Decatur · first 14 days — live forecast · rest of month — climate corridor
🗺️ 14-day forecast map
Decatur & 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
36°
Tue, Aug 25
Coldest night
17°
Mon, Sep 7
Days with precip
6 / 14
of 14 forecast days
Nicest day
Mon, Sep 7
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 29 – Sun 30 Aug
31° 20°
62% precip chance
Sat 5 – Sun 6 Sep
33° 19°
57% precip chance
Sat 12 – Sun 13 Sep
28° 18°
typical range
Sat 19 – Sun 20 Sep
28° 18°
typical range
30 days — Decatur
14 forecast + 16 climatology
Tue · Today Sunny
36°19°1%⌄
Wind6 mph NE
Gusts14 mph
UV index9 – Very high
Precip chance1%
Sunrise07:06
Sunset20:12
Wed · Tomorrow Sunny
34°22°4.4 mm⌄
Wind15 mph W
Gusts19 mph
UV index9 – Very high
Precip chance57%
Sunrise07:06
Sunset20:11
Thursday 27/8 Showers
30°21°4.5 mm⌄
Wind10 mph SW
Gusts12 mph
UV index9 – Very high
Precip chance71%
Sunrise07:07
Sunset20:09
Friday 28/8 Mostly cloudy
33°23°1.3 mm⌄
Wind6 mph SE
Gusts9 mph
UV index7 – High
Precip chance57%
Sunrise07:08
Sunset20:08
Saturday 29/8 Showers
29°20°1.3 mm⌄
Wind7 mph S
Gusts15 mph
UV index7 – High
Precip chance62%
Sunrise07:09
Sunset20:07
Sunday 30/8 Mostly cloudy
31°20°19%⌄
Wind6 mph SE
Gusts15 mph
UV index7 – High
Precip chance19%
Sunrise07:09
Sunset20:05
Monday 31/8 Sunny
36°27°3%⌄
Wind5 mph W
Gusts10 mph
UV index8 – Very high
Precip chance3%
Sunrise07:10
Sunset20:04
Tuesday 1/9 Sunny
35°26°2%⌄
Wind11 mph W
Gusts19 mph
UV index9 – Very high
Precip chance2%
Sunrise07:11
Sunset20:03
Wednesday 2/9 Sunny
35°25°0.8 mm⌄
Wind15 mph W
Gusts23 mph
UV index8 – Very high
Precip chance36%
Sunrise07:11
Sunset20:01
Thursday 3/9 Sunny
31°21°4%⌄
Wind13 mph NW
Gusts21 mph
UV index8 – Very high
Precip chance4%
Sunrise07:12
Sunset20:00
Friday 4/9 Mostly cloudy
30°23°2.4 mm⌄
Wind10 mph W
Gusts24 mph
UV index7 – High
Precip chance58%
Sunrise07:13
Sunset19:59
Saturday 5/9 Sunny
33°21°3.2 mm⌄
Wind13 mph NW
Gusts22 mph
UV index8 – Very high
Precip chance57%
Sunrise07:13
Sunset19:57
Sunday 6/9 Sunny
30°19°1%⌄
Wind8 mph N
Gusts15 mph
UV index7 – High
Precip chance1%
Sunrise07:14
Sunset19:56
Monday 7/9 Mostly cloudy
25°17°6%⌄
Wind8 mph E
Gusts23 mph
UV index6 – High
Precip chance6%
Sunrise07:15
Sunset19:55
Tuesday 8/9 Rain (climatological)
28°19°3.3 mm⌄
Day≈25–31°
Night≈16–22°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 9/9 Partly cloudy (climatological)
31°21°20%⌄
Day≈28–34°
Night≈18–24°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 10/9 Partly cloudy (climatological)
32°21°20%⌄
Day≈29–35°
Night≈18–24°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 11/9 Rain (climatological)
29°20°2.5 mm⌄
Day≈26–32°
Night≈17–23°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 12/9 Partly cloudy (climatological)
27°18°20%⌄
Day≈24–30°
Night≈15–21°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 13/9 Partly cloudy (climatological)
28°19°20%⌄
Day≈25–31°
Night≈16–22°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 14/9 Rain (climatological)
27°18°4.6 mm⌄
Day≈24–30°
Night≈15–21°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 15/9 Partly cloudy (climatological)
30°20°20%⌄
Day≈27–33°
Night≈17–23°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Partly cloudy (climatological)
33°21°20%⌄
Day≈30–36°
Night≈18–24°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Rain (climatological)
32°21°2.3 mm⌄
Day≈29–35°
Night≈18–24°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Partly cloudy (climatological)
31°20°20%⌄
Day≈28–34°
Night≈17–23°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Partly cloudy (climatological)
27°18°20%⌄
Day≈24–30°
Night≈15–21°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Rain (climatological)
28°19°4.0 mm⌄
Day≈25–31°
Night≈16–22°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Partly cloudy (climatological)
29°19°20%⌄
Day≈26–32°
Night≈16–22°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Partly cloudy (climatological)
29°19°20%⌄
Day≈26–32°
Night≈16–22°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Rain (climatological)
31°20°2.2 mm⌄
Day≈28–34°
Night≈17–23°
Precip≈1.5 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 Decatur, 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.