National Weather Service Forecast for: Johnston IA
Issued by: National Weather Service Des Moines, IA
Updated: 6:56 am CDT May 26, 2026
 
Today

Today: Sunny, with a high near 87. South wind 6 to 8 mph.
Sunny
 Tonight

Tonight: Partly cloudy, with a low around 59. South wind around 6 mph becoming calm in the evening.
Partly Cloudy
 Wednesday

Wednesday: Sunny, with a high near 88. Calm wind becoming east around 6 mph in the afternoon.
Sunny
 Wednesday
Night
Wednesday Night: Partly cloudy, with a low around 63. East wind around 6 mph becoming calm in the evening.
Partly Cloudy
 Thursday

Thursday: Mostly sunny, with a high near 84. East wind 7 to 10 mph.
Mostly Sunny
 Thursday
Night
Thursday Night: Mostly cloudy, with a low around 59.
Mostly Cloudy
 Friday

Friday: Partly sunny, with a high near 82.
Partly Sunny
 Friday
Night
Friday Night: Mostly cloudy, with a low around 58.
Mostly Cloudy
 Saturday

Saturday: Mostly sunny, with a high near 81.
Mostly Sunny
Hi 87 °F Lo 59 °F Hi 88 °F Lo 63 °F Hi 84 °F Lo 59 °F Hi 82 °F Lo 58 °F Hi 81 °F

Hazardous Weather Outlook
 

Today
 
 Sunny, with a high near 87. South wind 6 to 8 mph.
Tonight
 
 Partly cloudy, with a low around 59. South wind around 6 mph becoming calm in the evening.
Wednesday
 
 Sunny, with a high near 88. Calm wind becoming east around 6 mph in the afternoon.
Wednesday Night
 
 Partly cloudy, with a low around 63. East wind around 6 mph becoming calm in the evening.
Thursday
 
 Mostly sunny, with a high near 84. East wind 7 to 10 mph.
Thursday Night
 
 Mostly cloudy, with a low around 59.
Friday
 
 Partly sunny, with a high near 82.
Friday Night
 
 Mostly cloudy, with a low around 58.
Saturday
 
 Mostly sunny, with a high near 81.
Saturday Night
 
 Partly cloudy, with a low around 57.
Sunday
 
 Mostly sunny, with a high near 81.
Sunday Night
 
 Partly cloudy, with a low around 56.
Monday
 
 Mostly sunny, with a high near 82.

 

Forecast from NOAA-NWS for Johnston IA.