National Weather Service Forecast for: Johnston IA
Issued by: National Weather Service Des Moines, IA
Updated: 3:24 am CST Feb 2, 2026
 
Overnight

Overnight: Mostly cloudy, with a steady temperature around 27. Calm wind.
Mostly Cloudy

 Monday

Monday: Partly sunny, with a high near 33. Light north northwest wind.
Partly Sunny

 Monday
Night
Monday Night: A slight chance of snow between 2am and 4am. Mostly cloudy, with a low around 18. Light east northeast wind. Chance of precipitation is 20%.
Cloudy then
Slight Chance
Snow
 Tuesday

Tuesday: Mostly sunny, with a high near 29. North wind 3 to 6 mph.
Mostly Sunny

 Tuesday
Night
Tuesday Night: Partly cloudy, with a low around 14. Calm wind.
Partly Cloudy

 Wednesday

Wednesday: Partly sunny, with a high near 33.
Partly Sunny

 Wednesday
Night
Wednesday Night: Mostly cloudy, with a low around 20.
Mostly Cloudy

 Thursday

Thursday: Mostly sunny, with a high near 46.
Mostly Sunny

 Thursday
Night
Thursday Night: Mostly clear, with a low around 33.
Mostly Clear
Lo 27 °F Hi 33 °F Lo 18 °F Hi 29 °F Lo 14 °F Hi 33 °F Lo 20 °F Hi 46 °F Lo 33 °F

 

Overnight
 
 Mostly cloudy, with a steady temperature around 27. Calm wind.
Monday
 
 Partly sunny, with a high near 33. Light north northwest wind.
Monday Night
 
 A slight chance of snow between 2am and 4am. Mostly cloudy, with a low around 18. Light east northeast wind. Chance of precipitation is 20%.
Tuesday
 
 Mostly sunny, with a high near 29. North wind 3 to 6 mph.
Tuesday Night
 
 Partly cloudy, with a low around 14. Calm wind.
Wednesday
 
 Partly sunny, with a high near 33.
Wednesday Night
 
 Mostly cloudy, with a low around 20.
Thursday
 
 Mostly sunny, with a high near 46.
Thursday Night
 
 Mostly clear, with a low around 33.
Friday
 
 Mostly sunny, with a high near 41.
Friday Night
 
 Mostly clear, with a low around 17.
Saturday
 
 Mostly sunny, with a high near 36.
Saturday Night
 
 Partly cloudy, with a low around 22.
Sunday
 
 Mostly sunny, with a high near 42.

 

Forecast from NOAA-NWS for Johnston IA.