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
89°
Wed, Sep 2
Coldest night
48°
Fri, Sep 11
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
86° 61°
57% precip chance
Sat 5 – Sun 6 Sep
81° 65°
81% precip chance
Sat 12 – Sun 13 Sep
75° 59°
typical range
Sat 19 – Sun 20 Sep
75° 59°
typical range
30 days — Petersburg
14 forecast + 16 climatology
Sat · Today Sunny
86°61°1.3 mm⌄
Wind7 mph SE
Gusts17 mph
UV index7 – High
Precip chance57%
Sunrise06:42
Sunset19:52
Sun · Tomorrow Showers
85°65°2.3 mm⌄
Wind9 mph W
Gusts20 mph
UV index8 – Very high
Precip chance57%
Sunrise06:43
Sunset19:50
Monday 31/8 Mostly cloudy
83°70°14%⌄
Wind9 mph W
Gusts15 mph
UV index8 – Very high
Precip chance14%
Sunrise06:44
Sunset19:49
Tuesday 1/9 Mostly cloudy
85°69°0.8 mm⌄
Wind12 mph W
Gusts17 mph
UV index8 – Very high
Precip chance45%
Sunrise06:45
Sunset19:47
Wednesday 2/9 Sunny
89°71°8%⌄
Wind11 mph W
Gusts18 mph
UV index9 – Very high
Precip chance8%
Sunrise06:46
Sunset19:46
Thursday 3/9 Sunny
87°70°2.5 mm⌄
Wind11 mph W
Gusts20 mph
UV index8 – Very high
Precip chance57%
Sunrise06:47
Sunset19:44
Friday 4/9 Showers
78°68°2.8 mm⌄
Wind9 mph NW
Gusts18 mph
UV index7 – High
Precip chance68%
Sunrise06:48
Sunset19:42
Saturday 5/9 Showers
81°66°4.7 mm⌄
Wind9 mph W
Gusts15 mph
UV index6 – High
Precip chance81%
Sunrise06:49
Sunset19:41
Sunday 6/9 Showers
76°65°2.8 mm⌄
Wind8 mph W
Gusts14 mph
UV index6 – High
Precip chance72%
Sunrise06:49
Sunset19:39
Monday 7/9 Sunny
70°62°22%⌄
Wind5 mph W
Gusts13 mph
UV index6 – High
Precip chance22%
Sunrise06:50
Sunset19:38
Tuesday 8/9 Sunny
81°60°9%⌄
Wind11 mph W
Gusts17 mph
UV index7 – High
Precip chance9%
Sunrise06:51
Sunset19:36
Wednesday 9/9 Mostly cloudy
83°64°11%⌄
Wind8 mph W
Gusts11 mph
UV index7 – High
Precip chance11%
Sunrise06:52
Sunset19:35
Thursday 10/9 Mostly cloudy
72°62°17%⌄
Wind13 mph W
Gusts30 mph
UV index5 – Moderate
Precip chance17%
Sunrise06:53
Sunset19:33
Friday 11/9 Sunny
60°48°10%⌄
Wind13 mph W
Gusts24 mph
UV index5 – Moderate
Precip chance10%
Sunrise06:54
Sunset19:31
Saturday 12/9 Rain (climatological)
75°59°5.1 mm⌄
Day≈69–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 13/9 Partly cloudy (climatological)
74°59°20%⌄
Day≈69–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 14/9 Partly cloudy (climatological)
78°61°20%⌄
Day≈73–83°
Night≈56–67°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 15/9 Rain (climatological)
75°59°3.5 mm⌄
Day≈69–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 16/9 Partly cloudy (climatological)
71°58°20%⌄
Day≈66–77°
Night≈52–63°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 17/9 Partly cloudy (climatological)
70°57°20%⌄
Day≈65–75°
Night≈51–62°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 18/9 Light rain (climatological)
71°58°1.9 mm⌄
Day≈66–77°
Night≈52–63°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 19/9 Partly cloudy (climatological)
75°60°20%⌄
Day≈69–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 20/9 Partly cloudy (climatological)
74°59°20%⌄
Day≈69–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Monday 21/9 Light rain (climatological)
75°60°1.9 mm⌄
Day≈70–80°
Night≈54–65°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Tuesday 22/9 Partly cloudy (climatological)
73°59°20%⌄
Day≈68–79°
Night≈53–64°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Wednesday 23/9 Partly cloudy (climatological)
69°56°20%⌄
Day≈64–75°
Night≈51–62°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Thursday 24/9 Rain (climatological)
66°54°2.7 mm⌄
Day≈61–72°
Night≈49–60°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Friday 25/9 Partly cloudy (climatological)
70°57°20%⌄
Day≈65–76°
Night≈51–62°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Saturday 26/9 Partly cloudy (climatological)
71°57°20%⌄
Day≈66–76°
Night≈52–63°
Precip≈1.5 in / September
(climatological)Typical range for these dates · 1991–2020
Sunday 27/9 Rain (climatological)
78°62°4.3 mm⌄
Day≈73–84°
Night≈56–67°
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 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.