As of 18:20 CDT

Weather in Sullivan, IL

78°

Sullivan, Friday, 9 October, 18:20

Clear. Feels like 77°. High 81°, low 52°.

Pressure30.03 inHg

Wind6.6 mph S

Humidity44%

Visibility6.2 mi

Dew point51°

See detailed hourly forecast

Monthly outlook for Sullivan, IL: average high 72.5°, average low 51.4°. That is 4.4° above the climate normal for October. Precipitation is expected on 2 days (about 0.6 inches), against a normal of 4 days and 1.7 inches. The warmest day looks like 13 October (87.4°), the coolest 18 October (33.7°).

72.5°/51.4°

Average high / low

+4.4°

Above normal

2 / 4

Wet days / normal

0.6 in

Precipitation this month

Ten-day blocks vs climate normal

Period	Forecast high	Normal	Difference
9 October – 18 October	73.9°	65.8°	+4.5°
19 October – 28 October	70.3°	61.4°	+4.9°
29 October – 7 November	at normal	57.6°	—

October records over 66 years

88.7°7 October 2007All-time high

22.5°26 October 1962All-time low

Climate normals and records are computed from the nearest reference point — Lake City (12 mi).

Sat, 1078° / 55°

78 °

Sullivan, Saturday, 10 October

Overcast. High 78°, low 55°.

Pressure30.09 inHg

Wind6.6 mph SE

Humidity48%

Visibility6.2 mi

Dew point53°

Sun, 1180° / 53°

80 °

Sullivan, Sunday, 11 October

Clear. High 80°, low 53°.

Pressure29.94 inHg

Wind6.1 mph NW

Humidity55%

Visibility6.2 mi

Dew point57°

Mon, 1287° / 63°

87 °

Sullivan, Monday, 12 October

Mostly clear. High 87°, low 63°.

Pressure29.91 inHg

Wind11.3 mph SW

Humidity44%

Visibility6.2 mi

Dew point58°

Tue, 1387° / 70°

87 °

Sullivan, Tuesday, 13 October

Overcast. High 87°, low 70°.

Pressure29.85 inHg

Wind10.9 mph W

Humidity57%

Visibility6.2 mi

Dew point68°

Wed, 1472° / 64°

0.31

72 °

Sullivan, Wednesday, 14 October

Rain. High 72°, low 64°.

Pressure30.00 inHg

Wind13.7 mph NE

Humidity90%

Visibility—

Dew point67°

Thu, 1585° / 59°

0.31

85 °

Sullivan, Thursday, 15 October

Rain. High 85°, low 59°.

Pressure29.94 inHg

Wind23.3 mph SW

Humidity61%

Visibility—

Dew point60°

Fri, 1671° / 50°

0.01

71 °

Sullivan, Friday, 16 October

Light rain. High 71°, low 50°.

Pressure30.09 inHg

Wind23.4 mph W

Humidity36%

Visibility—

Dew point32°

Sat, 1746° / 39°

46 °

Sullivan, Saturday, 17 October

Overcast. High 46°, low 39°.

Pressure30.36 inHg

Wind20.8 mph W

Humidity48%

Visibility—

Dew point26°

Sun, 1853° / 34°

53 °

Sullivan, Sunday, 18 October

Clear. High 53°, low 34°.

Pressure30.50 inHg

Wind6.7 mph N

Humidity40%

Visibility—

Dew point26°

Mon, 1959° / 39°

59 °

Sullivan, Monday, 19 October

Overcast. High 59°, low 39°.

Pressure30.42 inHg

Wind7.9 mph S

Humidity31%

Visibility—

Dew point24°

Tue, 2065° / 43°

65 °

Sullivan, Tuesday, 20 October

Clear. High 65°, low 43°.

Pressure30.39 inHg

Wind6 mph SE

Humidity27%

Visibility—

Dew point26°

Wed, 2170° / 45°

70 °

Sullivan, Wednesday, 21 October

Clear. High 70°, low 45°.

Pressure30.33 inHg

Wind7.6 mph S

Humidity25%

Visibility—

Dew point28°

Thu, 2274° / 49°

74 °

Sullivan, Thursday, 22 October

Clear. High 74°, low 49°.

