As of 04:55 CDT

Weather in Chester, IL

53°

Chester, Sunday, 11 October, 04:55

Clear. Feels like 52°. High 85°, low 52°.

Pressure29.97 inHg

Wind3.4 mph W

Humidity88%

Visibility6.2 mi

Dew point49°

See detailed hourly forecast

Monthly outlook for Chester, IL: average high 71.8°, average low 49.5°. That is 2.6° above the climate normal for October. Precipitation is expected on 3 days (about 1.9 inches), against a normal of 4 days and 1.8 inches. The warmest day looks like 13 October (90.9°), the coolest 18 October (28.6°).

71.8°/49.5°

Average high / low

+2.6°

Above normal

3 / 4

Wet days / normal

1.9 in

Precipitation this month

Ten-day blocks vs climate normal

Period	Forecast high	Normal	Difference
11 October – 20 October	72.7°	68.2°	+2.5°
21 October – 30 October	70.4°	64.4°	+3.3°
31 October – 9 November	at normal	60.2°	—

October records over 66 years

93.6°1 October 2019All-time high

26.8°24 October 1981All-time low

Climate normals and records are computed from the nearest reference point — St. Mary (7 mi).

Mon, 1291° / 59°

91 °

Chester, Monday, 12 October

Clear. High 91°, low 59°.

Pressure29.97 inHg

Wind11.3 mph SW

Humidity40%

Visibility6.2 mi

Dew point59°

Tue, 1391° / 67°

91 °

Chester, Tuesday, 13 October

Clear. High 91°, low 67°.

Pressure29.91 inHg

Wind7.7 mph SW

Humidity47%

Visibility6.2 mi

Dew point64°

Wed, 1479° / 72°

0.21

79 °

Chester, Wednesday, 14 October

Rain. High 79°, low 72°.

Pressure30.03 inHg

Wind5.1 mph S

Humidity94%

Visibility6.2 mi

Dew point72°

Thu, 1583° / 71°

0.46

83 °

Chester, Thursday, 15 October

Rain. High 83°, low 71°.

Pressure30.06 inHg

Wind8.5 mph SW

Humidity77%

Visibility—

Dew point71°

Fri, 1671° / 49°

1.26

71 °

Chester, Friday, 16 October

Heavy rain. High 71°, low 49°.

Pressure30.33 inHg

Wind16.6 mph N

Humidity56%

Visibility—

Dew point50°

Sat, 1745° / 34°

45 °

Chester, Saturday, 17 October

Overcast. High 45°, low 34°.

Pressure30.42 inHg

Wind21.5 mph NW

Humidity35%

Visibility—

Dew point17°

Sun, 1852° / 29°

52 °

Chester, Sunday, 18 October

Clear. High 52°, low 29°.

Pressure30.56 inHg

Wind6.9 mph NW

Humidity29%

Visibility—

Dew point17°

Mon, 1962° / 34°

62 °

Chester, Monday, 19 October

Clear. High 62°, low 34°.

Pressure30.39 inHg

Wind12.5 mph S

Humidity25%

Visibility—

Dew point20°

Tue, 2069° / 41°

69 °

Chester, Tuesday, 20 October

Clear. High 69°, low 41°.

Pressure30.27 inHg

Wind12.6 mph S

Humidity19%

Visibility—

Dew point20°

Wed, 2171° / 45°

71 °

Chester, Wednesday, 21 October

Overcast. High 71°, low 45°.

Pressure30.27 inHg

Wind12.5 mph S

Humidity25%

Visibility—

Dew point29°

Thu, 2275° / 52°

75 °

Chester, Thursday, 22 October

Partly cloudy. High 75°, low 52°.

Pressure30.33 inHg

Wind6.7 mph S

Humidity38%

Visibility—

Dew point44°

Fri, 2376° / 53°

76 °

Chester, Friday, 23 October

Clear. High 76°, low 53°.

Pressure30.30 inHg

Wind8 mph S

Humidity46%

Visibility—

Dew point49°

Sat, 2473° / 54°

0.01

73 °

Chester, Saturday, 24 October

Light rain. High 73°, low 54°.

