Diamond Bar, CA Weather & Growing Conditions
This Afternoon
80°F
Sunny
Sunny, with a high near 80. West southwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 80°F | Sunny | 10 mph WSW | 0% |
| Tonight | 59°F | Mostly Clear | 5 to 10 mph SSW | 0% |
| Saturday | 82°F | Sunny | 5 to 10 mph SSW | 0% |
| Saturday Night | 61°F | Patchy Fog | 5 to 10 mph SSW | 0% |
| Sunday | 82°F | Patchy Fog then Mostly Cloudy | 5 to 10 mph SW | 0% |
| Sunday Night | 61°F | Mostly Cloudy | 5 mph SSW | 1% |
| Monday | 79°F | Mostly Sunny | 5 to 10 mph SSW | 1% |
| Monday Night | 60°F | Mostly Clear | 0 to 10 mph SSW | 1% |
| Tuesday | 80°F | Sunny | 0 to 10 mph SSW | 0% |
| Tuesday Night | 61°F | Mostly Clear | 0 to 10 mph WNW | 0% |
| Wednesday | 87°F | Sunny | 0 to 10 mph WSW | 0% |
| Wednesday Night | 64°F | Mostly Clear | 0 to 10 mph SW | 3% |
| Thursday | 88°F | Sunny | 0 to 10 mph SSW | 2% |
| Thursday Night | 65°F | Mostly Clear | 0 to 10 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Diamond Bar, CA
Last spring frost
Jan 8
First fall frost
Dec 28
Growing season
354 days
Hardiness zone
10a
Explore more for Diamond Bar, CA: full frost dates · planting calendar · California frost dates
Climate data from the nearest NOAA station, Pomona/Fairplex, Ca (7.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.