Monthly outlook for Riley, IL: average high 64.9°, average low 48.3°. That is 4.5° above the climate normal for October. Precipitation is expected on 2 days (about 0.2 inches), against a normal of 5 days and 1.5 inches. The warmest day looks like 1 November (75°), the coolest 26 October (37°).
64.9°/48.3°
Average high / low
+4.5°
Above normal
2 / 5
Wet days / normal
0.2 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
18 October – 27 October
63°
57.9°
+2.9°
28 October – 6 November
68.1°
53.8°
+8°
7 November – 16 November
at normal
48°
—
October records over 66 years
87.1°3 October 2025All-time high
22.1°24 October 1981All-time low
Climate normals and records are computed from the nearest reference point — Sycamore (14 mi).
Mon, 1966° / 43°0
66 °
Riley, Monday, 19 October
Mostly clear. High 66°, low 43°.
Pressure30.39 inHg
Wind3.9 mph SW
Humidity56%
Visibility6.2 mi
Dew point45°
Tue, 2065° / 42°0
65 °
Riley, Tuesday, 20 October
Clear. High 65°, low 42°.
Pressure30.39 inHg
Wind4.2 mph SE
Humidity58%
Visibility6.2 mi
Dew point48°
Wed, 2167° / 44°0
67 °
Riley, Wednesday, 21 October
Clear. High 67°, low 44°.
Pressure30.30 inHg
Wind4.3 mph SW
Humidity52%
Visibility6.2 mi
Dew point47°
Thu, 2268° / 51°0
68 °
Riley, Thursday, 22 October
Mostly clear. High 68°, low 51°.
Pressure30.30 inHg
Wind9.7 mph NE
Humidity58%
Visibility—
Dew point51°
Fri, 2364° / 47°0
64 °
Riley, Friday, 23 October
Partly cloudy. High 64°, low 47°.
Pressure30.36 inHg
Wind9.1 mph SE
Humidity59%
Visibility—
Dew point47°
Sat, 2470° / 56°0
70 °
Riley, Saturday, 24 October
Overcast. High 70°, low 56°.
Pressure30.18 inHg
Wind17.3 mph S
Humidity40%
Visibility—
Dew point41°
Sun, 2557° / 42°0.01
57 °
Riley, Sunday, 25 October
Light rain. High 57°, low 42°.
Pressure30.45 inHg
Wind13.4 mph NW
Humidity33%
Visibility—
Dew point24°
Mon, 2655° / 37°0
55 °
Riley, Monday, 26 October
Partly cloudy. High 55°, low 37°.
Pressure30.36 inHg
Wind10.9 mph SW
Humidity31%
Visibility—
Dew point22°
Tue, 2755° / 48°0.11
55 °
Riley, Tuesday, 27 October
Light rain. High 55°, low 48°.
Pressure30.18 inHg
Wind9.8 mph SW
Humidity92%
Visibility—
Dew point49°
Wed, 2864° / 51°0
64 °
Riley, Wednesday, 28 October
Overcast. High 64°, low 51°.
Pressure29.94 inHg
Wind11.5 mph SW
Humidity57%
Visibility—
Dew point47°
Thu, 2966° / 52°0
66 °
Riley, Thursday, 29 October
Overcast. High 66°, low 52°.
Pressure29.77 inHg
Wind9.8 mph SW
Humidity56%
Visibility—
Dew point48°
Fri, 3069° / 52°0
69 °
Riley, Friday, 30 October
Clear. High 69°, low 52°.
Pressure29.74 inHg
Wind16.5 mph SW
Humidity58%
Visibility—
Dew point50°
Sat, 3172° / 56°0.08
72 °
Riley, Saturday, 31 October
Light rain. High 72°, low 56°.
Pressure29.71 inHg
Wind14.5 mph SW
Humidity66%
Visibility—
Dew point56°
Sun, 0175° / 61°0
75 °
Riley, Sunday, 1 November
Overcast. High 75°, low 61°.
Pressure29.88 inHg
Wind15.4 mph SW
Humidity57%
Visibility—
Dew point56°
Mon, 0263° / 49°0
63 °
Riley, Monday, 2 November
Clear. High 63°, low 49°.
Pressure30.27 inHg
Wind14.2 mph NE
Humidity41%
Visibility—
Dew point37°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0352° / 38°0.07
52 °
Riley, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high52°
Average low38°
Average precipitation0.07 in
Chance of precipitation28%
Record high72° (1964)
Record low16° (1991)
Wed, 0452° / 40°0.1
52 °
Riley, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high52°
Average low40°
Average precipitation0.1 in
Chance of precipitation25%
Record high71° (2015)
Record low14° (1991)
Thu, 0552° / 38°0.11
52 °
Riley, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high52°
Average low38°
Average precipitation0.11 in
Chance of precipitation27%
Record high73° (1978)
Record low17° (1991)
Fri, 0651° / 37°0.09
51 °
Riley, Friday, 6 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.09 in
Chance of precipitation27%
Record high71° (1975)
Record low22° (1991)
Sat, 0751° / 37°0.03
51 °
Riley, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.03 in
Chance of precipitation20%
Record high67° (2009)
Record low13° (1991)
Sun, 0851° / 37°0.05
51 °
Riley, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.05 in
Chance of precipitation13%
Record high72° (2020)
Record low12° (1991)
Mon, 0951° / 37°0.12
51 °
Riley, Monday, 9 November
Climate normal for this date — 60-year average.
Average high51°
Average low37°
Average precipitation0.12 in
Chance of precipitation33%
Record high73° (1999)
Record low17° (1991)
Tue, 1049° / 35°0.1
49 °
Riley, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high49°
Average low35°
Average precipitation0.1 in
Chance of precipitation33%
Record high72° (2022)
Record low15° (2017)
Wed, 1147° / 33°0.07
47 °
Riley, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high47°
Average low33°
Average precipitation0.07 in
Chance of precipitation25%
Record high70° (1964)
Record low13° (2019)
Thu, 1246° / 32°0.06
46 °
Riley, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high46°
Average low32°
Average precipitation0.06 in
Chance of precipitation23%
Record high65° (1964)
Record low1° (2019)
Fri, 1346° / 32°0.04
46 °
Riley, Friday, 13 November
Climate normal for this date — 60-year average.
Average high46°
Average low32°
Average precipitation0.04 in
Chance of precipitation20%
Record high70° (1999)
Record low1° (2019)
Sat, 1447° / 32°0.07
47 °
Riley, Saturday, 14 November
Climate normal for this date — 60-year average.
Average high47°
Average low32°
Average precipitation0.07 in
Chance of precipitation30%
Record high69° (1971)
Record low13° (1986)
Sun, 1546° / 33°0.08
46 °
Riley, Sunday, 15 November
Climate normal for this date — 60-year average.
Average high46°
Average low33°
Average precipitation0.08 in
Chance of precipitation23%
Record high69° (2025)
Record low14° (2019)
Mon, 1647° / 33°0.05
47 °
Riley, Monday, 16 November
Climate normal for this date — 60-year average.
Average high47°
Average low33°
Average precipitation0.05 in
Chance of precipitation15%
Record high63° (1988)
Record low18° (1997)
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 Riley, 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 Riley, 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.