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
44°
Tue, Sep 1
Coldest night
22°
Wed, Aug 26
Days with precip
4 / 14
of 14 forecast days
Nicest day
Thu, Aug 27
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 22 – Sun 23 Aug
39° 24°
17% precip chance
Sat 29 – Sun 30 Aug
42° 24°
57% precip chance
Sat 5 – Sun 6 Sep
41° 24°
typical range
Sat 12 – Sun 13 Sep
40° 24°
typical range
30 days — Decatur
14 forecast + 16 climatology
Fri · Today Sunny
42°23°3%⌄
Wind8 mph SE
Gusts27 mph
UV index9 – Very high
Precip chance3%
Sunrise06:40
Sunset20:01
Sat · Tomorrow Mostly cloudy
38°24°0.2 mm⌄
Wind11 mph E
Gusts28 mph
UV index9 – Very high
Precip chance17%
Sunrise06:41
Sunset19:59
Sunday 23/8 Sunny
39°25°7%⌄
Wind13 mph E
Gusts28 mph
UV index8 – Very high
Precip chance7%
Sunrise06:42
Sunset19:58
Monday 24/8 Mostly cloudy
42°23°1.0 mm⌄
Wind15 mph SE
Gusts38 mph
UV index9 – Very high
Precip chance57%
Sunrise06:43
Sunset19:57
Tuesday 25/8 Showers
39°24°0.7 mm⌄
Wind15 mph SW
Gusts32 mph
UV index8 – Very high
Precip chance36%
Sunrise06:43
Sunset19:56
Wednesday 26/8 Showers
38°22°4.3 mm⌄
Wind9 mph SW
Gusts16 mph
UV index9 – Very high
Precip chance60%
Sunrise06:44
Sunset19:54
Thursday 27/8 Mostly cloudy
40°26°4%⌄
Wind11 mph SW
Gusts23 mph
UV index9 – Very high
Precip chance4%
Sunrise06:45
Sunset19:53
Friday 28/8 Sunny
42°25°17%⌄
Wind15 mph SW
Gusts33 mph
UV index10 – Very high
Precip chance17%
Sunrise06:46
Sunset19:51
Saturday 29/8 Showers
42°30°1.3 mm⌄
Wind17 mph SW
Gusts35 mph
UV index10 – Very high
Precip chance57%
Sunrise06:47
Sunset19:50
Sunday 30/8 Showers
37°24°3.0 mm⌄
Wind8 mph NE
Gusts19 mph
UV index9 – Very high
Precip chance57%
Sunrise06:47
Sunset19:49
Monday 31/8 Sunny
42°28°2%⌄
Wind13 mph SW
Gusts30 mph
UV index10 – Very high
Precip chance2%
Sunrise06:48
Sunset19:47
Tuesday 1/9 Sunny
44°28°2%⌄
Wind17 mph SE
Gusts35 mph
UV index10 – Very high
Precip chance2%
Sunrise06:49
Sunset19:46
Wednesday 2/9 Sunny
41°28°0.5 mm⌄
Wind17 mph SE
Gusts34 mph
UV index10 – Very high
Precip chance36%
Sunrise06:50
Sunset19:44
Thursday 3/9 Sunny
41°25°0.1 mm⌄
Wind11 mph SW
Gusts29 mph
UV index10 – Very high
Precip chance17%
Sunrise06:50
Sunset19:43
Friday 4/9 Rain (climatological)
36°22°2.3 mm⌄
Day≈33–39°
Night≈19–25°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 5/9 Partly cloudy (climatological)
41°25°20%⌄
Day≈38–44°
Night≈22–28°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 6/9 Partly cloudy (climatological)
39°24°20%⌄
Day≈36–42°
Night≈21–27°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 7/9 Light rain (climatological)
38°23°1.8 mm⌄
Day≈35–41°
Night≈20–26°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 8/9 Partly cloudy (climatological)
35°22°20%⌄
Day≈32–38°
Night≈19–25°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 9/9 Partly cloudy (climatological)
36°22°20%⌄
Day≈33–39°
Night≈19–25°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 10/9 Light rain (climatological)
36°22°1.4 mm⌄
Day≈33–39°
Night≈19–25°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 11/9 Partly cloudy (climatological)
38°23°20%⌄
Day≈35–41°
Night≈20–26°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 12/9 Partly cloudy (climatological)
39°24°20%⌄
Day≈36–42°
Night≈21–27°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 13/9 Rain (climatological)
40°25°2.4 mm⌄
Day≈37–43°
Night≈22–28°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 14/9 Partly cloudy (climatological)
39°23°20%⌄
Day≈36–42°
Night≈20–26°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 15/9 Partly cloudy (climatological)
37°23°20%⌄
Day≈34–40°
Night≈20–26°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Light rain (climatological)
35°21°2.0 mm⌄
Day≈32–38°
Night≈18–24°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Partly cloudy (climatological)
35°21°20%⌄
Day≈32–38°
Night≈18–24°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Partly cloudy (climatological)
39°23°20%⌄
Day≈36–42°
Night≈20–26°
Precip≈0.9 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Rain (climatological)
39°24°2.8 mm⌄
Day≈36–42°
Night≈21–27°
Precip≈0.9 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.