average low 53.3°. That is 4.1° 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 23 October (72.9°), the coolest 17 October (38.3°).
65.1°/53.3°
Average high / low
+4.1°
Above normal
4 / 5
Wet days / normal
1.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
15 October – 24 October
65.1°
58.9°
+3.5°
25 October – 3 November
64.9°
55.1°
+5.5°
4 November – 13 November
at normal
50°
—
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).
Fri, 1659° / 45°0.03
59 °
Prospect Heights, Friday, 16 October
Light rain. High 59°, low 45°.
Pressure30.03 inHg
Wind15.3 mph NW
Humidity70%
Visibility6.2 mi
Dew point43°
Sat, 1755° / 38°0
55 °
Prospect Heights, Saturday, 17 October
Clear. High 55°, low 38°.
Pressure30.53 inHg
Wind6.3 mph SW
Humidity50%
Visibility6.2 mi
Dew point34°
Sun, 1860° / 42°0
60 °
Prospect Heights, Sunday, 18 October
Clear. High 60°, low 42°.
Pressure30.42 inHg
Wind12.8 mph SW
Humidity54%
Visibility6.2 mi
Dew point40°
Mon, 1961° / 43°0
61 °
Prospect Heights, Monday, 19 October
Overcast. High 61°, low 43°.
Pressure30.33 inHg
Wind8.8 mph SW
Humidity59%
Visibility—
Dew point44°
Tue, 2066° / 48°0
66 °
Prospect Heights, Tuesday, 20 October
Partly cloudy. High 66°, low 48°.
Pressure30.33 inHg
Wind4.6 mph SW
Humidity54%
Visibility—
Dew point46°
Wed, 2168° / 53°0
68 °
Prospect Heights, Wednesday, 21 October
Clear. High 68°, low 53°.
Pressure30.36 inHg
Wind5 mph E
Humidity35%
Visibility—
Dew point37°
Thu, 2271° / 56°0
71 °
Prospect Heights, Thursday, 22 October
Clear. High 71°, low 56°.
Pressure30.24 inHg
Wind7.2 mph SW
Humidity38%
Visibility—
Dew point41°
Fri, 2373° / 62°0
73 °
Prospect Heights, Friday, 23 October
Overcast. High 73°, low 62°.
Pressure30.24 inHg
Wind10.6 mph SE
Humidity33%
Visibility—
Dew point40°
Sat, 2472° / 61°0
72 °
Prospect Heights, Saturday, 24 October
Overcast. High 72°, low 61°.
Pressure30.18 inHg
Wind11.3 mph S
Humidity43%
Visibility—
Dew point44°
Sun, 2562° / 53°0
62 °
Prospect Heights, Sunday, 25 October
Clear. High 62°, low 53°.
Pressure30.50 inHg
Wind9.2 mph N
Humidity36%
Visibility—
Dew point33°
Mon, 2662° / 52°0
62 °
Prospect Heights, Monday, 26 October
Overcast. High 62°, low 52°.
Pressure30.50 inHg
Wind8.8 mph SE
Humidity50%
Visibility—
Dew point40°
Tue, 2772° / 61°0.3
72 °
Prospect Heights, Tuesday, 27 October
Rain. High 72°, low 61°.
Pressure30.09 inHg
Wind13 mph SW
Humidity45%
Visibility—
Dew point48°
Wed, 2861° / 60°0.41
61 °
Prospect Heights, Wednesday, 28 October
Rain. High 61°, low 60°.
Pressure30.00 inHg
Wind10.6 mph SW
Humidity89%
Visibility—
Dew point57°
Thu, 2963° / 60°0.02
63 °
Prospect Heights, Thursday, 29 October
Light rain. High 63°, low 60°.
Pressure29.94 inHg
Wind7.7 mph S
Humidity89%
Visibility—
Dew point58°
Fri, 3069° / 62°0.31
69 °
Prospect Heights, Friday, 30 October
Light rain. High 69°, low 62°.
Pressure29.71 inHg
Wind16 mph SW
Humidity95%
Visibility—
Dew point63°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 3156° / 44°0.14
56 °
Prospect Heights, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high56°
Average low44°
Average precipitation0.14 in
Chance of precipitation40%
Record high72° (1974)
Record low26° (2023)
Sun, 0155° / 43°0.16
55 °
Prospect Heights, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high55°
Average low43°
Average precipitation0.16 in
Chance of precipitation43%
Record high72° (2016)
Record low18° (2019)
Mon, 0254° / 42°0.12
54 °
Prospect Heights, Monday, 2 November
Climate normal for this date — 60-year average.
Average high54°
Average low42°
Average precipitation0.12 in
Chance of precipitation38%
Record high73° (1961)
Record low24° (1991)
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)
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.