As of 01:37 CDT

Weather in Grayslake, IL

44°Current weather

Grayslake, Sunday, 18 October, 01:37

Clear. Feels like 38°. High 61°, low 43°.

Pressure30.39 inHg
Wind9.2 mph SW
Humidity77%
Visibility6.2 mi
Dew point37°

Monthly outlook for Grayslake, IL: average high 62.6°, average low 47.5°. That is 3.9° 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 (68.2°), the coolest 26 October (35.5°).

62.6°/47.5°
Average high / low
+3.9°
Above normal
1 / 5
Wet days / normal
0.1 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
18 October – 27 October62.3°56.7°+3.1°
28 October – 6 November63.1°52.7°+5.8°
7 November – 16 Novemberat normal47.2°—

October records over 66 years

86.9°3 October 2025All-time high
26.1°30 October 1988All-time low

Climate normals and records are computed from the nearest reference point — Round Lake Beach (4 mi).

Mon, 1963° / 44°0Clear
63 °Clear

Grayslake, Monday, 19 October

Clear. High 63°, low 44°.

Pressure30.39 inHg
Wind3.8 mph SW
Humidity59%
Visibility6.2 mi
Dew point45°
Tue, 2063° / 45°0Partly cloudy
63 °Partly cloudy

Grayslake, Tuesday, 20 October

Partly cloudy. High 63°, low 45°.

Pressure30.42 inHg
Wind4.3 mph SE
Humidity67%
Visibility6.2 mi
Dew point51°
Wed, 2165° / 47°0Clear
65 °Clear

Grayslake, Wednesday, 21 October

Clear. High 65°, low 47°.

Pressure30.27 inHg
Wind4 mph SW
Humidity59%
Visibility6.2 mi
Dew point47°
Thu, 2265° / 50°0Clear
65 °Clear

Grayslake, Thursday, 22 October

Clear. High 65°, low 50°.

Pressure30.27 inHg
Wind6.9 mph E
Humidity60%
Visibility—
Dew point49°
Fri, 2366° / 54°0Light rain
66 °Light rain

Grayslake, Friday, 23 October

Light rain. High 66°, low 54°.

Pressure30.36 inHg
Wind9.6 mph SE
Humidity57%
Visibility—
Dew point47°
Sat, 2468° / 56°0Overcast
68 °Overcast

Grayslake, Saturday, 24 October

Overcast. High 68°, low 56°.

Pressure30.21 inHg
Wind14.4 mph S
Humidity41%
Visibility—
Dew point41°
Sun, 2561° / 42°0Overcast
61 °Overcast

Grayslake, Sunday, 25 October

Overcast. High 61°, low 42°.

Pressure30.39 inHg
Wind12.8 mph SW
Humidity57%
Visibility—
Dew point34°
Mon, 2655° / 35°0Clear
55 °Clear

Grayslake, Monday, 26 October

Clear. High 55°, low 35°.

Pressure30.39 inHg
Wind8.3 mph W
Humidity35%
Visibility—
Dew point24°
Tue, 2756° / 37°0Overcast
56 °Overcast

Grayslake, Tuesday, 27 October

Overcast. High 56°, low 37°.

Pressure30.30 inHg
Wind8.5 mph SW
Humidity34%
Visibility—
Dew point25°
Wed, 2859° / 49°0Overcast
59 °Overcast

Grayslake, Wednesday, 28 October

Overcast. High 59°, low 49°.

Pressure30.06 inHg
Wind16 mph S
Humidity63%
Visibility—
Dew point46°
Thu, 2964° / 60°0.02Light rain
64 °Light rain

Grayslake, Thursday, 29 October

Light rain. High 64°, low 60°.

Pressure29.77 inHg
Wind21.6 mph SW
Humidity62%
Visibility—
Dew point49°
Fri, 3064° / 51°0Clear
64 °Clear

Grayslake, Friday, 30 October

Clear. High 64°, low 51°.

Pressure29.91 inHg
Wind11.9 mph W
Humidity23%
Visibility—
Dew point24°
Sat, 3163° / 50°0.04Light rain
63 °Light rain

Grayslake, Saturday, 31 October

Light rain. High 63°, low 50°.

Pressure30.06 inHg
Wind16.3 mph SE
Humidity39%
Visibility—
Dew point36°
Sun, 0163° / 50°0Light rain
63 °Light rain

Grayslake, Sunday, 1 November

Light rain. High 63°, low 50°.

