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Newcastle, CA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Newcastle, a community in Placer County, California.

Today
102°F
Sunny
Sunny, with a high near 102. South southwest wind around 6 mph.

7-day forecast for Newcastle

WhenTempForecastWindPrecip
Today 102°F Sunny 6 mph SSW 0%
Tonight 68°F Clear 5 mph SSE 0%
Wednesday 100°F Sunny 6 mph SSW 0%
Wednesday Night 67°F Clear 5 mph S 0%
Thursday 100°F Sunny 5 mph SSW 0%
Thursday Night 68°F Clear 5 mph S 0%
Friday 101°F Sunny 5 mph S 0%
Friday Night 70°F Clear 5 mph SSE 0%
Saturday 102°F Sunny 5 mph SSE 0%
Saturday Night 70°F Mostly Clear 6 mph S 0%
Sunday 100°F Sunny 3 to 7 mph SSE 0%
Sunday Night 66°F Mostly Clear 3 to 7 mph SSE 0%
Monday 94°F Sunny 3 to 7 mph S 0%
Monday Night 62°F Mostly Clear 3 to 7 mph S 0%

Forecast source: National Weather Service (api.weather.gov) for Newcastle (38.867, -121.132). Updated through the day.

Growing snapshot for Newcastle

Last spring frost
Feb 25
First fall frost
Dec 5
Growing season
286 days
Hardiness zone
9b

More local growing data for Newcastle: nearby ZIP 95658 weather · frost dates · planting calendar · California frost dates

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Climate data from the nearest NOAA station, Auburn, Ca (4.9 mi from Newcastle). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.