Diamond Bar, CA Weather Forecast
Local 7-day forecast
Mostly Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for Diamond Bar, CA in one place.
Mostly sunny, with a high near 80.
Local Weather Overview
This forecast page for Diamond Bar, CA is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Apr 15, 2026 9:29 AM PDT.
The active forecast window currently covers Apr 19 to Apr 21, 2026 for Diamond Bar, CA.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Apr 19 to Apr 21, 2026
- Latest sync
- Apr 15, 2026 9:29 AM PDT
- Forecast office
- LOX
- Source
- NOAA / NWS
Daily Outlook
This Week in Diamond Bar
Sunday looks like the warmest upcoming period in Diamond Bar at 80 degrees F.
Sunday Night is the coolest period ahead with temperatures near 53 degrees F.
The strongest winds are forecast for Sunday at about 0 to 10 mph S.
The forecast from Apr 19 through Apr 21 stays mostly dry.
Forecast Details
- Last updated
- Apr 15, 2026 9:29 AM PDT
- Coverage
- 4 days
- Time zone
- America/Los_Angeles
- Forecast office
- LOX
- Radar station
- KSOX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Mostly clear, with a low around 53.
Sunny, with a high near 75.
Mostly clear, with a low around 53.
Mostly sunny, with a high near 72.
Partly cloudy, with a low around 53.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Sunday
Apr 19
|
Mostly Sunny
|
80°F |
0 to 10 mph
S
|
|
Sunday Night
Apr 19
|
Mostly Clear
|
53°F |
0 to 10 mph
SSW
|
|
Monday
Apr 20
|
Sunny
|
75°F |
0 to 10 mph
SSW
|
|
Monday Night
Apr 20
|
Mostly Clear
|
53°F |
0 to 10 mph
SSW
|
|
Tuesday
Apr 21
|
Mostly Sunny
|
72°F |
0 to 10 mph
SSW
|
|
Tuesday Night
Apr 21
|
Partly Cloudy
|
53°F |
0 to 10 mph
SSW
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Diamond Bar.
