Monthly outlook for Port Byron, IL: average high 54.7°, average low 39°. That is 3.7° above the climate normal for November. Precipitation is expected on 1 day (about 0.1 inches), against a normal of 4 days and 1.1 inches. The warmest day looks like 16 November (61.9°), the coolest 14 November (27.9°).
54.7°/39°
Average high / low
+3.7°
Above normal
1 / 4
Wet days / normal
0.1 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
7 November – 16 November
54.1°
48.9°
+2.9°
17 November – 26 November
55.7°
45.3°
+5.8°
27 November – 6 December
at normal
38.9°
—
November records over 66 years
76.5°1 November 2000All-time high
-3.6°26 November 1977All-time low
Climate normals and records are computed from the nearest reference point — Princeton (4 mi).
Sun, 0860° / 39°0
60 °
Port Byron, Sunday, 8 November
Clear. High 60°, low 39°.
Pressure30.06 inHg
Wind9.9 mph W
Humidity53%
Visibility6.2 mi
Dew point42°
Mon, 0960° / 38°0
60 °
Port Byron, Monday, 9 November
Partly cloudy. High 60°, low 38°.
Pressure30.15 inHg
Wind6.8 mph SW
Humidity54%
Visibility6.2 mi
Dew point41°
Tue, 1061° / 45°0
61 °
Port Byron, Tuesday, 10 November
Clear. High 61°, low 45°.
Pressure30.06 inHg
Wind3 mph NW
Humidity57%
Visibility6.2 mi
Dew point44°
Wed, 1155° / 42°0.06
55 °
Port Byron, Wednesday, 11 November
Light rain. High 55°, low 42°.
Pressure29.83 inHg
Wind7.8 mph N
Humidity92%
Visibility—
Dew point48°
Thu, 1247° / 38°0.02
47 °
Port Byron, Thursday, 12 November
Light rain. High 47°, low 38°.
Pressure30.00 inHg
Wind15.1 mph N
Humidity56%
Visibility—
Dew point31°
Fri, 1340° / 29°0.02
40 °
Port Byron, Friday, 13 November
Light snow. High 40°, low 29°.
Pressure30.15 inHg
Wind14.8 mph N
Humidity47%
Visibility—
Dew point19°
Sat, 1446° / 28°0
46 °
Port Byron, Saturday, 14 November
Mostly clear. High 46°, low 28°.
Pressure30.12 inHg
Wind9.2 mph SW
Humidity40%
Visibility—
Dew point19°
Sun, 1557° / 36°0
57 °
Port Byron, Sunday, 15 November
Clear. High 57°, low 36°.
Pressure30.06 inHg
Wind7 mph SW
Humidity57%
Visibility—
Dew point37°
Mon, 1662° / 45°0
62 °
Port Byron, Monday, 16 November
Overcast. High 62°, low 45°.
Pressure30.09 inHg
Wind9.5 mph SW
Humidity67%
Visibility—
Dew point49°
Tue, 1758° / 49°0
58 °
Port Byron, Tuesday, 17 November
Partly cloudy. High 58°, low 49°.
Pressure30.09 inHg
Wind11.7 mph S
Humidity72%
Visibility—
Dew point47°
Wed, 1859° / 46°0.04
59 °
Port Byron, Wednesday, 18 November
Light rain. High 59°, low 46°.
Pressure30.06 inHg
Wind9.2 mph N
Humidity65%
Visibility—
Dew point46°
Thu, 1955° / 41°0
55 °
Port Byron, Thursday, 19 November
Overcast. High 55°, low 41°.
Pressure30.36 inHg
Wind7.5 mph N
Humidity54%
Visibility—
Dew point36°
Fri, 2055° / 42°0
55 °
Port Byron, Friday, 20 November
Overcast. High 55°, low 42°.
Pressure30.27 inHg
Wind10.5 mph W
Humidity55%
Visibility—
Dew point37°
Sat, 2153° / 38°0
53 °
Port Byron, Saturday, 21 November
Clear. High 53°, low 38°.
