Monthly outlook for Prospect Heights, IL: average high 63.9°, average low 51°. That is 3.4° above the climate normal for October. Precipitation is expected on 2 days (about 0.8 inches), against a normal of 5 days and 1.5 inches. The warmest day looks like 23 October (74.1°), the coolest 17 October (37.8°).
63.9°/51°
Average high / low
+3.4°
Above normal
2 / 5
Wet days / normal
0.8 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
15 October – 24 October
64.9°
58.9°
+3.3°
25 October – 3 November
62.2°
55.1°
+3.9°
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, 1660° / 47°0.03
60 °
Prospect Heights, Friday, 16 October
Light rain. High 60°, low 47°.
Pressure30.06 inHg
Wind13.7 mph NW
Humidity75%
Visibility6.2 mi
Dew point44°
Sat, 1756° / 38°0
56 °
Prospect Heights, Saturday, 17 October
Clear. High 56°, low 38°.
Pressure30.53 inHg
Wind5.6 mph SW
Humidity48%
Visibility6.2 mi
Dew point32°
Sun, 1860° / 42°0
60 °
Prospect Heights, Sunday, 18 October
Clear. High 60°, low 42°.
Pressure30.45 inHg
Wind12.3 mph SW
Humidity58%
Visibility6.2 mi
Dew point42°
Mon, 1962° / 43°0
62 °
Prospect Heights, Monday, 19 October
Clear. High 62°, low 43°.
Pressure30.39 inHg
Wind5 mph S
Humidity61%
Visibility6.2 mi
Dew point44°
Tue, 2065° / 47°0
65 °
Prospect Heights, Tuesday, 20 October
Clear. High 65°, low 47°.
Pressure30.36 inHg
Wind4.4 mph E
Humidity49%
Visibility—
Dew point43°
Wed, 2168° / 46°0
68 °
Prospect Heights, Wednesday, 21 October
Mostly clear. High 68°, low 46°.
Pressure30.30 inHg
Wind4.3 mph S
Humidity44%
Visibility—
Dew point41°
Thu, 2272° / 56°0
72 °
Prospect Heights, Thursday, 22 October
Overcast. High 72°, low 56°.
Pressure30.24 inHg
Wind5.5 mph S
Humidity29%
Visibility—
Dew point35°
Fri, 2374° / 59°0
74 °
Prospect Heights, Friday, 23 October
Partly cloudy. High 74°, low 59°.
Pressure30.21 inHg
Wind8.4 mph SE
Humidity26%
Visibility—
Dew point34°
Sat, 2470° / 60°0
70 °
Prospect Heights, Saturday, 24 October
Overcast. High 70°, low 60°.
Pressure30.24 inHg
Wind6.8 mph S
Humidity27%
Visibility—
Dew point32°
Sun, 2570° / 58°0
70 °
Prospect Heights, Sunday, 25 October
Overcast. High 70°, low 58°.
Pressure30.27 inHg
Wind6 mph E
Humidity31%
Visibility—
Dew point37°
Mon, 2666° / 58°0
66 °
Prospect Heights, Monday, 26 October
Overcast. High 66°, low 58°.
Pressure30.09 inHg
Wind8.8 mph SE
Humidity44%
Visibility—
Dew point42°
Tue, 2762° / 53°0
62 °
Prospect Heights, Tuesday, 27 October
Overcast. High 62°, low 53°.
Pressure30.00 inHg
Wind10.5 mph W
Humidity56%
Visibility—
Dew point43°
Wed, 2859° / 53°0.46
59 °
Prospect Heights, Wednesday, 28 October
Rain. High 59°, low 53°.
Pressure29.74 inHg
Wind12.4 mph E
Humidity68%
Visibility—
Dew point44°
Thu, 2957° / 52°0.01
57 °
Prospect Heights, Thursday, 29 October
Light rain. High 57°, low 52°.
Pressure29.80 inHg
Wind9 mph W
Humidity85%
Visibility—
Dew point50°
Fri, 3060° / 49°0
60 °
Prospect Heights, Friday, 30 October
Clear. High 60°, low 49°.
Pressure29.97 inHg
Wind12.2 mph W
Humidity37%
Visibility—
Dew point32°
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.