Monthly outlook for Summum, IL: average high 68.3°, average low 51.9°. That is 3.7° above the climate normal for October. Precipitation is expected on 4 days (about 2.9 inches), against a normal of 4 days and 1.4 inches. The warmest day looks like 27 October (77.6°), the coolest 17 October (38.4°).
68.3°/51.9°
Average high / low
+3.7°
Above normal
4 / 4
Wet days / normal
2.9 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
15 October – 24 October
67.1°
62.9°
+2.3°
25 October – 3 November
70.2°
58.9°
+6.3°
4 November – 13 November
at normal
53.7°
—
October records over 66 years
89.4°3 October 2006All-time high
26.1°26 October 1962All-time low
Climate normals and records are computed from the nearest reference point — Browning (11 mi).
Fri, 1656° / 48°0.03
56 °
Summum, Friday, 16 October
Light rain. High 56°, low 48°.
Pressure30.18 inHg
Wind16.8 mph NW
Humidity60%
Visibility6.2 mi
Dew point42°
Sat, 1758° / 38°0
58 °
Summum, Saturday, 17 October
Clear. High 58°, low 38°.
Pressure30.59 inHg
Wind1.3 mph S
Humidity43%
Visibility6.2 mi
Dew point31°
Sun, 1863° / 43°0
63 °
Summum, Sunday, 18 October
Clear. High 63°, low 43°.
Pressure30.45 inHg
Wind10.9 mph S
Humidity47%
Visibility6.2 mi
Dew point39°
Mon, 1966° / 44°0.01
66 °
Summum, Monday, 19 October
Light rain. High 66°, low 44°.
Pressure30.36 inHg
Wind6.8 mph S
Humidity50%
Visibility6.2 mi
Dew point42°
Tue, 2066° / 48°0.04
66 °
Summum, Tuesday, 20 October
Light rain. High 66°, low 48°.
Pressure30.30 inHg
Wind6.2 mph S
Humidity57%
Visibility—
Dew point47°
Wed, 2173° / 57°0
73 °
Summum, Wednesday, 21 October
Overcast. High 73°, low 57°.
Pressure30.30 inHg
Wind7 mph S
Humidity41%
Visibility—
Dew point46°
Thu, 2269° / 55°0
69 °
Summum, Thursday, 22 October
Overcast. High 69°, low 55°.
Pressure30.21 inHg
Wind8.2 mph S
Humidity42%
Visibility—
Dew point43°
Fri, 2375° / 56°0
75 °
Summum, Friday, 23 October
Overcast. High 75°, low 56°.
Pressure30.18 inHg
Wind13.4 mph SE
Humidity32%
Visibility—
Dew point40°
Sat, 2473° / 58°0
73 °
Summum, Saturday, 24 October
Overcast. High 73°, low 58°.
Pressure30.12 inHg
Wind15.9 mph SW
Humidity43%
Visibility—
Dew point47°
Sun, 2566° / 48°0
66 °
Summum, Sunday, 25 October
Clear. High 66°, low 48°.
Pressure30.50 inHg
Wind11.4 mph NE
Humidity32%
Visibility—
Dew point33°
Mon, 2670° / 45°0
70 °
Summum, Monday, 26 October
Overcast. High 70°, low 45°.
Pressure30.42 inHg
Wind8.8 mph S
Humidity45%
Visibility—
Dew point41°
Tue, 2778° / 59°0.01
78 °
Summum, Tuesday, 27 October
Light rain. High 78°, low 59°.
Pressure30.12 inHg
Wind14.7 mph SW
Humidity33%
Visibility—
Dew point44°
Wed, 2863° / 58°0.43
63 °
Summum, Wednesday, 28 October
Rain. High 63°, low 58°.
Pressure30.00 inHg
Wind13.6 mph S
Humidity89%
Visibility—
Dew point56°
Thu, 2969° / 61°0.32
69 °
Summum, Thursday, 29 October
Rain. High 69°, low 61°.
Pressure29.91 inHg
Wind12.8 mph S
Humidity77%
Visibility—
Dew point61°
Fri, 3076° / 56°1.79
76 °
Summum, Friday, 30 October
Heavy rain. High 76°, low 56°.
Pressure29.71 inHg
Wind22.7 mph W
Humidity70%
Visibility—
Dew point64°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 3159° / 45°0.17
59 °
Summum, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high59°
Average low45°
Average precipitation0.17 in
Chance of precipitation45%
Record high77° (1968)
Record low28° (1993)
Sun, 0159° / 44°0.18
59 °
Summum, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high59°
Average low44°
Average precipitation0.18 in
Chance of precipitation35%
Record high79° (2016)
Record low26° (2023)
Mon, 0257° / 43°0.08
57 °
Summum, Monday, 2 November
Climate normal for this date — 60-year average.
Average high57°
Average low43°
Average precipitation0.08 in
Chance of precipitation32%
Record high77° (1961)
Record low25° (1991)
Tue, 0356° / 42°0.11
56 °
Summum, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high56°
Average low42°
Average precipitation0.11 in
Chance of precipitation28%
Record high76° (1964)
Record low18° (1991)
Wed, 0456° / 43°0.08
56 °
Summum, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high56°
Average low43°
Average precipitation0.08 in
Chance of precipitation28%
Record high77° (1978)
Record low17° (1991)
Thu, 0555° / 41°0.15
55 °
Summum, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high55°
Average low41°
Average precipitation0.15 in
Chance of precipitation32%
Record high76° (1978)
Record low21° (1991)
Fri, 0655° / 40°0.1
55 °
Summum, Friday, 6 November
Climate normal for this date — 60-year average.
Average high55°
Average low40°
Average precipitation0.1 in
Chance of precipitation25%
Record high71° (2020)
Record low25° (1991)
Sat, 0755° / 40°0.03
55 °
Summum, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high55°
Average low40°
Average precipitation0.03 in
Chance of precipitation22%
Record high72° (1966)
Record low15° (1991)
Sun, 0855° / 40°0.04
55 °
Summum, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high55°
Average low40°
Average precipitation0.04 in
Chance of precipitation18%
Record high77° (1999)
Record low2° (1991)
Mon, 0956° / 41°0.12
56 °
Summum, Monday, 9 November
Climate normal for this date — 60-year average.
Average high56°
Average low41°
Average precipitation0.12 in
Chance of precipitation32%
Record high74° (1999)
Record low5° (1991)
Tue, 1053° / 39°0.17
53 °
Summum, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high53°
Average low39°
Average precipitation0.17 in
Chance of precipitation28%
Record high74° (2020)
Record low18° (2018)
Wed, 1152° / 37°0.06
52 °
Summum, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high52°
Average low37°
Average precipitation0.06 in
Chance of precipitation28%
Record high76° (1964)
Record low18° (2019)
Thu, 1250° / 35°0.06
50 °
Summum, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high50°
Average low35°
Average precipitation0.06 in
Chance of precipitation22%
Record high71° (2010)
Record low10° (2019)
Fri, 1351° / 36°0.06
51 °
Summum, Friday, 13 November
Climate normal for this date — 60-year average.
Average high51°
Average low36°
Average precipitation0.06 in
Chance of precipitation18%
Record high74° (1999)
Record low9° (1986)
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 Summum, 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 Summum, 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.