Pressure30.45 inHg
Wind8.8 mph NW
Humidity39%
Visibility—
Dew point26°
Sun, 2255° / 37°0
55 °
Port Byron, Sunday, 22 November
Clear. High 55°, low 37°.
Pressure30.33 inHg
Wind13.5 mph W
Humidity35%
Visibility—
Dew point25°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2344° / 31°0.08
44 °
Port Byron, Monday, 23 November
Climate normal for this date — 60-year average.
Average high44°
Average low31°
Average precipitation0.08 in
Chance of precipitation30%
Record high65° (1966)
Record low11° (1970)
Tue, 2443° / 29°0.08
43 °
Port Byron, Tuesday, 24 November
Climate normal for this date — 60-year average.
Average high43°
Average low29°
Average precipitation0.08 in
Chance of precipitation25%
Record high64° (1966)
Record low8° (1985)
Wed, 2543° / 30°0.07
43 °
Port Byron, Wednesday, 25 November
Climate normal for this date — 60-year average.
Average high43°
Average low30°
Average precipitation0.07 in
Chance of precipitation27%
Record high59° (2006)
Record low5° (1977)
Thu, 2644° / 29°0.11
44 °
Port Byron, Thursday, 26 November
Climate normal for this date — 60-year average.
Average high44°
Average low29°
Average precipitation0.11 in
Chance of precipitation40%
Record high65° (1965)
Record low-4° (1977)
Fri, 2741° / 29°0.15
41 °
Port Byron, Friday, 27 November
Climate normal for this date — 60-year average.
Average high41°
Average low29°
Average precipitation0.15 in
Chance of precipitation52%
Record high66° (1990)
Record low11° (2018)
Sat, 2839° / 26°0.1
39 °
Port Byron, Saturday, 28 November
Climate normal for this date — 60-year average.
Average high39°
Average low26°
Average precipitation0.1 in
Chance of precipitation25%
Record high66° (2006)
Record low5° (2018)
Sun, 2941° / 28°0.07
41 °
Port Byron, Sunday, 29 November
Climate normal for this date — 60-year average.
Average high41°
Average low28°
Average precipitation0.07 in
Chance of precipitation32%
Record high66° (1998)
Record low1° (1976)
Mon, 3040° / 27°0.07
40 °
Port Byron, Monday, 30 November
Climate normal for this date — 60-year average.
Average high40°
Average low27°
Average precipitation0.07 in
Chance of precipitation22%
Record high66° (1998)
Record low7° (1977)
Tue, 0138° / 26°0.12
38 °
Port Byron, Tuesday, 1 December
Climate normal for this date — 60-year average.
Average high38°
Average low26°
Average precipitation0.12 in
Chance of precipitation38%
Record high60° (1970)
Record low6° (1971)
Wed, 0240° / 26°0.04
40 °
Port Byron, Wednesday, 2 December
Climate normal for this date — 60-year average.
Average high40°
Average low26°
Average precipitation0.04 in
Chance of precipitation25%
Record high67° (1982)
Record low0° (1985)
Thu, 0338° / 25°0.09
38 °
Port Byron, Thursday, 3 December
Climate normal for this date — 60-year average.
Average high38°
Average low25°
Average precipitation0.09 in
Chance of precipitation33%
Record high68° (2012)
Record low-7° (1985)
Fri, 0438° / 25°0.06
38 °
Port Byron, Friday, 4 December
Climate normal for this date — 60-year average.
Average high38°
Average low25°
Average precipitation0.06 in
Chance of precipitation20%
Record high68° (1998)
Record low-6° (1991)
Sat, 0538° / 24°0.07
38 °
Port Byron, Saturday, 5 December
Climate normal for this date — 60-year average.
Average high38°
Average low24°
Average precipitation0.07 in
Chance of precipitation33%
Record high67° (2001)
Record low1° (1991)
Sun, 0636° / 23°0.06
36 °
Port Byron, Sunday, 6 December
Climate normal for this date — 60-year average.
Average high36°
Average low23°
Average precipitation0.06 in
Chance of precipitation32%
Record high60° (1998)
Record low-3° (1964)
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 Port 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 Port 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.