National Weather Service Forecast for: Mount Lebanon PA
Issued by: National Weather Service Pittsburgh, PA
Updated: 2:21 am EDT Aug 20, 2026
 
Overnight

Overnight: A chance of showers, then showers likely and possibly a thunderstorm after 5am.  Mostly cloudy, with a low around 65. Calm wind.  Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Showers
Likely

Thursday

Thursday: Showers and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms, mainly between 1pm and 5pm.  High near 75. Calm wind becoming north around 5 mph in the afternoon.  Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Showers then
Showers
Likely
Thursday
Night
Thursday Night: Partly cloudy, with a low around 62. Northeast wind around 6 mph.
Partly Cloudy

Friday

Friday: A chance of showers and thunderstorms, mainly after 3pm.  Mostly sunny, with a high near 79. East wind around 6 mph.  Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Mostly Sunny
then Chance
T-storms
Friday
Night
Friday Night: A slight chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 2am.  Patchy fog after 3am.  Otherwise, partly cloudy, with a low around 64. East wind around 5 mph becoming calm  in the evening.  Chance of precipitation is 20%.
Slight Chance
T-storms and
Patchy Fog
Saturday

Saturday: A chance of showers and thunderstorms after 2pm.  Patchy fog before 7am.  Otherwise, partly sunny, with a high near 80. Chance of precipitation is 40%.
Patchy Fog
then Chance
T-storms
Saturday
Night
Saturday Night: A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am.  Mostly cloudy, with a low around 62. Chance of precipitation is 40%.
Chance
T-storms then
Chance
Showers
Sunday

Sunday: A chance of showers after 2pm.  Partly sunny, with a high near 75. Chance of precipitation is 30%.
Partly Sunny
then Chance
Showers
Sunday
Night
Sunday Night: A chance of showers before 8pm.  Partly cloudy, with a low around 58. Chance of precipitation is 30%.
Chance
Showers then
Partly Cloudy
Lo 65 °F Hi 75 °F Lo 62 °F Hi 79 °F Lo 64 °F Hi 80 °F Lo 62 °F Hi 75 °F Lo 58 °F

Hazardous Weather Outlook
 

Overnight
 
A chance of showers, then showers likely and possibly a thunderstorm after 5am. Mostly cloudy, with a low around 65. Calm wind. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday
 
Showers and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms, mainly between 1pm and 5pm. High near 75. Calm wind becoming north around 5 mph in the afternoon. Chance of precipitation is 90%. New rainfall amounts between three quarters and one inch possible.
Thursday Night
 
Partly cloudy, with a low around 62. Northeast wind around 6 mph.
Friday
 
A chance of showers and thunderstorms, mainly after 3pm. Mostly sunny, with a high near 79. East wind around 6 mph. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday Night
 
A slight chance of showers and thunderstorms before 8pm, then a slight chance of showers between 8pm and 2am. Patchy fog after 3am. Otherwise, partly cloudy, with a low around 64. East wind around 5 mph becoming calm in the evening. Chance of precipitation is 20%.
Saturday
 
A chance of showers and thunderstorms after 2pm. Patchy fog before 7am. Otherwise, partly sunny, with a high near 80. Chance of precipitation is 40%.
Saturday Night
 
A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 62. Chance of precipitation is 40%.
Sunday
 
A chance of showers after 2pm. Partly sunny, with a high near 75. Chance of precipitation is 30%.
Sunday Night
 
A chance of showers before 8pm. Partly cloudy, with a low around 58. Chance of precipitation is 30%.
Monday
 
Sunny, with a high near 75.
Monday Night
 
Mostly clear, with a low around 58.
Tuesday
 
Mostly sunny, with a high near 78.
Tuesday Night
 
Partly cloudy, with a low around 60.
Wednesday
 
Mostly sunny, with a high near 80.

 

Forecast from NOAA-NWS for Mount Lebanon PA.