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
40°
Fri, Sep 11
Coldest night
18°
Wed, Sep 16
Days with precip
2 / 14
of 14 forecast days
Nicest day
Fri, Sep 4
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 5 – Sun 6 Sep
39° 26°
4% precip chance
Sat 12 – Sun 13 Sep
38° 27°
1% precip chance
Sat 19 – Sun 20 Sep
39° 26°
typical range
Sat 26 – Sun 27 Sep
41° 26°
typical range
30 days — Decatur
14 forecast + 16 climatology
Thu · Today Sunny
39°24°2%⌄
Wind12 mph S
Gusts29 mph
UV index9 – Very high
Precip chance2%
Sunrise06:50
Sunset19:43
Fri · Tomorrow Sunny
37°24°2%⌄
Wind13 mph SE
Gusts24 mph
UV index9 – Very high
Precip chance2%
Sunrise06:51
Sunset19:42
Saturday 5/9 Sunny
37°26°4%⌄
Wind12 mph S
Gusts23 mph
UV index9 – Very high
Precip chance4%
Sunrise06:52
Sunset19:40
Sunday 6/9 Sunny
39°26°3%⌄
Wind13 mph E
Gusts20 mph
UV index9 – Very high
Precip chance3%
Sunrise06:53
Sunset19:39
Monday 7/9 Sunny
39°25°17%⌄
Wind11 mph SE
Gusts31 mph
UV index9 – Very high
Precip chance17%
Sunrise06:54
Sunset19:37
Tuesday 8/9 Sunny
40°25°1%⌄
Wind11 mph SE
Gusts30 mph
UV index9 – Very high
Precip chance1%
Sunrise06:54
Sunset19:36
Wednesday 9/9 Sunny
39°29°1%⌄
Wind12 mph SW
Gusts30 mph
UV index9 – Very high
Precip chance1%
Sunrise06:55
Sunset19:34
Thursday 10/9 Sunny
39°27°1%⌄
Wind13 mph S
Gusts32 mph
UV index9 – Very high
Precip chance1%
Sunrise06:56
Sunset19:33
Friday 11/9 Sunny
40°28°1%⌄
Wind11 mph SW
Gusts28 mph
UV index9 – Very high
Precip chance1%
Sunrise06:57
Sunset19:31
Saturday 12/9 Sunny
38°29°1%⌄
Wind14 mph S
Gusts30 mph
UV index9 – Very high
Precip chance1%
Sunrise06:58
Sunset19:30
Sunday 13/9 Sunny
38°27°1%⌄
Wind15 mph S
Gusts33 mph
UV index9 – Very high
Precip chance1%
Sunrise06:58
Sunset19:28
Monday 14/9 Mostly cloudy
37°27°0.6 mm⌄
Wind16 mph SW
Gusts34 mph
UV index8 – Very high
Precip chance36%
Sunrise06:59
Sunset19:27
Tuesday 15/9 Sunny
34°21°5.1 mm⌄
Wind10 mph NE
Gusts30 mph
UV index8 – Very high
Precip chance57%
Sunrise07:00
Sunset19:25
Wednesday 16/9 Showers
30°18°9.1 mm⌄
Wind11 mph S
Gusts24 mph
UV index7 – High
Precip chance74%
Sunrise07:01
Sunset19:24
Thursday 17/9 Rain (climatological)
37°25°3.1 mm⌄
Day≈34–40°
Night≈22–28°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Partly cloudy (climatological)
41°28°20%⌄
Day≈38–44°
Night≈25–31°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Partly cloudy (climatological)
39°27°20%⌄
Day≈36–42°
Night≈24–30°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Rain (climatological)
38°26°2.3 mm⌄
Day≈35–41°
Night≈23–29°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Partly cloudy (climatological)
36°24°20%⌄
Day≈33–39°
Night≈21–27°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Partly cloudy (climatological)
36°25°20%⌄
Day≈33–39°
Night≈22–28°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Light rain (climatological)
36°25°1.9 mm⌄
Day≈33–39°
Night≈22–28°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Partly cloudy (climatological)
38°26°20%⌄
Day≈35–41°
Night≈23–29°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Partly cloudy (climatological)
39°26°20%⌄
Day≈36–42°
Night≈23–29°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Rain (climatological)
41°27°3.2 mm⌄
Day≈38–44°
Night≈24–30°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Partly cloudy (climatological)
39°26°20%⌄
Day≈36–42°
Night≈23–29°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 28/9 Partly cloudy (climatological)
37°25°20%⌄
Day≈34–40°
Night≈22–28°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 29/9 Rain (climatological)
36°24°2.7 mm⌄
Day≈33–39°
Night≈21–27°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 30/9 Partly cloudy (climatological)
36°24°20%⌄
Day≈33–39°
Night≈21–27°
Precip≈1.3 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 1/10 Partly cloudy (climatological)
33°21°20%⌄
Day≈30–36°
Night≈18–24°
Precip≈1.3 in / October
(climatological)Typical range for these dates · 1991–2020
Friday 2/10 Rain (climatological)
34°21°3.7 mm⌄
Day≈31–37°
Night≈18–24°
Precip≈1.3 in / October
(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.