As of 17:32 CDT

Weather in Grayslake, IL

55°Current weather

Grayslake, Saturday, 17 October, 17:32

Clear. Feels like 52°. High 56°, low 35°.

Pressure30.42 inHg
Wind15 mph SW
Humidity53%
Visibility6.2 mi
Dew point38°

Monthly outlook for Grayslake, IL: average high 63.1°, average low 48.2°. That is 3.9° above the climate normal for October. Precipitation is expected on 4 days (about 2.5 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 25 October (71.3°), the coolest 17 October (34.9°).

63.1°/48.2°
Average high / low
+3.9°
Above normal
4 / 5
Wet days / normal
2.5 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
17 October – 26 October64.5°57.1°+4.1°
27 October – 5 November60.6°53.1°+4.2°
6 November – 15 Novemberat normal47.7°—

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).

Sun, 1862° / 43°0Clear
62 °Clear

Grayslake, Sunday, 18 October

Clear. High 62°, low 43°.

Pressure30.39 inHg
Wind13.6 mph SW
Humidity56%
Visibility6.2 mi
Dew point40°
Mon, 1963° / 44°0Partly cloudy
63 °Partly cloudy

Grayslake, Monday, 19 October

Partly cloudy. High 63°, low 44°.

Pressure30.39 inHg
Wind3.7 mph SW
Humidity60%
Visibility6.2 mi
Dew point45°
Tue, 2064° / 46°0Partly cloudy
64 °Partly cloudy

Grayslake, Tuesday, 20 October

Partly cloudy. High 64°, low 46°.

Pressure30.39 inHg
Wind4.1 mph SE
Humidity66%
Visibility6.2 mi
Dew point51°
Wed, 2165° / 47°0Clear
65 °Clear

Grayslake, Wednesday, 21 October

Clear. High 65°, low 47°.

Pressure30.27 inHg
Wind3.8 mph SW
Humidity59%
Visibility6.2 mi
Dew point47°
Thu, 2264° / 49°0Mostly clear
64 °Mostly clear

Grayslake, Thursday, 22 October

Mostly clear. High 64°, low 49°.

Pressure30.30 inHg
Wind7.4 mph E
Humidity60%
Visibility—
Dew point48°
Fri, 2370° / 51°0Overcast
70 °Overcast

Grayslake, Friday, 23 October

Overcast. High 70°, low 51°.

Pressure30.24 inHg
Wind6.9 mph S
Humidity45%
Visibility—
Dew point46°
Sat, 2467° / 56°0Overcast
67 °Overcast

Grayslake, Saturday, 24 October

Overcast. High 67°, low 56°.

Pressure30.21 inHg
Wind12.5 mph SW
Humidity42%
Visibility—
Dew point40°
Sun, 2571° / 59°0Overcast
71 °Overcast

Grayslake, Sunday, 25 October

Overcast. High 71°, low 59°.

Pressure30.12 inHg
Wind15.8 mph SW
Humidity42%
Visibility—
Dew point45°
Mon, 2664° / 51°0.43Rain
64 °Rain

Grayslake, Monday, 26 October

Rain. High 64°, low 51°.

Pressure30.15 inHg
Wind8.9 mph W
Humidity91%
Visibility—
Dew point52°
Tue, 2752° / 43°0Partly cloudy
52 °Partly cloudy

Grayslake, Tuesday, 27 October

Partly cloudy. High 52°, low 43°.

Pressure30.39 inHg
Wind11.9 mph NE
Humidity50%
Visibility—
Dew point33°
Wed, 2855° / 42°0Overcast
55 °Overcast

Grayslake, Wednesday, 28 October

Overcast. High 55°, low 42°.

Pressure30.33 inHg
Wind10 mph SE
Humidity37%
Visibility—
Dew point28°
Thu, 2957° / 45°0.51Rain
57 °Rain

Grayslake, Thursday, 29 October

Rain. High 57°, low 45°.

Pressure29.91 inHg
Wind13.6 mph S
Humidity93%
Visibility—
Dew point47°
Fri, 3065° / 57°0.17Light rain
65 °Light rain

Grayslake, Friday, 30 October

Light rain. High 65°, low 57°.

Pressure29.83 inHg
Wind14.8 mph S
Humidity70%
Visibility—
Dew point54°
Sat, 3167° / 52°1.38Heavy rain
67 °Heavy rain

Grayslake, Saturday, 31 October

Heavy rain. High 67°, low 52°.

Pressure29.74 inHg
Wind19.5 mph S
Humidity75%
Visibility—
Dew point58°
Sun, 0167° / 49°0Partly cloudy
67 °Partly cloudy

Grayslake, Sunday, 1 November

Partly cloudy. High 67°, low 49°.

Pressure30.12 inHg
Wind8.9 mph S
Humidity46%
Visibility—
Dew point42°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 0252° / 41°0.14Climate normal
52 °Climate normal

Grayslake, Monday, 2 November

Climate normal for this date — 60-year average.

Average high52°
Average low41°
Average precipitation0.14 in
Chance of precipitation37%
Record high72° (1961)
Record low23° (1991)
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)

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.