St. Charles · first 14 days — live forecast · rest of month — climate corridor
🗺️ 14-day forecast map
St. Charles & neighbors — hit play
Every city on the map carries real forecast data from the same models as its city page, refreshed several times a day. The icon is the day's overall look; the number is the afternoon high.
Next 14 days at a glance
from the model forecast
Hottest day
93°
Thu, Aug 20
Coldest night
62°
Mon, Aug 24
Days with precip
7 / 14
of 14 forecast days
Nicest day
Mon, Aug 24
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 22 – Sun 23 Aug
85° 67°
94% precip chance
Sat 29 – Sun 30 Aug
90° 68°
59% precip chance
Sat 5 – Sun 6 Sep
83° 63°
typical range
Sat 12 – Sun 13 Sep
84° 64°
typical range
30 days — St. Charles
14 forecast + 16 climatology
Thu · Today Sunny
93°70°1.3 mm⌄
Wind11 mph NW
Gusts21 mph
UV index9 – Very high
Precip chance57%
Sunrise06:26
Sunset19:55
Fri · Tomorrow Showers
83°64°4.9 mm⌄
Wind8 mph N
Gusts18 mph
UV index5 – Moderate
Precip chance75%
Sunrise06:27
Sunset19:54
Saturday 22/8 Showers
75°69°24.8 mm⌄
Wind6 mph E
Gusts15 mph
UV index8 – High
Precip chance94%
Sunrise06:28
Sunset19:52
Sunday 23/8 Fog
85°67°2.5 mm⌄
Wind9 mph NW
Gusts17 mph
UV index8 – High
Precip chance63%
Sunrise06:29
Sunset19:51
Monday 24/8 Sunny
87°62°4%⌄
Wind8 mph SE
Gusts18 mph
UV index8 – High
Precip chance4%
Sunrise06:29
Sunset19:50
Tuesday 25/8 Sunny
86°63°9%⌄
Wind8 mph S
Gusts14 mph
UV index7 – High
Precip chance9%
Sunrise06:30
Sunset19:48
Wednesday 26/8 Mostly cloudy
81°65°1.9 mm⌄
Wind6 mph E
Gusts9 mph
UV index6 – High
Precip chance70%
Sunrise06:31
Sunset19:47
Thursday 27/8 Showers
75°69°10.8 mm⌄
Wind4 mph E
Gusts6 mph
UV index5 – Moderate
Precip chance94%
Sunrise06:32
Sunset19:45
Friday 28/8 Sunny
89°68°3.1 mm⌄
Wind4 mph SE
Gusts9 mph
UV index8 – Very high
Precip chance68%
Sunrise06:33
Sunset19:44
Saturday 29/8 Showers
90°69°0.9 mm⌄
Wind5 mph S
Gusts16 mph
UV index8 – Very high
Precip chance55%
Sunrise06:34
Sunset19:42
Sunday 30/8 Fog
89°68°1.0 mm⌄
Wind9 mph SE
Gusts21 mph
UV index8 – Very high
Precip chance59%
Sunrise06:35
Sunset19:41
Monday 31/8 Mostly cloudy
92°69°0.5 mm⌄
Wind9 mph S
Gusts28 mph
UV index8 – Very high
Precip chance40%
Sunrise06:36
Sunset19:39
Tuesday 1/9 Mostly cloudy
85°73°0.4 mm⌄
Wind11 mph W
Gusts25 mph
UV index6 – High
Precip chance36%
Sunrise06:37
Sunset19:38
Wednesday 2/9 Partly cloudy
84°69°0.2 mm⌄
Wind6 mph N
Gusts19 mph
UV index7 – High
Precip chance22%
Sunrise06:37
Sunset19:36
Thursday 3/9 Rain (climatological)
76°60°7.2 mm⌄
Day≈71–82°
Night≈55–66°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 4/9 Partly cloudy (climatological)
84°65°20%⌄
Day≈79–90°
Night≈60–71°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 5/9 Partly cloudy (climatological)
83°65°20%⌄
Day≈78–89°
Night≈59–70°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 6/9 Rain (climatological)
81°63°13.9 mm⌄
Day≈76–87°
Night≈58–69°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 7/9 Partly cloudy (climatological)
76°60°20%⌄
Day≈71–81°
Night≈55–65°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 8/9 Partly cloudy (climatological)
76°60°20%⌄
Day≈71–81°
Night≈55–65°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 9/9 Rain (climatological)
76°60°12.4 mm⌄
Day≈70–81°
Night≈55–65°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 10/9 Partly cloudy (climatological)
80°62°20%⌄
Day≈74–85°
Night≈57–68°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 11/9 Partly cloudy (climatological)
85°65°20%⌄
Day≈79–90°
Night≈60–71°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 12/9 Rain (climatological)
84°65°7.9 mm⌄
Day≈79–90°
Night≈60–71°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 13/9 Partly cloudy (climatological)
82°64°20%⌄
Day≈76–87°
Night≈58–69°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 14/9 Partly cloudy (climatological)
75°60°20%⌄
Day≈70–81°
Night≈54–65°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 15/9 Rain (climatological)
72°58°10.2 mm⌄
Day≈67–78°
Night≈52–63°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Partly cloudy (climatological)
75°60°20%⌄
Day≈70–80°
Night≈54–65°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Partly cloudy (climatological)
79°62°20%⌄
Day≈74–85°
Night≈57–67°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Rain (climatological)
82°64°14.7 mm⌄
Day≈77–88°
Night≈58–69°
Precip≈4.5 in / September
(climatological)Typical range for these dates · 1991–2020
How does a 30-day outlook work?
The first 14 days are a live model forecast. The back half of the month shows the typical range for those dates — useful for planning, not a literal prediction.
First 14 days: a real forecast, blended from NBM, ECMWF and GFS runs. Trust it most inside three days; by the second week treat it as a lean, not a promise.
Rest of the month: past day 14 we stop pretending to forecast and switch to the climate corridor — the range those dates have produced over three decades computed directly for St. Charles, with mild week-to-week wiggle.
Good question for this page: "Is late August usually humid in Chicago?" Bad question: "Do I need an umbrella on the 29th?" — three weeks out no one knows, and that's the honest answer.