Monthly outlook for Third Lake, IL: average high 65.2°, average low 52°. That is 4.1° above the climate normal for October. Precipitation is expected on 7 days (about 1.4 inches), against a normal of 5 days and 1.8 inches. The warmest day looks like 12 October (85.5°), the coolest 26 October (37.9°).
65.2°/52°
Average high / low
+4.1°
Above normal
7 / 5
Wet days / normal
1.4 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
12 October – 21 October
64.8°
58.9°
+3.3°
22 October – 31 October
65.9°
55.3°
+5.9°
1 November – 10 November
at normal
50.8°
—
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).
Tue, 1379° / 61°0.13
79 °
Third Lake, Tuesday, 13 October
Rain. High 79°, low 61°.
Pressure29.83 inHg
Wind11.7 mph W
Humidity65%
Visibility6.2 mi
Dew point60°
Wed, 1467° / 58°0.13
67 °
Third Lake, Wednesday, 14 October
Rain. High 67°, low 58°.
Pressure30.12 inHg
Wind7 mph NE
Humidity68%
Visibility6.2 mi
Dew point56°
Thu, 1560° / 56°0.44
60 °
Third Lake, Thursday, 15 October
Heavy rain. High 60°, low 56°.
Pressure30.09 inHg
Wind8.4 mph E
Humidity87%
Visibility6.2 mi
Dew point55°
Fri, 1657° / 48°0
57 °
Third Lake, Friday, 16 October
Partly cloudy. High 57°, low 48°.
Pressure30.30 inHg
Wind20.9 mph N
Humidity55%
Visibility6.2 mi
Dew point39°
Sat, 1759° / 42°0
59 °
Third Lake, Saturday, 17 October
Clear. High 59°, low 42°.
Pressure30.45 inHg
Wind11.4 mph SW
Humidity41%
Visibility—
Dew point32°
Sun, 1858° / 43°0
58 °
Third Lake, Sunday, 18 October
Clear. High 58°, low 43°.
Pressure30.24 inHg
Wind17.7 mph SW
Humidity43%
Visibility—
Dew point33°
Mon, 1957° / 48°0.06
57 °
Third Lake, Monday, 19 October
Light rain. High 57°, low 48°.
Pressure30.18 inHg
Wind12.5 mph SW
Humidity56%
Visibility—
Dew point41°
Tue, 2059° / 52°0.09
59 °
Third Lake, Tuesday, 20 October
Light rain. High 59°, low 52°.
Pressure30.24 inHg
Wind5.6 mph S
Humidity82%
Visibility—
Dew point53°
Wed, 2167° / 55°0
67 °
Third Lake, Wednesday, 21 October
Partly cloudy. High 67°, low 55°.
Pressure30.33 inHg
Wind11.1 mph SE
Humidity68%
Visibility—
Dew point54°
Thu, 2273° / 56°0
73 °
Third Lake, Thursday, 22 October
Overcast. High 73°, low 56°.
Pressure30.30 inHg
Wind11.5 mph S
Humidity64%
Visibility—
Dew point54°
Fri, 2371° / 64°0.08
71 °
Third Lake, Friday, 23 October
Light rain. High 71°, low 64°.
Pressure30.21 inHg
Wind13.4 mph SW
Humidity85%
Visibility—
Dew point63°
Sat, 2472° / 63°0.45
72 °
Third Lake, Saturday, 24 October
Rain. High 72°, low 63°.
Pressure29.94 inHg
Wind22.9 mph SW
Humidity59%
Visibility—
Dew point56°
Sun, 2566° / 48°0.03
66 °
Third Lake, Sunday, 25 October
Light rain. High 66°, low 48°.
Pressure29.85 inHg
Wind19.6 mph SW
Humidity66%
Visibility—
Dew point45°
Mon, 2655° / 38°0
55 °
Third Lake, Monday, 26 October
Clear. High 55°, low 38°.
Pressure30.15 inHg
Wind15.5 mph NW
Humidity44%
Visibility—
Dew point30°
Tue, 2759° / 41°0
59 °
Third Lake, Tuesday, 27 October
Overcast. High 59°, low 41°.
Pressure29.77 inHg
Wind20.5 mph NW
Humidity58%
Visibility—
Dew point43°
From day 17 onward the outlook is built from 60-year climate statistics
Wed, 2854° / 43°0.05
54 °
Third Lake, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high54°
Average low43°
Average precipitation0.05 in
Chance of precipitation22%
Record high68° (1999)
Record low30° (1976)
Thu, 2954° / 42°0.06
54 °
Third Lake, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high54°
Average low42°
Average precipitation0.06 in
Chance of precipitation20%
Record high78° (2024)
Record low28° (1988)
Fri, 3056° / 43°0.09
56 °
Third Lake, Friday, 30 October
Climate normal for this date — 60-year average.
Average high56°
Average low43°
Average precipitation0.09 in
Chance of precipitation30%
Record high76° (2024)
Record low26° (1988)
Sat, 3154° / 43°0.12
54 °
Third Lake, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high54°
Average low43°
Average precipitation0.12 in
Chance of precipitation42%
Record high71° (1974)
Record low28° (2019)
Sun, 0153° / 42°0.16
53 °
Third Lake, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high53°
Average low42°
Average precipitation0.16 in
Chance of precipitation45%
Record high71° (2016)
Record low20° (2019)
Mon, 0252° / 41°0.14
52 °
Third Lake, 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°0.06
51 °
Third Lake, 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°0.1
51 °
Third Lake, 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°0.12
51 °
Third Lake, 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°0.09
51 °
Third Lake, 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°0.05
50 °
Third Lake, 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°0.04
50 °
Third Lake, 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°0.11
50 °
Third Lake, 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°0.11
49 °
Third Lake, 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)
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 Third Lake, 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 Third Lake, 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.