Monthly outlook for Deer Park, IL: average high 62.4°, average low 47.6°. That is 4.1° above the climate normal for October. Precipitation is expected on 1 day (about 0.1 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 24 October (68°), the coolest 26 October (36.9°).
62.4°/47.6°
Average high / low
+4.1°
Above normal
1 / 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
62.2°
56.2°
+3.4°
28 October – 6 November
62.8°
52.4°
+5.7°
7 November – 16 November
at normal
47.2°
—
October records over 66 years
87.4°3 October 2025All-time high
27.5°31 October 2019All-time low
Climate normals and records are computed from the nearest reference point — Highwood (14 mi).
Mon, 1963° / 43°0
63 °
Deer Park, Monday, 19 October
Clear. High 63°, low 43°.
Pressure30.39 inHg
Wind3.3 mph SW
Humidity59%
Visibility6.2 mi
Dew point45°
Tue, 2064° / 45°0
64 °
Deer Park, Tuesday, 20 October
Clear. High 64°, low 45°.
Pressure30.39 inHg
Wind3.8 mph SE
Humidity66%
Visibility6.2 mi
Dew point50°
Wed, 2165° / 46°0
65 °
Deer Park, Wednesday, 21 October
Clear. High 65°, low 46°.
Pressure30.27 inHg
Wind4 mph SW
Humidity59%
Visibility6.2 mi
Dew point47°
Thu, 2265° / 48°0.01
65 °
Deer Park, Thursday, 22 October
Light rain. High 65°, low 48°.
Pressure30.27 inHg
Wind6.1 mph NE
Humidity60%
Visibility—
Dew point49°
Fri, 2367° / 53°0
67 °
Deer Park, Friday, 23 October
Partly cloudy. High 67°, low 53°.
Pressure30.36 inHg
Wind8.3 mph SE
Humidity56%
Visibility—
Dew point47°
Sat, 2468° / 55°0
68 °
Deer Park, Saturday, 24 October
Overcast. High 68°, low 55°.
Pressure30.21 inHg
Wind13.7 mph S
Humidity41%
Visibility—
Dew point41°
Sun, 2560° / 43°0
60 °
Deer Park, Sunday, 25 October
Overcast. High 60°, low 43°.
Pressure30.39 inHg
Wind12 mph SW
Humidity58%
Visibility—
Dew point34°
Mon, 2654° / 37°0
54 °
Deer Park, Monday, 26 October
Clear. High 54°, low 37°.
Pressure30.39 inHg
Wind7.3 mph W
Humidity37%
Visibility—
Dew point25°
Tue, 2755° / 39°0
55 °
Deer Park, Tuesday, 27 October
Overcast. High 55°, low 39°.
Pressure30.30 inHg
Wind8.3 mph SW
Humidity35%
Visibility—
Dew point26°
Wed, 2858° / 50°0
58 °
Deer Park, Wednesday, 28 October
Overcast. High 58°, low 50°.
Pressure30.09 inHg
Wind15.6 mph S
Humidity67%
Visibility—
Dew point46°
Thu, 2964° / 59°0.01
64 °
Deer Park, Thursday, 29 October
Light rain. High 64°, low 59°.
Pressure29.80 inHg
Wind21.7 mph S
Humidity65%
Visibility—
Dew point49°
Fri, 3064° / 52°0
64 °
Deer Park, Friday, 30 October
Clear. High 64°, low 52°.
Pressure29.91 inHg
Wind10.5 mph W
Humidity24%
Visibility—
Dew point25°
Sat, 3164° / 51°0.07
64 °
Deer Park, Saturday, 31 October
Light rain. High 64°, low 51°.
Pressure30.06 inHg
Wind13.2 mph SE
Humidity36%
Visibility—
Dew point35°
Sun, 0163° / 51°0.01
63 °
Deer Park, Sunday, 1 November
Light rain. High 63°, low 51°.
Pressure29.77 inHg
Wind18.7 mph W
Humidity46%
Visibility—
Dew point41°
Mon, 0264° / 47°0
64 °
Deer Park, Monday, 2 November
Clear. High 64°, low 47°.
Pressure30.09 inHg
Wind11.3 mph S
Humidity35%
Visibility—
Dew point34°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0351° / 42°0.06
51 °
Deer Park, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high51°
Average low42°
Average precipitation0.06 in
Chance of precipitation23%
Record high70° (2022)
Record low20° (1991)
Wed, 0451° / 43°0.09
51 °
Deer Park, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high51°
Average low43°
Average precipitation0.09 in
Chance of precipitation28%
Record high69° (2022)
Record low18° (1991)
Thu, 0551° / 42°0.12
51 °
Deer Park, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high51°
Average low42°
Average precipitation0.12 in
Chance of precipitation28%
Record high68° (2022)
Record low22° (1991)
Fri, 0651° / 40°0.09
51 °
Deer Park, Friday, 6 November
Climate normal for this date — 60-year average.
Average high51°
Average low40°
Average precipitation0.09 in
Chance of precipitation28%
Record high70° (2020)
Record low25° (1991)
Sat, 0750° / 41°0.05
50 °
Deer Park, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high50°
Average low41°
Average precipitation0.05 in
Chance of precipitation18%
Record high68° (2020)
Record low21° (1991)
Sun, 0849° / 41°0.06
49 °
Deer Park, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high49°
Average low41°
Average precipitation0.06 in
Chance of precipitation17%
Record high72° (2020)
Record low18° (2019)
Mon, 0950° / 40°0.12
50 °
Deer Park, Monday, 9 November
Climate normal for this date — 60-year average.
Average high50°
Average low40°
Average precipitation0.12 in
Chance of precipitation38%
Record high72° (2020)
Record low23° (2018)
Tue, 1049° / 40°0.11
49 °
Deer Park, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high49°
Average low40°
Average precipitation0.11 in
Chance of precipitation37%
Record high72° (2022)
Record low18° (2017)
Wed, 1147° / 38°0.08
47 °
Deer Park, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high47°
Average low38°
Average precipitation0.08 in
Chance of precipitation33%
Record high64° (1964)
Record low16° (2019)
Thu, 1245° / 36°0.06
45 °
Deer Park, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high45°
Average low36°
Average precipitation0.06 in
Chance of precipitation20%
Record high63° (1964)
Record low7° (2019)
Fri, 1345° / 36°0.05
45 °
Deer Park, Friday, 13 November
Climate normal for this date — 60-year average.
Average high45°
Average low36°
Average precipitation0.05 in
Chance of precipitation23%
Record high63° (1999)
Record low8° (2019)
Sat, 1446° / 37°0.07
46 °
Deer Park, Saturday, 14 November
Climate normal for this date — 60-year average.
Average high46°
Average low37°
Average precipitation0.07 in
Chance of precipitation30%
Record high64° (2025)
Record low18° (1986)
Sun, 1546° / 37°0.09
46 °
Deer Park, Sunday, 15 November
Climate normal for this date — 60-year average.
Average high46°
Average low37°
Average precipitation0.09 in
Chance of precipitation28%
Record high69° (2025)
Record low20° (2019)
Mon, 1646° / 37°0.05
46 °
Deer Park, Monday, 16 November
Climate normal for this date — 60-year average.
Average high46°
Average low37°
Average precipitation0.05 in
Chance of precipitation18%
Record high62° (2023)
Record low24° (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 Deer Park, 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 Deer Park, 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.