Petersburg · first 14 days — live forecast · rest of month — climate corridor
🗺️ 14-day forecast map
Petersburg & 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
104°
Fri, Sep 4
Coldest night
59°
Sat, Sep 12
Days with precip
3 / 14
of 14 forecast days
Nicest day
Sat, Sep 12
mild, dry, light wind
The next 4 weekends
plan ahead
Sat 5 – Sun 6 Sep
94° 73°
85% precip chance
Sat 12 – Sun 13 Sep
87° 59°
typical range
Sat 19 – Sun 20 Sep
88° 64°
typical range
Sat 26 – Sun 27 Sep
87° 63°
typical range
30 days — Petersburg
14 forecast + 16 climatology
Sun · Today Sunny
93°67°12%⌄
Wind8 mph S
Gusts22 mph
UV index8 – Very high
Precip chance12%
Sunrise06:38
Sunset19:41
Mon · Tomorrow Sunny
100°72°5%⌄
Wind8 mph E
Gusts21 mph
UV index9 – Very high
Precip chance5%
Sunrise06:39
Sunset19:40
Tuesday 1/9 Mostly cloudy
98°74°11%⌄
Wind6 mph N
Gusts18 mph
UV index9 – Very high
Precip chance11%
Sunrise06:40
Sunset19:38
Wednesday 2/9 Sunny
104°76°4%⌄
Wind7 mph E
Gusts13 mph
UV index9 – Very high
Precip chance4%
Sunrise06:41
Sunset19:37
Thursday 3/9 Sunny
103°76°17%⌄
Wind5 mph SW
Gusts14 mph
UV index9 – Very high
Precip chance17%
Sunrise06:41
Sunset19:35
Friday 4/9 Sunny
104°74°1.1 mm⌄
Wind16 mph N
Gusts34 mph
UV index10 – Very high
Precip chance57%
Sunrise06:42
Sunset19:34
Saturday 5/9 Sunny
94°73°0.8 mm⌄
Wind11 mph NW
Gusts25 mph
UV index8 – Very high
Precip chance38%
Sunrise06:43
Sunset19:33
Sunday 6/9 Showers
88°73°13.3 mm⌄
Wind11 mph W
Gusts29 mph
UV index7 – High
Precip chance85%
Sunrise06:44
Sunset19:31
Monday 7/9 Sunny
89°69°1.4 mm⌄
Wind11 mph NW
Gusts28 mph
UV index8 – Very high
Precip chance57%
Sunrise06:45
Sunset19:30
Tuesday 8/9 Mostly cloudy
88°64°13%⌄
Wind10 mph W
Gusts17 mph
UV index7 – High
Precip chance13%
Sunrise06:46
Sunset19:28
Wednesday 9/9 Sunny
89°71°9%⌄
Wind9 mph NW
Gusts20 mph
UV index8 – Very high
Precip chance9%
Sunrise06:46
Sunset19:27
Thursday 10/9 Mostly cloudy
95°71°9%⌄
Wind13 mph N
Gusts26 mph
UV index8 – Very high
Precip chance9%
Sunrise06:47
Sunset19:25
Friday 11/9 Sunny
80°64°2%⌄
Wind10 mph N
Gusts20 mph
UV index7 – High
Precip chance2%
Sunrise06:48
Sunset19:23
Saturday 12/9 Sunny
79°59°4%⌄
Wind9 mph N
Gusts19 mph
UV index7 – High
Precip chance4%
Sunrise06:49
Sunset19:22
Sunday 13/9 Light rain (climatological)
87°65°1.9 mm⌄
Day≈82–93°
Night≈60–70°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 14/9 Partly cloudy (climatological)
92°68°20%⌄
Day≈87–97°
Night≈62–73°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 15/9 Partly cloudy (climatological)
91°67°20%⌄
Day≈85–96°
Night≈62–73°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Rain (climatological)
88°65°4.8 mm⌄
Day≈83–93°
Night≈60–71°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Partly cloudy (climatological)
87°65°20%⌄
Day≈81–92°
Night≈59–70°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Partly cloudy (climatological)
82°62°20%⌄
Day≈77–88°
Night≈56–67°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Light rain (climatological)
85°64°2.0 mm⌄
Day≈80–90°
Night≈58–69°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Partly cloudy (climatological)
88°65°20%⌄
Day≈82–93°
Night≈60–71°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Partly cloudy (climatological)
92°67°20%⌄
Day≈86–97°
Night≈62–73°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Rain (climatological)
90°67°2.4 mm⌄
Day≈85–95°
Night≈61–72°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Partly cloudy (climatological)
90°67°20%⌄
Day≈85–95°
Night≈61–72°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Partly cloudy (climatological)
87°64°20%⌄
Day≈81–92°
Night≈59–70°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Rain (climatological)
82°62°3.8 mm⌄
Day≈77–88°
Night≈56–67°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Partly cloudy (climatological)
84°63°20%⌄
Day≈78–89°
Night≈57–68°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Partly cloudy (climatological)
87°65°20%⌄
Day≈82–92°
Night≈59–70°
Precip≈1.4 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 28/9 Rain (climatological)
92°68°2.4 mm⌄
Day≈87–97°
Night≈62–73°
Precip≈1.4 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 Petersburg, 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.