Monthly outlook for Alta, IL: average high 81.5°, average low 64.2°. That is 0.1° below the climate normal for August. Precipitation is expected on 7 days (about 1.0 inches), against a normal of 5 days and 1.8 inches. The warmest day looks like 9 August (92.6°), the coolest 23 August (48.2°).
81.5°/64.2°
Average high / low
−0.1°
Below normal
7 / 5
Wet days / normal
1.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
81.9°
81.6°
+0.2°
18 August – 27 August
80.7°
81.7°
-0.5°
28 August – 6 September
at normal
80.2°
—
August records over 66 years
97.7°1 August 1988All-time high
47.1°29 August 1986All-time low
Climate normals and records are computed from the nearest reference point — Peoria (4 mi).
Sun, 0993° / 68°0
93 °
Alta, Sunday, 9 August
Overcast. High 93°, low 68°.
Pressure29.91 inHg
Wind14.7 mph SW
Humidity65%
Visibility6.2 mi
Dew point75°
Mon, 1090° / 76°0
90 °
Alta, Monday, 10 August
Overcast. High 90°, low 76°.
Pressure29.88 inHg
Wind12.7 mph W
Humidity58%
Visibility6.2 mi
Dew point72°
Tue, 1189° / 71°0.04
89 °
Alta, Tuesday, 11 August
Light rain. High 89°, low 71°.
Pressure29.80 inHg
Wind9.7 mph SW
Humidity57%
Visibility6.2 mi
Dew point71°
Wed, 1281° / 68°0.04
81 °
Alta, Wednesday, 12 August
Light rain. High 81°, low 68°.
Pressure29.88 inHg
Wind10.3 mph NE
Humidity77%
Visibility6.2 mi
Dew point70°
Thu, 1370° / 66°0.35
70 °
Alta, Thursday, 13 August
Rain. High 70°, low 66°.
Pressure29.91 inHg
Wind10.9 mph NE
Humidity95%
Visibility—
Dew point68°
Fri, 1475° / 55°0
75 °
Alta, Friday, 14 August
Clear. High 75°, low 55°.
Pressure30.18 inHg
Wind8 mph NE
Humidity58%
Visibility—
Dew point56°
Sat, 1575° / 55°0
75 °
Alta, Saturday, 15 August
Overcast. High 75°, low 55°.
Pressure30.30 inHg
Wind7.9 mph SE
Humidity54%
Visibility—
Dew point54°
Sun, 1681° / 57°0
81 °
Alta, Sunday, 16 August
Overcast. High 81°, low 57°.
Pressure30.18 inHg
Wind13.3 mph S
Humidity69%
Visibility—
Dew point59°
Mon, 1781° / 66°0.04
81 °
Alta, Monday, 17 August
Light rain. High 81°, low 66°.
Pressure29.94 inHg
Wind9.2 mph S
Humidity80%
Visibility—
Dew point71°
Tue, 1884° / 70°0.01
84 °
Alta, Tuesday, 18 August
Light rain. High 84°, low 70°.
Pressure30.00 inHg
Wind7.7 mph NE
Humidity65%
Visibility—
Dew point69°
Wed, 1989° / 67°0.16
89 °
Alta, Wednesday, 19 August
Light rain. High 89°, low 67°.
Pressure29.91 inHg
Wind7.9 mph S
Humidity59%
Visibility—
Dew point69°
Thu, 2081° / 67°0.29
81 °
Alta, Thursday, 20 August
Rain. High 81°, low 67°.
Pressure29.88 inHg
Wind10.6 mph N
Humidity65%
Visibility—
Dew point66°
Fri, 2181° / 62°0
81 °
Alta, Friday, 21 August
Clear. High 81°, low 62°.
Pressure29.97 inHg
Wind7.8 mph NE
Humidity59%
Visibility—
Dew point62°
Sat, 2281° / 61°0
81 °
Alta, Saturday, 22 August
Partly cloudy. High 81°, low 61°.
Pressure29.91 inHg
Wind18.2 mph NE
Humidity59%
Visibility—
Dew point63°
Sun, 2369° / 48°0
69 °
Alta, Sunday, 23 August
Mostly clear. High 69°, low 48°.
Pressure30.21 inHg
Wind13.5 mph E
Humidity46%
Visibility—
Dew point43°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2482° / 65°0.1
82 °
Alta, Monday, 24 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.1 in
Chance of precipitation32%
Record high97° (2023)
Record low53° (1966)
Tue, 2582° / 65°0.1
82 °
Alta, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.1 in
Chance of precipitation33%
Record high94° (2014)
Record low54° (1966)
Wed, 2682° / 66°0.14
82 °
Alta, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high82°
Average low66°
Average precipitation0.14 in
Chance of precipitation35%
Record high92° (2003)
Record low53° (1964)
Thu, 2782° / 66°0.09
82 °
Alta, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high82°
Average low66°
Average precipitation0.09 in
Chance of precipitation23%
Record high94° (2024)
Record low54° (1968)
Fri, 2882° / 65°0.12
82 °
Alta, Friday, 28 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.12 in
Chance of precipitation27%
Record high93° (2013)
Record low49° (1986)
Sat, 2982° / 65°0.11
82 °
Alta, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.11 in
Chance of precipitation35%
Record high94° (1984)
Record low47° (1986)
Sun, 3081° / 65°0.06
81 °
Alta, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.06 in
Chance of precipitation28%
Record high96° (2013)
Record low52° (1986)
Mon, 3180° / 64°0.08
80 °
Alta, Monday, 31 August
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.08 in
Chance of precipitation23%
Record high92° (2011)
Record low50° (2009)
Tue, 0180° / 64°0.17
80 °
Alta, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.17 in
Chance of precipitation28%
Record high98° (2011)
Record low48° (1967)
Wed, 0280° / 64°0.06
80 °
Alta, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.06 in
Chance of precipitation22%
Record high95° (2011)
Record low49° (1967)
Thu, 0380° / 64°0.09
80 °
Alta, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.09 in
Chance of precipitation28%
Record high92° (1964)
Record low47° (1974)
Fri, 0479° / 62°0.11
79 °
Alta, Friday, 4 September
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.11 in
Chance of precipitation32%
Record high91° (2007)
Record low44° (1974)
Sat, 0579° / 62°0.04
79 °
Alta, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.04 in
Chance of precipitation17%
Record high92° (1990)
Record low50° (1974)
Sun, 0678° / 62°0.1
78 °
Alta, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.1 in
Chance of precipitation33%
Record high92° (2015)
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 Alta, 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 Alta, 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.