National Weather Service Forecast for: Longmont CO
Issued by: National Weather Service Denver-Boulder, CO
Updated: 12:46 am MDT Jun 22, 2026
 
Overnight

Overnight: Mostly clear, with a low around 56. Calm wind.
Mostly Clear

 Monday

Monday: A 30 percent chance of showers and thunderstorms, mainly between 2pm and 5pm. Mostly sunny, with a high near 90. Calm wind becoming east southeast around 6 mph in the afternoon.
Mostly Sunny
then Chance
T-storms
 Monday
Night
Monday Night: A 20 percent chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 58. East wind 5 to 7 mph becoming light and variable.
Slight Chance
T-storms then
Mostly Clear
 Tuesday

Tuesday: A slight chance of showers and thunderstorms between 4pm and 5pm. Sunny, with a high near 86. North wind 5 to 11 mph becoming east northeast in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 20%.
Sunny then
Slight Chance
T-storms
 Tuesday
Night
Tuesday Night: A 40 percent chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 57. East northeast wind 5 to 10 mph becoming light east in the evening. Winds could gust as high as 18 mph.
Chance
T-storms then
Partly Cloudy
 Wednesday

Wednesday: A 40 percent chance of showers and thunderstorms after noon. Partly sunny, with a high near 85.
Mostly Sunny
then Chance
T-storms
 Wednesday
Night
Wednesday Night: Showers likely and possibly a thunderstorm before midnight, then a slight chance of showers. Mostly cloudy, with a low around 57. Chance of precipitation is 70%.
Showers
Likely then
Slight Chance
Showers
 Thursday

Thursday: Showers likely and possibly a thunderstorm after noon. Mostly cloudy, with a high near 83.
Mostly Cloudy
then Showers
Likely
 Thursday
Night
Thursday Night: A chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 57.
Chance
T-storms then
Mostly Cloudy
Lo 56 °F Hi 90 °F Lo 58 °F Hi 86 °F Lo 57 °F Hi 85 °F Lo 57 °F Hi 83 °F Lo 57 °F

 

Overnight
 
 Mostly clear, with a low around 56. Calm wind.
Monday
 
 A 30 percent chance of showers and thunderstorms, mainly between 2pm and 5pm. Mostly sunny, with a high near 90. Calm wind becoming east southeast around 6 mph in the afternoon.
Monday Night
 
 A 20 percent chance of showers and thunderstorms before 7pm. Mostly clear, with a low around 58. East wind 5 to 7 mph becoming light and variable.
Tuesday
 
 A slight chance of showers and thunderstorms between 4pm and 5pm. Sunny, with a high near 86. North wind 5 to 11 mph becoming east northeast in the afternoon. Winds could gust as high as 21 mph. Chance of precipitation is 20%.
Tuesday Night
 
 A 40 percent chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 57. East northeast wind 5 to 10 mph becoming light east in the evening. Winds could gust as high as 18 mph.
Wednesday
 
 A 40 percent chance of showers and thunderstorms after noon. Partly sunny, with a high near 85.
Wednesday Night
 
 Showers likely and possibly a thunderstorm before midnight, then a slight chance of showers. Mostly cloudy, with a low around 57. Chance of precipitation is 70%.
Thursday
 
 Showers likely and possibly a thunderstorm after noon. Mostly cloudy, with a high near 83.
Thursday Night
 
 A chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 57.
Friday
 
 A slight chance of showers and thunderstorms after noon. Mostly sunny, with a high near 92.
Friday Night
 
 Partly cloudy, with a low around 59.
Saturday
 
 Sunny and hot, with a high near 98. Breezy.
Saturday Night
 
 Mostly clear, with a low around 60. Breezy.
Sunday
 
 Sunny, with a high near 93. Breezy.

 

Forecast from NOAA-NWS for Longmont CO.