Arnold, PA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Arnold, a city in Allegheny County, Pennsylvania.
Today
88°F
Patchy Fog then Sunny
Patchy fog before 9am. Sunny, with a high near 88. East wind around 5 mph.
7-day forecast for Arnold
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 88°F | Patchy Fog then Sunny | 5 mph E | 0% |
| Tonight | 66°F | Mostly Clear | 3 mph E | 1% |
| Wednesday | 89°F | Partly Sunny then Scattered Showers And Thunderstorms | 1 to 6 mph SE | 29% |
| Wednesday Night | 68°F | Scattered Showers And Thunderstorms | 5 mph SE | 50% |
| Thursday | 88°F | Showers And Thunderstorms Likely | 2 to 7 mph SW | 72% |
| Thursday Night | 68°F | Showers And Thunderstorms Likely | 2 to 6 mph SW | 72% |
| Friday | 86°F | Showers And Thunderstorms | 3 to 8 mph SW | 81% |
| Friday Night | 67°F | Showers And Thunderstorms | 1 to 7 mph SW | 81% |
| Saturday | 86°F | Showers And Thunderstorms Likely | 5 to 8 mph SW | 57% |
| Saturday Night | 67°F | Showers And Thunderstorms Likely | 2 to 7 mph SW | 57% |
| Sunday | 88°F | Slight Chance Showers And Thunderstorms | 3 to 10 mph SW | 24% |
| Sunday Night | 70°F | Slight Chance Showers And Thunderstorms | 5 to 9 mph SW | 24% |
| Monday | 89°F | Chance Showers And Thunderstorms | 8 to 12 mph SW | 41% |
| Monday Night | 68°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 49% |
Forecast source: National Weather Service (api.weather.gov) for Arnold (40.579, -79.765). Updated through the day.
Growing snapshot for Arnold
Last spring frost
Apr 16
First fall frost
Nov 2
Growing season
199 days
Hardiness zone
6b
More local growing data for Arnold: nearby ZIP 15030 weather · frost dates · planting calendar · Pennsylvania frost dates
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Climate data from the nearest NOAA station, Natrona Lock 4, Pa (3.7 mi from Arnold). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.