Pressure30.12 inHg

Wind10.4 mph W

Humidity30%

Visibility—

Dew point36°

Fri, 2376° / 53°

76 °

Sullivan, Friday, 23 October

Clear. High 76°, low 53°.

Pressure30.03 inHg

Wind7 mph SW

Humidity31%

Visibility—

Dew point39°

Sat, 2478° / 54°

78 °

Sullivan, Saturday, 24 October

Mostly clear. High 78°, low 54°.

Pressure30.06 inHg

Wind13.1 mph SW

Humidity23%

Visibility—

Dew point33°

From day 17 onward the outlook is built from 60-year climate statistics

Sun, 2561° / 45°

0.13

61 °

Sullivan, Sunday, 25 October

Climate normal for this date — 60-year average.

Average high61°

Average low45°

Average precipitation0.13 in

Chance of precipitation27%

Record high80° (1963)

Record low29° (2013)

Mon, 2660° / 44°

0.13

60 °

Sullivan, Monday, 26 October

Climate normal for this date — 60-year average.

Average high60°

Average low44°

Average precipitation0.13 in

Chance of precipitation30%

Record high82° (1963)

Record low22° (1962)

Tue, 2760° / 44°

0.09

60 °

Sullivan, Tuesday, 27 October

Climate normal for this date — 60-year average.

Average high60°

Average low44°

Average precipitation0.09 in

Chance of precipitation33%

Record high76° (2023)

Record low32° (2001)

Wed, 2859° / 43°

0.06

59 °

Sullivan, Wednesday, 28 October

Climate normal for this date — 60-year average.

Average high59°

Average low43°

Average precipitation0.06 in

Chance of precipitation18%

Record high77° (1999)

Record low27° (1976)

Thu, 2959° / 43°

0.07

59 °

Sullivan, Thursday, 29 October

Climate normal for this date — 60-year average.

Average high59°

Average low43°

Average precipitation0.07 in

Chance of precipitation22%

Record high79° (2004)

Record low25° (1980)

Fri, 3061° / 45°

0.11

61 °

Sullivan, Friday, 30 October

Climate normal for this date — 60-year average.

Average high61°

Average low45°

Average precipitation0.11 in

Chance of precipitation32%

Record high80° (1971)

Record low25° (1980)

Sat, 3160° / 45°

0.17

60 °

Sullivan, Saturday, 31 October

Climate normal for this date — 60-year average.

Average high60°

Average low45°

Average precipitation0.17 in

Chance of precipitation40%

Record high76° (1974)

Record low27° (2023)

Sun, 0159° / 44°

0.2

59 °

Sullivan, Sunday, 1 November

Climate normal for this date — 60-year average.

Average high59°

Average low44°

Average precipitation0.2 in

Chance of precipitation32%

Record high77° (2016)

Record low26° (1993)

Mon, 0258° / 42°

0.09

58 °

Sullivan, Monday, 2 November

Climate normal for this date — 60-year average.

Average high58°

Average low42°

Average precipitation0.09 in

Chance of precipitation30%

Record high77° (2016)

Record low26° (2020)

Tue, 0356° / 41°

0.09

56 °

Sullivan, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high56°

Average low41°

Average precipitation0.09 in

Chance of precipitation30%

Record high76° (1987)

Record low19° (1991)

Wed, 0456° / 43°

0.1

56 °

Sullivan, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high56°

Average low43°

Average precipitation0.1 in

Chance of precipitation28%

Record high75° (2022)

Record low17° (1991)

Thu, 0556° / 41°

0.11

56 °

Sullivan, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high56°

Average low41°

Average precipitation0.11 in

Chance of precipitation28%

Record high76° (1978)

Record low20° (1991)

Fri, 0655° / 40°

0.08

55 °

Sullivan, Friday, 6 November

Climate normal for this date — 60-year average.

Average high55°

Average low40°

Average precipitation0.08 in

Chance of precipitation28%

Record high73° (2023)

Record low26° (1982)

Sat, 0755° / 40°

0.09

55 °

Sullivan, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high55°

Average low40°

Average precipitation0.09 in

Chance of precipitation23%

Record high71° (1980)

Record low18° (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 Sullivan, 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 Sullivan, 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.