Monthly outlook for Big Rock, IL: average high 59°, average low 42.9°. That is 1.5° above the climate normal for October. Precipitation is expected on 2 days (about 0.2 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 22 October (74°), the coolest 29 October (36.5°).
59°/42.9°
Average high / low
+1.5°
Above normal
2 / 5
Wet days / normal
0.2 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
21 October – 30 October
62.4°
57.7°
+2.6°
31 October – 9 November
53.4°
53.2°
+0.1°
10 November – 19 November
at normal
47.8°
—
October records over 66 years
87.6°3 October 2025All-time high
21.9°24 October 1981All-time low
Climate normals and records are computed from the nearest reference point — Boulder Hill (11 mi).
Thu, 2274° / 45°0
74 °
Big Rock, Thursday, 22 October
Clear. High 74°, low 45°.
Pressure30.27 inHg
Wind2.3 mph E
Humidity56%
Visibility6.2 mi
Dew point52°
Fri, 2369° / 54°0
69 °
Big Rock, Friday, 23 October
Clear. High 69°, low 54°.
Pressure30.36 inHg
Wind5 mph SE
Humidity64%
Visibility6.2 mi
Dew point52°
Sat, 2468° / 49°0
68 °
Big Rock, Saturday, 24 October
Overcast. High 68°, low 49°.
Pressure30.36 inHg
Wind8.6 mph S
Humidity62%
Visibility6.2 mi
Dew point50°
Sun, 2571° / 50°0
71 °
Big Rock, Sunday, 25 October
Overcast. High 71°, low 50°.
Pressure30.36 inHg
Wind6.9 mph S
Humidity52%
Visibility—
Dew point48°
Mon, 2669° / 45°0.02
69 °
Big Rock, Monday, 26 October
Light rain. High 69°, low 45°.
Pressure30.18 inHg
Wind14.3 mph N
Humidity54%
Visibility—
Dew point49°
Tue, 2748° / 39°0.08
48 °
Big Rock, Tuesday, 27 October
Light rain. High 48°, low 39°.
Pressure30.39 inHg
Wind15.3 mph N
Humidity59%
Visibility—
Dew point33°
Wed, 2848° / 37°0
48 °
Big Rock, Wednesday, 28 October
Overcast. High 48°, low 37°.
Pressure30.33 inHg
Wind7.5 mph N
Humidity50%
Visibility—
Dew point29°
Thu, 2952° / 36°0
52 °
Big Rock, Thursday, 29 October
Mostly clear. High 52°, low 36°.
Pressure30.21 inHg
Wind8.7 mph NW
Humidity48%
Visibility—
Dew point30°
Fri, 3053° / 37°0
53 °
Big Rock, Friday, 30 October
Clear. High 53°, low 37°.
Pressure30.24 inHg
Wind7.1 mph SE
Humidity43%
Visibility—
Dew point28°
Sat, 3159° / 40°0
59 °
Big Rock, Saturday, 31 October
Clear. High 59°, low 40°.
Pressure30.00 inHg
Wind14.8 mph S
Humidity38%
Visibility—
Dew point30°
Sun, 0154° / 46°0.11
54 °
Big Rock, Sunday, 1 November
Light rain. High 54°, low 46°.
Pressure29.97 inHg
Wind11.6 mph S
Humidity93%
Visibility—
Dew point48°
Mon, 0258° / 45°0
58 °
Big Rock, Monday, 2 November
Clear. High 58°, low 45°.
Pressure30.12 inHg
Wind12.8 mph NW
Humidity35%
Visibility—
Dew point29°
Tue, 0349° / 37°0
49 °
Big Rock, Tuesday, 3 November
Overcast. High 49°, low 37°.
Pressure30.33 inHg
Wind8.2 mph N
Humidity43%
Visibility—
Dew point25°
Wed, 0449° / 43°0
49 °
Big Rock, Wednesday, 4 November
Overcast. High 49°, low 43°.