Pressure29.77 inHg
Wind20.4 mph W
Humidity44%
Visibility—
Dew point40°
Mon, 0265° / 47°0Clear
65 °Clear

Grayslake, Monday, 2 November

Clear. High 65°, low 47°.

Pressure30.09 inHg
Wind12.5 mph S
Humidity34%
Visibility—
Dew point33°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0351° / 40°0.06Climate normal
51 °Climate normal

Grayslake, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high51°
Average low40°
Average precipitation0.06 in
Chance of precipitation30%
Record high70° (1987)
Record low17° (1991)
Wed, 0451° / 41°0.1Climate normal
51 °Climate normal

Grayslake, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high51°
Average low41°
Average precipitation0.1 in
Chance of precipitation32%
Record high69° (2022)
Record low15° (1991)
Thu, 0551° / 40°0.12Climate normal
51 °Climate normal

Grayslake, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high51°
Average low40°
Average precipitation0.12 in
Chance of precipitation28%
Record high71° (1978)
Record low20° (1991)
Fri, 0651° / 38°0.09Climate normal
51 °Climate normal

Grayslake, Friday, 6 November

Climate normal for this date — 60-year average.

Average high51°
Average low38°
Average precipitation0.09 in
Chance of precipitation30%
Record high70° (2020)
Record low22° (1991)
Sat, 0750° / 38°0.05Climate normal
50 °Climate normal

Grayslake, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high50°
Average low38°
Average precipitation0.05 in
Chance of precipitation18%
Record high68° (2020)
Record low14° (1991)
Sun, 0850° / 38°0.04Climate normal
50 °Climate normal

Grayslake, Sunday, 8 November

Climate normal for this date — 60-year average.

Average high50°
Average low38°
Average precipitation0.04 in
Chance of precipitation18%
Record high73° (2020)
Record low15° (1991)
Mon, 0950° / 38°0.11Climate normal
50 °Climate normal

Grayslake, Monday, 9 November

Climate normal for this date — 60-year average.

Average high50°
Average low38°
Average precipitation0.11 in
Chance of precipitation33%
Record high73° (2020)
Record low20° (1991)
Tue, 1049° / 37°0.11Climate normal
49 °Climate normal

Grayslake, Tuesday, 10 November

Climate normal for this date — 60-year average.

Average high49°
Average low37°
Average precipitation0.11 in
Chance of precipitation38%
Record high72° (2022)
Record low16° (2017)
Wed, 1146° / 35°0.08Climate normal
46 °Climate normal

Grayslake, Wednesday, 11 November

Climate normal for this date — 60-year average.

Average high46°
Average low35°
Average precipitation0.08 in
Chance of precipitation35%
Record high67° (1964)
Record low15° (2019)
Thu, 1245° / 34°0.06Climate normal
45 °Climate normal

Grayslake, Thursday, 12 November

Climate normal for this date — 60-year average.

Average high45°
Average low34°
Average precipitation0.06 in
Chance of precipitation22%
Record high64° (1964)
Record low3° (2019)
Fri, 1345° / 33°0.05Climate normal
45 °Climate normal

Grayslake, Friday, 13 November

Climate normal for this date — 60-year average.

Average high45°
Average low33°
Average precipitation0.05 in
Chance of precipitation25%
Record high67° (1999)
Record low2° (2019)
Sat, 1446° / 34°0.07Climate normal
46 °Climate normal

Grayslake, Saturday, 14 November

Climate normal for this date — 60-year average.

Average high46°
Average low34°
Average precipitation0.07 in
Chance of precipitation28%
Record high66° (1971)
Record low15° (1986)
Sun, 1546° / 35°0.08Climate normal
46 °Climate normal

Grayslake, Sunday, 15 November

Climate normal for this date — 60-year average.

Average high46°
Average low35°
Average precipitation0.08 in
Chance of precipitation28%
Record high68° (2025)
Record low17° (2019)
Mon, 1646° / 34°0.05Climate normal
46 °Climate normal

Grayslake, Monday, 16 November

Climate normal for this date — 60-year average.

Average high46°
Average low34°
Average precipitation0.05 in
Chance of precipitation17%
Record high62° (1988)
Record low21° (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 Grayslake, 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 Grayslake, 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.