Monthly outlook for Mount Prospect, IL: average high 63.1°, average low 51°. That is 2.3° above the climate normal for October. Precipitation is expected on 6 days (about 2.6 inches), against a normal of 5 days and 1.8 inches. The warmest day looks like 12 October (84.9°), the coolest 24 October (37.9°).
63.1°/51°
Average high / low
+2.3°
Above normal
6 / 5
Wet days / normal
2.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
12 October – 21 October
69.2°
60.1°
+5°
22 October – 31 October
52.9°
56.5°
-2°
1 November – 10 November
at normal
52.1°
—
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).
Tue, 1385° / 65°0
85 °
Mount Prospect, Tuesday, 13 October
Clear. High 85°, low 65°.
Pressure29.80 inHg
Wind10.3 mph W
Humidity67%
Visibility6.2 mi
Dew point66°
Wed, 1468° / 58°0.14
68 °
Mount Prospect, Wednesday, 14 October
Rain. High 68°, low 58°.
Pressure30.09 inHg
Wind9.6 mph NE
Humidity72%
Visibility6.2 mi
Dew point59°
Thu, 1562° / 59°0.25
62 °
Mount Prospect, Thursday, 15 October
Light rain. High 62°, low 59°.
Pressure30.06 inHg
Wind6.8 mph E
Humidity89%
Visibility4.4 mi
Dew point58°
Fri, 1658° / 47°0.07
58 °
Mount Prospect, Friday, 16 October
Light rain. High 58°, low 47°.
Pressure30.33 inHg
Wind21.1 mph NW
Humidity47%
Visibility—
Dew point37°
Sat, 1756° / 40°0
56 °
Mount Prospect, Saturday, 17 October
Clear. High 56°, low 40°.
Pressure30.47 inHg
Wind9.2 mph S
Humidity42%
Visibility—
Dew point31°
Sun, 1860° / 43°0
60 °
Mount Prospect, Sunday, 18 October
Clear. High 60°, low 43°.
Pressure30.36 inHg
Wind14.3 mph SW
Humidity25%
Visibility—
Dew point20°
Mon, 1968° / 50°0
68 °
Mount Prospect, Monday, 19 October
Overcast. High 68°, low 50°.
Pressure30.30 inHg
Wind10.2 mph SW
Humidity36%
Visibility—
Dew point34°
Tue, 2072° / 56°0
72 °
Mount Prospect, Tuesday, 20 October
Overcast. High 72°, low 56°.
Pressure30.18 inHg
Wind9.3 mph S
Humidity48%
Visibility—
Dew point48°
Wed, 2178° / 63°0.25
78 °
Mount Prospect, Wednesday, 21 October
Rain. High 78°, low 63°.
Pressure30.00 inHg
Wind14 mph S
Humidity51%
Visibility—
Dew point55°
Thu, 2266° / 52°1.14
66 °
Mount Prospect, Thursday, 22 October
Rain. High 66°, low 52°.
Pressure29.71 inHg
Wind14.9 mph S
Humidity59%
Visibility—
Dew point45°
Fri, 2350° / 43°0
50 °
Mount Prospect, Friday, 23 October
Overcast. High 50°, low 43°.
Pressure29.97 inHg
Wind12.7 mph NW
Humidity48%
Visibility—
Dew point28°
Sat, 2451° / 38°0
51 °
Mount Prospect, Saturday, 24 October
Mostly clear. High 51°, low 38°.
Pressure30.15 inHg
Wind9.6 mph NW
Humidity40%
Visibility—
Dew point25°
Sun, 2548° / 46°0.72
48 °
Mount Prospect, Sunday, 25 October
Rain. High 48°, low 46°.
Pressure29.85 inHg
Wind6.1 mph SE
Humidity89%
Visibility—
Dew point44°
Mon, 2654° / 47°0.02
54 °
Mount Prospect, Monday, 26 October
Light rain. High 54°, low 47°.
Pressure30.00 inHg
Wind8 mph NE
Humidity56%
Visibility—
Dew point38°
Tue, 2748° / 46°0
48 °
Mount Prospect, Tuesday, 27 October
Overcast. High 48°, low 46°.
Pressure29.97 inHg
Wind9.1 mph NW
Humidity55%
Visibility—
Dew point33°
From day 17 onward the outlook is built from 60-year climate statistics
Wed, 2855° / 44°0.05
55 °
Mount Prospect, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high55°
Average low44°
Average precipitation0.05 in
Chance of precipitation20%
Record high72° (1999)
Record low29° (1976)
Thu, 2955° / 43°0.06
55 °
Mount Prospect, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high55°
Average low43°
Average precipitation0.06 in
Chance of precipitation22%
Record high79° (2024)
Record low30° (1988)
Fri, 3057° / 44°0.11
57 °
Mount Prospect, Friday, 30 October
Climate normal for this date — 60-year average.
Average high57°
Average low44°
Average precipitation0.11 in
Chance of precipitation30%
Record high77° (2024)
Record low29° (2020)
Sat, 3156° / 44°0.14
56 °
Mount Prospect, 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 °
Mount Prospect, 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 °
Mount Prospect, 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 °
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)
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.