Monthly outlook for Byron, IL: average high 62.5°, average low 49.3°. That is 1.7° above the climate normal for October. Precipitation is expected on 4 days (about 2.1 inches), against a normal of 5 days and 1.6 inches. The warmest day looks like 12 October (81.2°), the coolest 18 October (30.2°).
62.5°/49.3°
Average high / low
+1.7°
Above normal
4 / 5
Wet days / normal
2.1 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
10 October – 19 October
65.1°
60.4°
+2.6°
20 October – 29 October
58.2°
56.7°
+0.8°
30 October – 8 November
at normal
52.3°
—
October records over 66 years
88°3 October 2025All-time high
22.1°30 October 1988All-time low
Climate normals and records are computed from the nearest reference point — Rockford (14 mi).
Sun, 1177° / 57°0
77 °
Byron, Sunday, 11 October
Clear. High 77°, low 57°.
Pressure29.94 inHg
Wind6 mph S
Humidity63%
Visibility6.2 mi
Dew point58°
Mon, 1281° / 63°0
81 °
Byron, Monday, 12 October
Clear. High 81°, low 63°.
Pressure29.80 inHg
Wind12.4 mph SW
Humidity59%
Visibility6.2 mi
Dew point62°
Tue, 1373° / 66°0
73 °
Byron, Tuesday, 13 October
Overcast. High 73°, low 66°.
Pressure29.85 inHg
Wind9.3 mph NW
Humidity76%
Visibility6.2 mi
Dew point63°
Wed, 1466° / 58°0.07
66 °
Byron, Wednesday, 14 October
Light rain. High 66°, low 58°.
Pressure30.12 inHg
Wind11.6 mph N
Humidity71%
Visibility—
Dew point55°
Thu, 1563° / 52°0.06
63 °
Byron, Thursday, 15 October
Light rain. High 63°, low 52°.
Pressure30.30 inHg
Wind11.7 mph E
Humidity62%
Visibility—
Dew point47°
Fri, 1661° / 44°0.01
61 °
Byron, Friday, 16 October
Light rain. High 61°, low 44°.
Pressure29.83 inHg
Wind25.3 mph W
Humidity59%
Visibility—
Dew point42°
Sat, 1744° / 34°0.03
44 °
Byron, Saturday, 17 October
Snow. High 44°, low 34°.
Pressure30.36 inHg
Wind21.8 mph W
Humidity54%
Visibility—
Dew point26°
Sun, 1850° / 30°0
50 °
Byron, Sunday, 18 October
Clear. High 50°, low 30°.
Pressure30.39 inHg
Wind15.5 mph S
Humidity35%
Visibility—
Dew point19°
Mon, 1959° / 38°0
59 °
Byron, Monday, 19 October
Clear. High 59°, low 38°.
Pressure30.33 inHg
Wind8.2 mph S
Humidity43%
Visibility—
Dew point32°
Tue, 2063° / 47°0.02
63 °
Byron, Tuesday, 20 October
Light rain. High 63°, low 47°.
Pressure30.21 inHg
Wind15.9 mph S
Humidity37%
Visibility—
Dew point32°
Wed, 2162° / 49°0.94
62 °
Byron, Wednesday, 21 October
Heavy rain. High 62°, low 49°.
Pressure30.00 inHg
Wind15.2 mph SE
Humidity62%
Visibility—
Dew point47°
Thu, 2259° / 55°0.95
59 °
Byron, Thursday, 22 October
Rain. High 59°, low 55°.
Pressure29.65 inHg
Wind13.9 mph NW
Humidity89%
Visibility—
Dew point56°
Fri, 2362° / 53°0
62 °
Byron, Friday, 23 October
Overcast. High 62°, low 53°.
Pressure29.94 inHg
Wind12.6 mph NW
Humidity79%
Visibility—
Dew point52°
Sat, 2454° / 47°0
54 °
Byron, Saturday, 24 October
Overcast. High 54°, low 47°.
Pressure29.94 inHg
Wind16.9 mph W
Humidity67%
Visibility—
Dew point41°
Sun, 2550° / 37°0
50 °
Byron, Sunday, 25 October
Overcast. High 50°, low 37°.
Pressure29.94 inHg
Wind9.7 mph W
Humidity53%
Visibility—
Dew point31°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2655° / 42°0.11
55 °
Byron, Monday, 26 October
Climate normal for this date — 60-year average.
Average high55°
Average low42°
Average precipitation0.11 in
Chance of precipitation28%
Record high77° (1963)
Record low24° (1962)
Tue, 2755° / 41°0.07
55 °
Byron, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high55°
Average low41°
Average precipitation0.07 in
Chance of precipitation22%
Record high74° (2014)
Record low26° (1997)
Wed, 2855° / 41°0.04
55 °
Byron, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high55°
Average low41°
Average precipitation0.04 in
Chance of precipitation20%
Record high71° (1999)
Record low25° (1976)
Thu, 2955° / 40°0.06
55 °
Byron, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high55°
Average low40°
Average precipitation0.06 in
Chance of precipitation22%
Record high78° (2024)
Record low23° (1980)
Fri, 3056° / 41°0.09
56 °
Byron, Friday, 30 October
Climate normal for this date — 60-year average.
Average high56°
Average low41°
Average precipitation0.09 in
Chance of precipitation28%
Record high76° (2024)
Record low22° (1988)
Sat, 3155° / 42°0.1
55 °
Byron, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high55°
Average low42°
Average precipitation0.1 in
Chance of precipitation43%
Record high72° (1974)
Record low27° (1988)
Sun, 0154° / 40°0.16
54 °
Byron, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high54°
Average low40°
Average precipitation0.16 in
Chance of precipitation35%
Record high73° (2000)
Record low18° (2019)
Mon, 0253° / 39°0.1
53 °
Byron, Monday, 2 November
Climate normal for this date — 60-year average.
Average high53°
Average low39°
Average precipitation0.1 in
Chance of precipitation35%
Record high73° (1961)
Record low21° (1991)
Tue, 0352° / 38°0.06
52 °
Byron, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high52°
Average low38°
Average precipitation0.06 in
Chance of precipitation28%
Record high71° (1964)
Record low15° (1991)
Wed, 0452° / 39°0.09
52 °
Byron, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high52°
Average low39°
Average precipitation0.09 in
Chance of precipitation25%
Record high70° (2015)
Record low13° (1991)
Thu, 0551° / 38°0.11
51 °
Byron, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high51°
Average low38°
Average precipitation0.11 in
Chance of precipitation25%
Record high70° (1978)
Record low18° (1991)
Fri, 0651° / 37°0.09
51 °
Byron, Friday, 6 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.09 in
Chance of precipitation28%
Record high70° (1975)
Record low21° (1991)
Sat, 0750° / 36°0.03
50 °
Byron, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high50°
Average low36°
Average precipitation0.03 in
Chance of precipitation17%
Record high67° (2020)
Record low10° (1991)
Sun, 0850° / 36°0.05
50 °
Byron, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high50°
Average low36°
Average precipitation0.05 in
Chance of precipitation20%
Record high71° (2020)
Record low13° (1991)
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 Byron, 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 Byron, 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.