Monthly outlook for Highwood, IL: average high 77.6°, average low 65.3°. That is 0.2° below the climate normal for August. Precipitation is expected on 3 days (about 3.0 inches), against a normal of 6 days and 1.8 inches. The warmest day looks like 10 August (85.3°), the coolest 20 August (57.3°).
77.6°/65.3°
Average high / low
−0.2°
Below normal
3 / 6
Wet days / normal
3.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
79.1°
78.1°
+0.5°
18 August – 27 August
75°
77.8°
-1.5°
28 August – 6 September
at normal
76.4°
—
August records over 66 years
98.6°24 August 2023All-time high
52.5°22 August 2024All-time low
Sun, 0985° / 64°1.39
85 °
Highwood, Sunday, 9 August
Heavy rain. High 85°, low 64°.
Pressure29.94 inHg
Wind9.5 mph SW
Humidity62%
Visibility6.2 mi
Dew point68°
Mon, 1085° / 71°0.95
85 °
Highwood, Monday, 10 August
Heavy rain. High 85°, low 71°.
Pressure29.91 inHg
Wind3.3 mph SE
Humidity67%
Visibility6.2 mi
Dew point67°
Tue, 1182° / 70°0.55
82 °
Highwood, Tuesday, 11 August
Heavy rain. High 82°, low 70°.
Pressure29.80 inHg
Wind5 mph E
Humidity92%
Visibility6.2 mi
Dew point69°
Wed, 1281° / 69°0
81 °
Highwood, Wednesday, 12 August
Overcast. High 81°, low 69°.
Pressure29.85 inHg
Wind2.3 mph NW
Humidity64%
Visibility6.2 mi
Dew point65°
Thu, 1371° / 66°0
71 °
Highwood, Thursday, 13 August
Overcast. High 71°, low 66°.
Pressure30.03 inHg
Wind10.9 mph NE
Humidity56%
Visibility—
Dew point53°
Fri, 1475° / 62°0
75 °
Highwood, Friday, 14 August
Clear. High 75°, low 62°.
Pressure30.12 inHg
Wind7.8 mph NE
Humidity49%
Visibility—
Dew point53°
Sat, 1575° / 66°0
75 °
Highwood, Saturday, 15 August
Overcast. High 75°, low 66°.
Pressure30.27 inHg
Wind8.3 mph E
Humidity45%
Visibility—
Dew point51°
Sun, 1674° / 65°0
74 °
Highwood, Sunday, 16 August
Overcast. High 74°, low 65°.
Pressure30.15 inHg
Wind6.1 mph E
Humidity57%
Visibility—
Dew point56°
Mon, 1780° / 66°0.01
80 °
Highwood, Monday, 17 August
Light rain. High 80°, low 66°.
Pressure30.03 inHg
Wind5.1 mph W
Humidity56%
Visibility—
Dew point61°
Tue, 1885° / 69°0
85 °
Highwood, Tuesday, 18 August
Overcast. High 85°, low 69°.
Pressure29.94 inHg
Wind10.9 mph SW
Humidity50%
Visibility—
Dew point61°
Wed, 1975° / 64°0
75 °
Highwood, Wednesday, 19 August
Light rain. High 75°, low 64°.
Pressure29.91 inHg
Wind16.8 mph NW
Humidity60%
Visibility—
Dew point57°
Thu, 2068° / 57°0
68 °
Highwood, Thursday, 20 August
Overcast. High 68°, low 57°.
Pressure30.06 inHg
Wind11.2 mph NW
Humidity53%
Visibility—
Dew point49°
Fri, 2172° / 58°0
72 °
Highwood, Friday, 21 August
Clear. High 72°, low 58°.
Pressure30.09 inHg
Wind9.1 mph NE
Humidity48%
Visibility—
Dew point49°
Sat, 2269° / 63°0.03
69 °
Highwood, Saturday, 22 August
Light rain. High 69°, low 63°.
Pressure29.91 inHg
Wind10.7 mph S
Humidity79%
Visibility—
Dew point58°
Sun, 2382° / 66°0
82 °
Highwood, Sunday, 23 August
Mostly clear. High 82°, low 66°.
Pressure29.88 inHg
Wind14 mph W
Humidity39%
Visibility—
Dew point53°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2478° / 68°0.11
78 °
Highwood, Monday, 24 August
Climate normal for this date — 60-year average.
Average high78°
Average low68°
Average precipitation0.11 in
Chance of precipitation25%
Record high99° (2023)
Record low58° (2025)
Tue, 2578° / 68°0.07
78 °
Highwood, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high78°
Average low68°
Average precipitation0.07 in
Chance of precipitation25%
Record high91° (2024)
Record low54° (2017)
Wed, 2679° / 68°0.14
79 °
Highwood, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high79°
Average low68°
Average precipitation0.14 in
Chance of precipitation35%
Record high94° (2024)
Record low54° (2025)
Thu, 2778° / 69°0.1
78 °
Highwood, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high78°
Average low69°
Average precipitation0.1 in
Chance of precipitation32%
Record high96° (2024)
Record low55° (2025)
Fri, 2878° / 68°0.12
78 °
Highwood, Friday, 28 August
Climate normal for this date — 60-year average.
Average high78°
Average low68°
Average precipitation0.12 in
Chance of precipitation35%
Record high92° (2021)
Record low54° (1986)
Sat, 2978° / 68°0.13
78 °
Highwood, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high78°
Average low68°
Average precipitation0.13 in
Chance of precipitation28%
Record high89° (1984)
Record low54° (1965)
Sun, 3077° / 67°0.09
77 °
Highwood, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high77°
Average low67°
Average precipitation0.09 in
Chance of precipitation27%
Record high91° (2013)
Record low57° (2023)
Mon, 3176° / 67°0.06
76 °
Highwood, Monday, 31 August
Climate normal for this date — 60-year average.
Average high76°
Average low67°
Average precipitation0.06 in
Chance of precipitation20%
Record high89° (2012)
Record low56° (2025)
Tue, 0176° / 67°0.1
76 °
Highwood, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high76°
Average low67°
Average precipitation0.1 in
Chance of precipitation28%
Record high89° (1960)
Record low57° (2017)
Wed, 0277° / 67°0.04
77 °
Highwood, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high77°
Average low67°
Average precipitation0.04 in
Chance of precipitation25%
Record high87° (2023)
Record low50° (2017)
Thu, 0376° / 66°0.09
76 °
Highwood, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high76°
Average low66°
Average precipitation0.09 in
Chance of precipitation27%
Record high92° (2023)
Record low54° (1974)
Fri, 0475° / 66°0.08
75 °
Highwood, Friday, 4 September
Climate normal for this date — 60-year average.
Average high75°
Average low66°
Average precipitation0.08 in
Chance of precipitation30%
Record high91° (2023)
Record low49° (2025)
Sat, 0575° / 65°0.08
75 °
Highwood, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high75°
Average low65°
Average precipitation0.08 in
Chance of precipitation25%
Record high89° (2023)
Record low55° (2017)
Sun, 0675° / 65°0.09
75 °
Highwood, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high75°
Average low65°
Average precipitation0.09 in
Chance of precipitation33%
Record high90° (1990)
Record low49° (2025)
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 Highwood, 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 Highwood, 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.