Monthly outlook for Mount Prospect, IL: average high 62.9°, average low 50°. That is 3.4° above the climate normal for October. Precipitation is expected on 3 days (about 1.1 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 24 October (71.5°), the coolest 18 October (40.7°).
62.9°/50°
Average high / low
+3.4°
Above normal
3 / 5
Wet days / normal
1.1 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
18 October – 27 October
63.8°
57.8°
+3.3°
28 October – 6 November
61.5°
54°
+4.2°
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 (6 mi).
Mon, 1966° / 44°0
66 °
Mount Prospect, Monday, 19 October
Clear. High 66°, low 44°.
Pressure30.39 inHg
Wind3 mph SW
Humidity62%
Visibility6.2 mi
Dew point46°
Tue, 2063° / 45°0
63 °
Mount Prospect, Tuesday, 20 October
Clear. High 63°, low 45°.
Pressure30.39 inHg
Wind3.7 mph SE
Humidity68%
Visibility6.2 mi
Dew point51°
Wed, 2166° / 45°0
66 °
Mount Prospect, Wednesday, 21 October
Clear. High 66°, low 45°.
Pressure30.30 inHg
Wind2.8 mph SW
Humidity59%
Visibility6.2 mi
Dew point49°
Thu, 2264° / 49°0.01
64 °
Mount Prospect, Thursday, 22 October
Light rain. High 64°, low 49°.
Pressure30.33 inHg
Wind3.4 mph E
Humidity72%
Visibility6.2 mi
Dew point54°
Fri, 2362° / 51°0
62 °
Mount Prospect, Friday, 23 October
Clear. High 62°, low 51°.
Pressure30.36 inHg
Wind8.1 mph SE
Humidity63%
Visibility—
Dew point47°
Sat, 2471° / 49°0
71 °
Mount Prospect, Saturday, 24 October
Overcast. High 71°, low 49°.
Pressure30.33 inHg
Wind10.3 mph S
Humidity41%
Visibility—
Dew point41°
Sun, 2567° / 59°0
67 °
Mount Prospect, Sunday, 25 October
Overcast. High 67°, low 59°.
Pressure30.36 inHg
Wind9.3 mph SW
Humidity29%
Visibility—
Dew point33°
Mon, 2658° / 54°0.01
58 °
Mount Prospect, Monday, 26 October
Light rain. High 58°, low 54°.
Pressure30.39 inHg
Wind7.3 mph NE
Humidity51%
Visibility—
Dew point40°
Tue, 2758° / 53°0
58 °
Mount Prospect, Tuesday, 27 October
Overcast. High 58°, low 53°.
Pressure30.36 inHg
Wind6.6 mph E
Humidity50%
Visibility—
Dew point38°
Wed, 2860° / 55°0
60 °
Mount Prospect, Wednesday, 28 October
Overcast. High 60°, low 55°.
Pressure30.24 inHg
Wind3.8 mph SE
Humidity61%
Visibility—
Dew point45°
Thu, 2969° / 56°0
69 °
Mount Prospect, Thursday, 29 October
Light rain. High 69°, low 56°.
Pressure30.03 inHg
Wind10.1 mph SW
Humidity47%
Visibility—
Dew point44°
Fri, 3067° / 55°0.19
67 °
Mount Prospect, Friday, 30 October
Rain. High 67°, low 55°.
Pressure29.83 inHg
Wind12.6 mph SW
Humidity58%
Visibility—
Dew point51°
Sat, 3162° / 49°0
62 °
Mount Prospect, Saturday, 31 October
Clear. High 62°, low 49°.
Pressure30.12 inHg
Wind3.3 mph NW
Humidity37%
Visibility—
Dew point33°
Sun, 0156° / 52°0.4
56 °
Mount Prospect, Sunday, 1 November
Rain. High 56°, low 52°.
Pressure29.94 inHg
Wind8.2 mph E
Humidity91%
Visibility—
Dew point50°
Mon, 0255° / 45°0.51
55 °
Mount Prospect, Monday, 2 November
Rain. High 55°, low 45°.
Pressure30.12 inHg
Wind14 mph N
Humidity76%
Visibility—
Dew point40°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0353° / 41°0.06
53 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 Mount Prospect, 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 Mount Prospect, 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.