As of 16:43 CDT

Weather in Port Byron, IL

77°Current weather

Port Byron, Sunday, 25 October, 16:43

Overcast. Feels like 77°. High 77°, low 52°.

Pressure30.30 inHg
Wind4 mph S
Humidity48%
Visibility6.2 mi
Dew point56°

Monthly outlook for Port Byron, IL: average high 62.9°, average low 50°. That is 4.7° above the climate normal for October. Precipitation is expected on 7 days (about 1.1 inches), against a normal of 4 days and 1.4 inches. The warmest day looks like 25 October (77.3°), the coolest 9 November (39.5°).

62.9°/50°
Average high / low
+4.7°
Above normal
7 / 4
Wet days / normal
1.1 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
25 October – 3 November65.9°55.9°+5.6°
4 November – 13 November58°50.4°+4.3°
14 November – 23 Novemberat normal46.6°—

October records over 66 years

88.2°3 October 2025All-time high
17.8°28 October 1967All-time low

Climate normals and records are computed from the nearest reference point — Princeton (4 mi).

Mon, 2670° / 53°0Overcast
70 °Overcast

Port Byron, Monday, 26 October

Overcast. High 70°, low 53°.

Pressure30.30 inHg
Wind5.9 mph E
Humidity75%
Visibility6.2 mi
Dew point55°
Tue, 2770° / 51°0Overcast
70 °Overcast

Port Byron, Tuesday, 27 October

Overcast. High 70°, low 51°.

Pressure30.21 inHg
Wind6.2 mph S
Humidity65%
Visibility6.2 mi
Dew point54°
Wed, 2870° / 55°0.11Light rain
70 °Light rain

Port Byron, Wednesday, 28 October

Light rain. High 70°, low 55°.

Pressure30.15 inHg
Wind7.1 mph S
Humidity70%
Visibility6.2 mi
Dew point53°
Thu, 2967° / 58°0.04Light rain
67 °Light rain

Port Byron, Thursday, 29 October

Light rain. High 67°, low 58°.

Pressure30.06 inHg
Wind7.5 mph SW
Humidity79%
Visibility6.2 mi
Dew point59°
Fri, 3066° / 51°0Overcast
66 °Overcast

Port Byron, Friday, 30 October

Overcast. High 66°, low 51°.

Pressure30.18 inHg
Wind4.8 mph SE
Humidity75%
Visibility—
Dew point54°
Sat, 3159° / 52°0.1Light rain
59 °Light rain

Port Byron, Saturday, 31 October

Light rain. High 59°, low 52°.

Pressure30.21 inHg
Wind11 mph SE
Humidity67%
Visibility—
Dew point46°
Sun, 0157° / 51°0.35Rain
57 °Rain

Port Byron, Sunday, 1 November

Rain. High 57°, low 51°.

Pressure30.18 inHg
Wind7.2 mph SE
Humidity93%
Visibility—
Dew point52°
Mon, 0260° / 51°0Overcast
60 °Overcast

Port Byron, Monday, 2 November

Overcast. High 60°, low 51°.

Pressure30.12 inHg
Wind9.3 mph E
Humidity77%
Visibility—
Dew point51°
Tue, 0362° / 50°0Overcast
62 °Overcast

Port Byron, Tuesday, 3 November

Overcast. High 62°, low 50°.

Pressure30.12 inHg
Wind10.9 mph SE
Humidity58%
Visibility—
Dew point45°
Wed, 0465° / 51°0Overcast
65 °Overcast

Port Byron, Wednesday, 4 November

Overcast. High 65°, low 51°.

Pressure30.03 inHg
Wind6.7 mph S
Humidity63%
Visibility—
Dew point47°
Thu, 0560° / 49°0.05Light rain
60 °Light rain

Port Byron, Thursday, 5 November

Light rain. High 60°, low 49°.

Pressure29.97 inHg
Wind7.5 mph N
Humidity56%
Visibility—
Dew point43°
Fri, 0658° / 43°0Overcast
58 °Overcast

Port Byron, Friday, 6 November

Overcast. High 58°, low 43°.

Pressure29.97 inHg
Wind8.2 mph E
Humidity55%
Visibility—
Dew point39°
Sat, 0759° / 48°0.28Rain
59 °Rain

Port Byron, Saturday, 7 November

Rain. High 59°, low 48°.

