Saint Johns, IL Weather Forecast
Local 7-day forecast
Showers And Thunderstorms Likely
Track current conditions, temperature changes, wind, and the full daily outlook for Saint Johns, IL in one place.
Showers and thunderstorms likely. Mostly cloudy, with a high near 69. West wind 12 to 15 mph, with gusts as high as 23 mph. Chance of precipitation is 60%.
Local Weather Overview
This forecast page for Saint Johns, 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: Apr 15, 2026 11:28 PM CDT.
The active forecast window currently covers Apr 18 to Apr 22, 2026 for Saint Johns, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Apr 18 to Apr 22, 2026
- Latest sync
- Apr 15, 2026 11:28 PM CDT
- Forecast office
- PAH
- Source
- NOAA / NWS
Daily Outlook
This Week in Saint Johns
Wednesday looks like the warmest upcoming period in Saint Johns at 78 degrees F.
Saturday Night is the coolest period ahead with temperatures near 40 degrees F.
The strongest winds are forecast for Saturday at about 12 to 15 mph W.
Precipitation is mentioned in 3 upcoming forecast periods.
Forecast Details
- Last updated
- Apr 15, 2026 11:28 PM CDT
- Coverage
- 5 days
- Time zone
- America/Chicago
- Forecast office
- PAH
- Radar station
- KPAH
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A chance of rain showers before 1am. Partly cloudy, with a low around 40. Northwest wind 6 to 13 mph, with gusts as high as 21 mph.
Sunny, with a high near 65. Northwest wind 6 to 12 mph, with gusts as high as 20 mph.
Clear, with a low around 41. Northeast wind 5 to 8 mph.
Sunny, with a high near 71. South wind 5 to 9 mph.
Mostly clear, with a low around 50. South wind around 7 mph.
Sunny, with a high near 76. South southwest wind 7 to 13 mph, with gusts as high as 21 mph.
Mostly clear, with a low around 55. South southwest wind 7 to 10 mph, with gusts as high as 18 mph.
A slight chance of rain showers between 7am and 1pm, then a slight chance of showers and thunderstorms. Mostly sunny, with a high near 78. South southwest wind 7 to 10 mph, with gusts as high as 18 mph.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Saturday
Apr 18
|
Showers And Thunderstorms Likely
|
69°F |
12 to 15 mph
W
|
|
Saturday Night
Apr 18
|
Chance Rain Showers
|
40°F |
6 to 13 mph
NW
|
|
Sunday
Apr 19
|
Sunny
|
65°F |
6 to 12 mph
NW
|
|
Sunday Night
Apr 19
|
Clear
|
41°F |
5 to 8 mph
NE
|
|
Monday
Apr 20
|
Sunny
|
71°F |
5 to 9 mph
S
|
|
Monday Night
Apr 20
|
Mostly Clear
|
50°F |
7 mph
S
|
|
Tuesday
Apr 21
|
Sunny
|
76°F |
7 to 13 mph
SSW
|
|
Tuesday Night
Apr 21
|
Mostly Clear
|
55°F |
7 to 10 mph
SSW
|
|
Wednesday
Apr 22
|
Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms
|
78°F |
7 to 10 mph
SSW
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Saint Johns.