Pressure30.18 inHg
Wind8.3 mph E
Humidity56%
Visibility—
Dew point33°
Thu, 0553° / 41°0
53 °
Big Rock, Thursday, 5 November
Mostly clear. High 53°, low 41°.
Pressure30.39 inHg
Wind9.2 mph E
Humidity37%
Visibility—
Dew point26°
From day 17 onward the outlook is built from 60-year climate statistics
Fri, 0653° / 37°0.07
53 °
Big Rock, Friday, 6 November
Climate normal for this date — 60-year average.
Average high53°
Average low37°
Average precipitation0.07 in
Chance of precipitation27%
Record high72° (1975)
Record low23° (1991)
Sat, 0752° / 37°0.05
52 °
Big Rock, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high52°
Average low37°
Average precipitation0.05 in
Chance of precipitation20%
Record high69° (2020)
Record low16° (1991)
Sun, 0851° / 37°0.06
51 °
Big Rock, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.06 in
Chance of precipitation20%
Record high74° (2020)
Record low12° (1991)
Mon, 0952° / 38°0.11
52 °
Big Rock, Monday, 9 November
Climate normal for this date — 60-year average.
Average high52°
Average low38°
Average precipitation0.11 in
Chance of precipitation33%
Record high73° (1999)
Record low16° (1991)
Tue, 1050° / 37°0.12
50 °
Big Rock, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high50°
Average low37°
Average precipitation0.12 in
Chance of precipitation38%
Record high72° (2020)
Record low17° (2017)
Wed, 1148° / 34°0.06
48 °
Big Rock, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high48°
Average low34°
Average precipitation0.06 in
Chance of precipitation27%
Record high71° (1964)
Record low16° (2019)
Thu, 1247° / 33°0.06
47 °
Big Rock, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high47°
Average low33°
Average precipitation0.06 in
Chance of precipitation23%
Record high67° (1964)
Record low6° (2019)
Fri, 1347° / 33°0.05
47 °
Big Rock, Friday, 13 November
Climate normal for this date — 60-year average.
Average high47°
Average low33°
Average precipitation0.05 in
Chance of precipitation20%
Record high70° (1999)
Record low2° (2019)
Sat, 1448° / 33°0.07
48 °
Big Rock, Saturday, 14 November
Climate normal for this date — 60-year average.
Average high48°
Average low33°
Average precipitation0.07 in
Chance of precipitation32%
Record high70° (1971)
Record low13° (1986)
Sun, 1547° / 34°0.09
47 °
Big Rock, Sunday, 15 November
Climate normal for this date — 60-year average.
Average high47°
Average low34°
Average precipitation0.09 in
Chance of precipitation27%
Record high69° (2025)
Record low18° (1982)
Mon, 1647° / 33°0.05
47 °
Big Rock, Monday, 16 November
Climate normal for this date — 60-year average.
Average high47°
Average low33°
Average precipitation0.05 in
Chance of precipitation15%
Record high64° (1971)
Record low20° (1997)
Tue, 1748° / 34°0.1
48 °
Big Rock, Tuesday, 17 November
Climate normal for this date — 60-year average.
Average high48°
Average low34°
Average precipitation0.1 in
Chance of precipitation27%
Record high71° (2016)
Record low15° (2014)
Wed, 1848° / 35°0.13
48 °
Big Rock, Wednesday, 18 November
Climate normal for this date — 60-year average.
Average high48°
Average low35°
Average precipitation0.13 in
Chance of precipitation28%
Record high68° (1999)
Record low11° (2014)
Thu, 1947° / 34°0.07
47 °
Big Rock, Thursday, 19 November
Climate normal for this date — 60-year average.
Average high47°
Average low34°
Average precipitation0.07 in
Chance of precipitation32%
Record high65° (1985)
Record low17° (2014)
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 Big Rock, 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 Big Rock, 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.