Monthly outlook for Matteson, IL: average high 78.4°, average low 64.1°. That is 0.9° below the climate normal for August. Precipitation is expected on 6 days (about 2.5 inches), against a normal of 6 days and 1.9 inches. The warmest day looks like 11 August (85.6°), the coolest 23 August (53°).
78.4°/64.1°
Average high / low
−0.9°
Below normal
6 / 6
Wet days / normal
2.5 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
78.5°
80.1°
-0.9°
18 August – 27 August
78.2°
80°
-1°
28 August – 6 September
at normal
78.6°
—
August records over 66 years
97°24 August 2023All-time high
46.8°29 August 1965All-time low
Climate normals and records are computed from the nearest reference point — Orland Hills (7 mi).
Sun, 0983° / 65°1.6
83 °
Matteson, Sunday, 9 August
Heavy rain. High 83°, low 65°.
Pressure29.94 inHg
Wind11.1 mph SW
Humidity77%
Visibility6.2 mi
Dew point74°
Mon, 1083° / 72°0.07
83 °
Matteson, Monday, 10 August
Rain. High 83°, low 72°.
Pressure29.91 inHg
Wind6.5 mph SE
Humidity75%
Visibility6.2 mi
Dew point72°
Tue, 1186° / 72°0.2
86 °
Matteson, Tuesday, 11 August
Rain. High 86°, low 72°.
Pressure29.77 inHg
Wind16.8 mph SW
Humidity79%
Visibility6.2 mi
Dew point74°
Wed, 1279° / 69°0
79 °
Matteson, Wednesday, 12 August
Light rain. High 79°, low 69°.
Pressure29.85 inHg
Wind4.9 mph NE
Humidity74%
Visibility6.2 mi
Dew point67°
Thu, 1372° / 62°0.02
72 °
Matteson, Thursday, 13 August
Light rain. High 72°, low 62°.
Pressure29.94 inHg
Wind12.1 mph NE
Humidity68%
Visibility—
Dew point60°
Fri, 1474° / 60°0
74 °
Matteson, Friday, 14 August
Clear. High 74°, low 60°.
Pressure30.18 inHg
Wind9.6 mph NE
Humidity49%
Visibility—
Dew point52°
Sat, 1574° / 56°0
74 °
Matteson, Saturday, 15 August
Overcast. High 74°, low 56°.
Pressure30.33 inHg
Wind6.5 mph SE
Humidity55%
Visibility—
Dew point53°
Sun, 1677° / 57°0
77 °
Matteson, Sunday, 16 August
Mostly clear. High 77°, low 57°.
Pressure30.21 inHg
Wind9.8 mph S
Humidity61%
Visibility—
Dew point58°
Mon, 1775° / 68°0.09
75 °
Matteson, Monday, 17 August
Light rain. High 75°, low 68°.
Pressure30.00 inHg
Wind6.8 mph S
Humidity93%
Visibility—
Dew point67°
Tue, 1883° / 67°0
83 °
Matteson, Tuesday, 18 August
Partly cloudy. High 83°, low 67°.
Pressure30.00 inHg
Wind8.3 mph NE
Humidity57%
Visibility—
Dew point64°
Wed, 1982° / 64°0.38
82 °
Matteson, Wednesday, 19 August
Rain. High 82°, low 64°.
Pressure29.91 inHg
Wind8.4 mph S
Humidity67%
Visibility—
Dew point68°
Thu, 2080° / 66°0.08
80 °
Matteson, Thursday, 20 August
Light rain. High 80°, low 66°.
Pressure29.88 inHg
Wind9.1 mph NE
Humidity63%
Visibility—
Dew point65°
Fri, 2180° / 65°0
80 °
Matteson, Friday, 21 August
Partly cloudy. High 80°, low 65°.
Pressure29.97 inHg
Wind9.2 mph NE
Humidity55%
Visibility—
Dew point60°
Sat, 2278° / 61°0.02
78 °
Matteson, Saturday, 22 August
Light rain. High 78°, low 61°.
Pressure29.91 inHg
Wind15.5 mph NE
Humidity66%
Visibility—
Dew point64°
Sun, 2366° / 53°0
66 °
Matteson, Sunday, 23 August
Mostly clear. High 66°, low 53°.
Pressure30.24 inHg
Wind11.9 mph NE
Humidity46%
Visibility—
Dew point43°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2480° / 65°0.13
80 °
Matteson, Monday, 24 August
Climate normal for this date — 60-year average.
Average high80°
Average low65°
Average precipitation0.13 in
Chance of precipitation27%
Record high97° (2023)
Record low55° (1965)
Tue, 2580° / 65°0.09
80 °
Matteson, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high80°
Average low65°
Average precipitation0.09 in
Chance of precipitation28%
Record high91° (2003)
Record low51° (2017)
Wed, 2681° / 66°0.15
81 °
Matteson, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high81°
Average low66°
Average precipitation0.15 in
Chance of precipitation40%
Record high93° (2024)
Record low53° (1964)
Thu, 2781° / 66°0.12
81 °
Matteson, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high81°
Average low66°
Average precipitation0.12 in
Chance of precipitation33%
Record high95° (2024)
Record low54° (2025)
Fri, 2880° / 65°0.15
80 °
Matteson, Friday, 28 August
Climate normal for this date — 60-year average.
Average high80°
Average low65°
Average precipitation0.15 in
Chance of precipitation35%
Record high92° (1984)
Record low50° (1986)
Sat, 2980° / 65°0.13
80 °
Matteson, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high80°
Average low65°
Average precipitation0.13 in
Chance of precipitation37%
Record high93° (1984)
Record low47° (1965)
Sun, 3079° / 64°0.09
79 °
Matteson, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high79°
Average low64°
Average precipitation0.09 in
Chance of precipitation32%
Record high92° (2013)
Record low51° (1986)
Mon, 3179° / 64°0.06
79 °
Matteson, Monday, 31 August
Climate normal for this date — 60-year average.
Average high79°
Average low64°
Average precipitation0.06 in
Chance of precipitation23%
Record high89° (2012)
Record low53° (2023)
Tue, 0179° / 63°0.13
79 °
Matteson, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.13 in
Chance of precipitation30%
Record high95° (2011)
Record low51° (2009)
Wed, 0279° / 64°0.07
79 °
Matteson, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high79°
Average low64°
Average precipitation0.07 in
Chance of precipitation27%
Record high92° (2008)
Record low49° (2017)
Thu, 0379° / 64°0.07
79 °
Matteson, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high79°
Average low64°
Average precipitation0.07 in
Chance of precipitation28%
Record high92° (2023)
Record low51° (1974)
Fri, 0477° / 63°0.09
77 °
Matteson, Friday, 4 September
Climate normal for this date — 60-year average.
Average high77°
Average low63°
Average precipitation0.09 in
Chance of precipitation32%
Record high90° (2023)
Record low50° (2025)
Sat, 0578° / 62°0.07
78 °
Matteson, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.07 in
Chance of precipitation23%
Record high89° (2023)
Record low51° (1974)
Sun, 0677° / 62°0.11
77 °
Matteson, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high77°
Average low62°
Average precipitation0.11 in
Chance of precipitation42%
Record high91° (1990)
Record low49° (1962)
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 Matteson, 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 Matteson, 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.