Monthly outlook for Boulder Hill, IL: average high 78.4°, average low 62.4°. That is 1° below the climate normal for August. Precipitation is expected on 4 days (about 2.2 inches), against a normal of 5 days and 1.8 inches. The warmest day looks like 9 August (89.2°), the coolest 23 August (52.3°).
78.4°/62.4°
Average high / low
−1°
Below normal
4 / 5
Wet days / normal
2.2 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
79.5°
80.3°
-0.4°
18 August – 27 August
76.5°
80.2°
-2.1°
28 August – 6 September
at normal
78.7°
—
August records over 66 years
98.4°24 August 2023All-time high
44.4°29 August 1965All-time low
Climate normals and records are computed from the nearest reference point — Aurora (4 mi).
Sun, 0989° / 63°1.49
89 °
Boulder Hill, Sunday, 9 August
Heavy rain. High 89°, low 63°.
Pressure29.94 inHg
Wind9.4 mph E
Humidity97%
Visibility5.5 mi
Dew point72°
Mon, 1088° / 71°0.03
88 °
Boulder Hill, Monday, 10 August
Light rain. High 88°, low 71°.
Pressure29.91 inHg
Wind10.5 mph SE
Humidity76%
Visibility6.2 mi
Dew point74°
Tue, 1187° / 71°0.13
87 °
Boulder Hill, Tuesday, 11 August
Light rain. High 87°, low 71°.
Pressure29.77 inHg
Wind10.5 mph SW
Humidity89%
Visibility6.2 mi
Dew point73°
Wed, 1280° / 66°0.02
80 °
Boulder Hill, Wednesday, 12 August
Light rain. High 80°, low 66°.
Pressure29.91 inHg
Wind9.6 mph W
Humidity91%
Visibility6.2 mi
Dew point70°
Thu, 1371° / 59°0.04
71 °
Boulder Hill, Thursday, 13 August
Light rain. High 71°, low 59°.
Pressure29.94 inHg
Wind12.7 mph E
Humidity74%
Visibility—
Dew point61°
Fri, 1473° / 56°0
73 °
Boulder Hill, Friday, 14 August
Clear. High 73°, low 56°.
Pressure30.18 inHg
Wind9.8 mph NW
Humidity61%
Visibility—
Dew point56°
Sat, 1573° / 54°0
73 °
Boulder Hill, Saturday, 15 August
Overcast. High 73°, low 54°.
Pressure30.33 inHg
Wind5.7 mph S
Humidity64%
Visibility—
Dew point57°
Sun, 1675° / 57°0
75 °
Boulder Hill, Sunday, 16 August
Partly cloudy. High 75°, low 57°.
Pressure30.18 inHg
Wind10.7 mph S
Humidity69%
Visibility—
Dew point61°
Mon, 1776° / 65°0.01
76 °
Boulder Hill, Monday, 17 August
Light rain. High 76°, low 65°.
Pressure30.00 inHg
Wind6.4 mph S
Humidity87%
Visibility—
Dew point68°
Tue, 1884° / 66°0
84 °
Boulder Hill, Tuesday, 18 August
Overcast. High 84°, low 66°.
Pressure30.00 inHg
Wind7.8 mph NE
Humidity65%
Visibility—
Dew point67°
Wed, 1981° / 63°0.39
81 °
Boulder Hill, Wednesday, 19 August
Rain. High 81°, low 63°.
Pressure29.91 inHg
Wind10.4 mph SW
Humidity76%
Visibility—
Dew point70°
Thu, 2076° / 65°0.02
76 °
Boulder Hill, Thursday, 20 August
Light rain. High 76°, low 65°.
Pressure29.91 inHg
Wind10.1 mph N
Humidity79%
Visibility—
Dew point67°
Fri, 2179° / 62°0.02
79 °
Boulder Hill, Friday, 21 August
Light rain. High 79°, low 62°.
Pressure29.97 inHg
Wind6.9 mph NE
Humidity64%
Visibility—
Dew point62°
Sat, 2273° / 58°0.02
73 °
Boulder Hill, Saturday, 22 August
Light rain. High 73°, low 58°.
Pressure29.94 inHg
Wind16.9 mph NE
Humidity82%
Visibility—
Dew point65°
Sun, 2367° / 52°0
67 °
Boulder Hill, Sunday, 23 August
Clear. High 67°, low 52°.
Pressure30.24 inHg
Wind11.6 mph NE
Humidity53%
Visibility—
Dew point47°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2480° / 64°0.13
80 °
Boulder Hill, Monday, 24 August
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.13 in
Chance of precipitation33%
Record high98° (2023)
Record low53° (1967)
Tue, 2581° / 64°0.09
81 °
Boulder Hill, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high81°
Average low64°
Average precipitation0.09 in
Chance of precipitation28%
Record high92° (2003)
Record low52° (2017)
Wed, 2681° / 65°0.18
81 °
Boulder Hill, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.18 in
Chance of precipitation35%
Record high95° (2024)
Record low49° (1964)
Thu, 2781° / 65°0.13
81 °
Boulder Hill, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.13 in
Chance of precipitation27%
Record high96° (2024)
Record low52° (2025)
Fri, 2880° / 65°0.13
80 °
Boulder Hill, Friday, 28 August
Climate normal for this date — 60-year average.
Average high80°
Average low65°
Average precipitation0.13 in
Chance of precipitation35%
Record high92° (1984)
Record low47° (1986)
Sat, 2980° / 64°0.14
80 °
Boulder Hill, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.14 in
Chance of precipitation30%
Record high94° (1984)
Record low44° (1965)
Sun, 3079° / 63°0.08
79 °
Boulder Hill, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.08 in
Chance of precipitation28%
Record high93° (2013)
Record low50° (1986)
Mon, 3179° / 63°0.08
79 °
Boulder Hill, Monday, 31 August
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.08 in
Chance of precipitation18%
Record high89° (2012)
Record low50° (2009)
Tue, 0179° / 62°0.13
79 °
Boulder Hill, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.13 in
Chance of precipitation32%
Record high93° (2011)
Record low46° (2009)
Wed, 0279° / 63°0.05
79 °
Boulder Hill, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.05 in
Chance of precipitation22%
Record high92° (2008)
Record low47° (1965)
Thu, 0379° / 63°0.09
79 °
Boulder Hill, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.09 in
Chance of precipitation28%
Record high93° (2023)
Record low47° (1974)
Fri, 0478° / 62°0.1
78 °
Boulder Hill, Friday, 4 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.1 in
Chance of precipitation28%
Record high92° (2023)
Record low46° (1974)
Sat, 0578° / 61°0.07
78 °
Boulder Hill, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high78°
Average low61°
Average precipitation0.07 in
Chance of precipitation20%
Record high90° (2023)
Record low49° (2010)
Sun, 0677° / 61°0.1
77 °
Boulder Hill, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high77°
Average low61°
Average precipitation0.1 in
Chance of precipitation38%
Record high91° (1990)
Record low46° (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 Boulder Hill, 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 Boulder Hill, 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.