Petersburg, IL Weather Forecast
Local 7-day forecast
Showers And Thunderstorms
Track current conditions, temperature changes, wind, and the full daily outlook for Petersburg, IL in one place.
Showers and thunderstorms. Mostly cloudy, with a high near 75. South wind 8 to 12 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Local Weather Overview
This forecast page for Petersburg, IL is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Oct 15, 2026 1:45 PM CDT.
The active forecast window currently covers Oct 15 to Oct 21, 2026 for Petersburg, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Oct 15 to Oct 21, 2026
- Latest sync
- Oct 15, 2026 1:45 PM CDT
- Forecast office
- ILX
- Source
- NOAA / NWS
Daily Outlook
This Week in Petersburg
Wednesday looks like the warmest upcoming period in Petersburg at 77 degrees F.
Friday Night is the coolest period ahead with temperatures near 35 degrees F.
The strongest winds are forecast for Friday at about 17 to 21 mph NW.
Precipitation is mentioned in 4 upcoming forecast periods.
Forecast Details
- Last updated
- Oct 15, 2026 1:45 PM CDT
- Coverage
- 7 days
- Time zone
- America/Chicago
- Forecast office
- ILX
- Radar station
- KILX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Showers and thunderstorms likely before 1am. Mostly cloudy, with a low around 45. West wind 12 to 17 mph, with gusts as high as 28 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
A chance of rain showers after noon. Partly sunny, with a high near 55. Northwest wind 17 to 21 mph, with gusts as high as 33 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
A slight chance of rain showers before 7pm, then areas of frost. Partly cloudy, with a low around 35. North northwest wind 5 to 17 mph, with gusts as high as 28 mph. New rainfall amounts less than a tenth of an inch possible.
Areas of frost before 8am. Sunny, with a high near 59. North northwest wind 0 to 3 mph.
Areas of frost after 5am. Clear, with a low around 35. South southeast wind 1 to 5 mph.
Areas of frost before 8am. Sunny, with a high near 68. South wind 5 to 8 mph.
Mostly clear, with a low around 39.
Mostly sunny, with a high near 72.
Partly cloudy, with a low around 41.
Mostly sunny, with a high near 75.
Mostly clear, with a low around 44.
Sunny, with a high near 77.
Mostly clear, with a low around 49.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Today
Oct 15
|
Showers And Thunderstorms
|
75°F |
8 to 12 mph
S
|
|
Tonight
Oct 15
|
Showers And Thunderstorms Likely
|
45°F |
12 to 17 mph
W
|
|
Friday
Oct 16
|
Partly Sunny then Chance Rain Showers
|
55°F |
17 to 21 mph
NW
|
|
Friday Night
Oct 16
|
Slight Chance Rain Showers then Areas Of Frost
|
35°F |
5 to 17 mph
NNW
|
|
Saturday
Oct 17
|
Areas Of Frost then Sunny
|
59°F |
0 to 3 mph
NNW
|
|
Saturday Night
Oct 17
|
Clear then Areas Of Frost
|
35°F |
1 to 5 mph
SSE
|
|
Sunday
Oct 18
|
Areas Of Frost then Sunny
|
68°F |
5 to 8 mph
S
|
|
Sunday Night
Oct 18
|
Mostly Clear
|
39°F |
6 mph
S
|
|
Monday
Oct 19
|
Mostly Sunny
|
72°F |
3 mph
S
|
|
Monday Night
Oct 19
|
Partly Cloudy
|
41°F |
2 mph
SSE
|
|
Tuesday
Oct 20
|
Mostly Sunny
|
75°F |
0 to 3 mph
SE
|
|
Tuesday Night
Oct 20
|
Mostly Clear
|
44°F |
2 mph
SE
|
|
Wednesday
Oct 21
|
Sunny
|
77°F |
2 to 6 mph
SSE
|
|
Wednesday Night
Oct 21
|
Mostly Clear
|
49°F |
5 mph
SSE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Petersburg.