Pressure29.74 inHg
Wind14.2 mph S
Humidity95%
Visibility—
Dew point51°
Sun, 0859° / 47°0.06Light rain
59 °Light rain

Port Byron, Sunday, 8 November

Light rain. High 59°, low 47°.

Pressure29.68 inHg
Wind16.6 mph W
Humidity43%
Visibility—
Dew point35°
Mon, 0947° / 39°0.11Light rain
47 °Light rain

Port Byron, Monday, 9 November

Light rain. High 47°, low 39°.

Pressure29.56 inHg
Wind19.6 mph W
Humidity64%
Visibility—
Dew point35°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 1050° / 35°0.1Climate normal
50 °Climate normal

Port Byron, Tuesday, 10 November

Climate normal for this date — 60-year average.

Average high50°
Average low35°
Average precipitation0.1 in
Chance of precipitation28%
Record high73° (2022)
Record low15° (2018)
Wed, 1148° / 33°0.07Climate normal
48 °Climate normal

Port Byron, Wednesday, 11 November

Climate normal for this date — 60-year average.

Average high48°
Average low33°
Average precipitation0.07 in
Chance of precipitation22%
Record high72° (1964)
Record low15° (2019)
Thu, 1246° / 32°0.06Climate normal
46 °Climate normal

Port Byron, Thursday, 12 November

Climate normal for this date — 60-year average.

Average high46°
Average low32°
Average precipitation0.06 in
Chance of precipitation25%
Record high66° (1964)
Record low7° (2019)
Fri, 1347° / 32°0.05Climate normal
47 °Climate normal

Port Byron, Friday, 13 November

Climate normal for this date — 60-year average.

Average high47°
Average low32°
Average precipitation0.05 in
Chance of precipitation25%
Record high72° (1999)
Record low6° (1986)
Sat, 1448° / 33°0.06Climate normal
48 °Climate normal

Port Byron, Saturday, 14 November

Climate normal for this date — 60-year average.

Average high48°
Average low33°
Average precipitation0.06 in
Chance of precipitation28%
Record high70° (2025)
Record low14° (1986)
Sun, 1547° / 34°0.07Climate normal
47 °Climate normal

Port Byron, Sunday, 15 November

Climate normal for this date — 60-year average.

Average high47°
Average low34°
Average precipitation0.07 in
Chance of precipitation28%
Record high69° (2025)
Record low18° (1982)
Mon, 1648° / 33°0.06Climate normal
48 °Climate normal

Port Byron, Monday, 16 November

Climate normal for this date — 60-year average.

Average high48°
Average low33°
Average precipitation0.06 in
Chance of precipitation25%
Record high66° (1971)
Record low17° (1997)
Tue, 1748° / 34°0.13Climate normal
48 °Climate normal

Port Byron, Tuesday, 17 November

Climate normal for this date — 60-year average.

Average high48°
Average low34°
Average precipitation0.13 in
Chance of precipitation25%
Record high73° (2016)
Record low14° (2005)
Wed, 1848° / 34°0.07Climate normal
48 °Climate normal

Port Byron, Wednesday, 18 November

Climate normal for this date — 60-year average.

Average high48°
Average low34°
Average precipitation0.07 in
Chance of precipitation30%
Record high70° (1999)
Record low11° (2014)
Thu, 1948° / 33°0.06Climate normal
48 °Climate normal

Port Byron, Thursday, 19 November

Climate normal for this date — 60-year average.

Average high48°
Average low33°
Average precipitation0.06 in
Chance of precipitation27%
Record high66° (1979)
Record low16° (2022)
Fri, 2046° / 32°0.1Climate normal
46 °Climate normal

Port Byron, Friday, 20 November

Climate normal for this date — 60-year average.

Average high46°
Average low32°
Average precipitation0.1 in
Chance of precipitation32%
Record high65° (2003)
Record low16° (2022)
Sat, 2144° / 30°0.08Climate normal
44 °Climate normal

Port Byron, Saturday, 21 November

Climate normal for this date — 60-year average.

Average high44°
Average low30°
Average precipitation0.08 in
Chance of precipitation22%
Record high66° (1990)
Record low7° (1964)
Sun, 2245° / 30°0.03Climate normal
45 °Climate normal

Port Byron, Sunday, 22 November

Climate normal for this date — 60-year average.

Average high45°
Average low30°
Average precipitation0.03 in
Chance of precipitation15%
Record high67° (2010)
Record low4° (2015)
Mon, 2344° / 31°0.08Climate normal
44 °Climate normal

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)

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.