Pressure30.15 inHg

Wind12.9 mph NW

Humidity55%

Visibility—

Dew point54°

Sun, 2559° / 41°

59 °

Chester, Sunday, 25 October

Clear. High 59°, low 41°.

Pressure30.39 inHg

Wind9.9 mph N

Humidity38%

Visibility—

Dew point30°

Mon, 2668° / 40°

68 °

Chester, Monday, 26 October

Clear. High 68°, low 40°.

Pressure30.15 inHg

Wind14.1 mph NW

Humidity31%

Visibility—

Dew point31°

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

Tue, 2763° / 47°

0.14

63 °

Chester, Tuesday, 27 October

Climate normal for this date — 60-year average.

Average high63°

Average low47°

Average precipitation0.14 in

Chance of precipitation27%

Record high81° (2023)

Record low35° (2001)

Wed, 2863° / 46°

0.07

63 °

Chester, Wednesday, 28 October

Climate normal for this date — 60-year average.

Average high63°

Average low46°

Average precipitation0.07 in

Chance of precipitation27%

Record high81° (1999)

Record low30° (1976)

Thu, 2962° / 46°

0.13

62 °

Chester, Thursday, 29 October

Climate normal for this date — 60-year average.

Average high62°

Average low46°

Average precipitation0.13 in

Chance of precipitation28%

Record high81° (1971)

Record low30° (2017)

Fri, 3064° / 48°

0.13

64 °

Chester, Friday, 30 October

Climate normal for this date — 60-year average.

Average high64°

Average low48°

Average precipitation0.13 in

Chance of precipitation28%

Record high80° (1971)

Record low29° (1980)

Sat, 3164° / 48°

0.17

64 °

Chester, Saturday, 31 October

Climate normal for this date — 60-year average.

Average high64°

Average low48°

Average precipitation0.17 in

Chance of precipitation38%

Record high78° (1968)

Record low28° (2023)

Sun, 0163° / 47°

0.16

63 °

Chester, Sunday, 1 November

Climate normal for this date — 60-year average.

Average high63°

Average low47°

Average precipitation0.16 in

Chance of precipitation35%

Record high80° (2016)

Record low26° (1993)

Mon, 0261° / 46°

0.09

61 °

Chester, Monday, 2 November

Climate normal for this date — 60-year average.

Average high61°

Average low46°

Average precipitation0.09 in

Chance of precipitation30%

Record high80° (2016)

Record low29° (1966)

Tue, 0360° / 45°

0.08

60 °

Chester, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high60°

Average low45°

Average precipitation0.08 in

Chance of precipitation30%

Record high78° (1987)

Record low24° (1991)

Wed, 0460° / 45°

0.11

60 °

Chester, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high60°

Average low45°

Average precipitation0.11 in

Chance of precipitation25%

Record high77° (1978)

Record low20° (1991)

Thu, 0559° / 44°

0.15

59 °

Chester, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high59°

Average low44°

Average precipitation0.15 in

Chance of precipitation35%

Record high77° (1978)

Record low24° (1991)

Fri, 0658° / 42°

0.11

58 °

Chester, Friday, 6 November

Climate normal for this date — 60-year average.

Average high58°

Average low42°

Average precipitation0.11 in

Chance of precipitation32%

Record high77° (1999)

Record low27° (1982)

Sat, 0759° / 43°

0.1

59 °

Chester, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high59°

Average low43°

Average precipitation0.1 in

Chance of precipitation20%

Record high77° (1999)

Record low22° (1993)

Sun, 0859° / 43°

0.03

59 °

Chester, Sunday, 8 November

Climate normal for this date — 60-year average.

Average high59°

Average low43°

Average precipitation0.03 in

Chance of precipitation15%

Record high79° (1999)

Record low16° (1991)

Mon, 0960° / 43°

0.07

60 °

Chester, Monday, 9 November

Climate normal for this date — 60-year average.

Average high60°

Average low43°

Average precipitation0.07 in

Chance of precipitation25%

Record high77° (2022)

Record low19° (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 Chester, 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 Chester, 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.