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Irwin, PA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Irwin, a borough in Westmoreland County, Pennsylvania.

Today
78°F
Partly Sunny
Partly sunny, with a high near 78. Southeast wind around 5 mph.

7-day forecast for Irwin

WhenTempForecastWindPrecip
Today 78°F Partly Sunny 5 mph SE 3%
Tonight 64°F Chance Rain Showers 8 mph SE 45%
Sunday 77°F Showers And Thunderstorms 8 to 12 mph SW 97%
Sunday Night 55°F Showers And Thunderstorms 12 mph N 92%
Monday 68°F Chance Rain Showers 13 mph NE 40%
Monday Night 53°F Showers And Thunderstorms Likely 14 mph E 68%
Tuesday 63°F Showers And Thunderstorms Likely 14 to 18 mph E 68%
Tuesday Night 50°F Rain Showers Likely 15 to 18 mph E 62%
Wednesday 61°F Rain Showers Likely 17 mph E 62%
Wednesday Night 50°F Showers And Thunderstorms Likely 10 to 16 mph E 56%
Thursday 66°F Chance Rain Showers 13 mph E 54%
Thursday Night 49°F Chance Showers And Thunderstorms 6 to 13 mph NE 30%
Friday 68°F Partly Sunny then Slight Chance Rain Showers 6 to 10 mph NE 19%
Friday Night 49°F Slight Chance Rain Showers then Partly Cloudy 6 to 10 mph NE 19%

Forecast source: National Weather Service (api.weather.gov) for Irwin (40.325, -79.700). Updated through the day.

Growing snapshot for Irwin

Last spring frost
Apr 22
First fall frost
Oct 25
Growing season
186 days
Hardiness zone
6b

More local growing data for Irwin: nearby ZIP 15692 weather · frost dates · planting calendar · Pennsylvania frost dates

Nearby towns & communities

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Climate data from the nearest NOAA station, Murrysville 2 Sw, Pa (6.1 mi from Irwin). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.