Live Weather & Forecast

Weather in Diamond Bar

California, United States · Real-time conditions & 3-day outlook

Flag of United States
Partly cloudy
14°C
Feels like 13°C
58°F / Feels 56°F
Partly cloudy
Diamond Bar, California
🌞 Daytime
Updated: 2026-04-12 11:45
💧
Humidity
88%
💨
Wind
13 km/h SW
🌬️
Wind Gust
19.3 km/h
🌡️
Pressure
1016 mb
👁️
Visibility
11 km
☀️
UV Index
3.6 (Moderate)
🌧️
Precipitation
2.71 mm
☁️
Cloud Cover
75%
💦
Dew Point
12.5°C
🌐
Wind Degree
224°

Air Quality Index

US EPA: Good UK DEFRA: Low (1)
CO
173.9 μg/m³
NO₂
12.8 μg/m³
O₃
96 μg/m³
SO₂
6.7 μg/m³
PM 2.5
8.8 μg/m³
PM 10
11.2 μg/m³

Weather Alerts 5

Met · Moderate · Expected
Winter Weather Advisory issued April 11 at 8:36PM PDT until April 13 at 11:00AM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Wet snow expected. Total snow accumulations up to around 6 inches above 6000 feet. Winds gusting as high as 45 mph. * WHERE...Eastern San Gabriel Mountains, Interstate 5 Corridor, and Western San Gabriel Mountains and Highway 14 Corridor. * WHEN...From 3 AM Sunday to 11 AM PDT Monday. * IMPACTS...The hazardous conditions could impact the Monday morning commute. Gusty winds could bring...

Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1.

Effective: 2026-04-11T20:36:00-07:00  ·  Expires: 2026-04-12T11:00:00-07:00
Met · Moderate · Expected
Wind Advisory issued April 11 at 7:00PM PDT until April 12 at 10:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Southwest winds 20 to 30 mph with gusts up to 45 mph expected. Isolated gusts to around 55 mph near Lake Palmdale. * WHERE...Antelope Valley Foothills. * WHEN...From 3 AM to 10 PM PDT Sunday. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution.

Effective: 2026-04-11T19:00:00-07:00  ·  Expires: 2026-04-12T07:00:00-07:00
Met · Moderate · Expected
Special Weather Statement issued April 12 at 4:43AM PDT by NWS Los Angeles/Oxnard CA

At 442 AM PDT, Doppler radar was tracking gusty showers across portions of Ventura and Los Angeles Counties moving northeast at 25 mph. HAZARD...Wind gusts up to 40 mph. SOURCE...Radar indicated. IMPACT...Gusty winds could knock down tree limbs and blow around unsecured objects. Locations impacted include... Oxnard... Thousand Oaks... Simi Valley... Eastern Ventura... Camarillo... Fillmore......

If outdoors, consider seeking shelter inside a building.

Effective: 2026-04-12T04:43:00-07:00  ·  Expires: 2026-04-12T05:45:00-07:00
Met · Moderate · Expected
Winter Weather Advisory issued April 12 at 12:40AM PDT until April 13 at 11:00AM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Wet snow expected. Total snow accumulations up to around 6 inches above 6000 feet. Winds gusting as high as 45 mph. * WHERE...Eastern San Gabriel Mountains, Interstate 5 Corridor, and Western San Gabriel Mountains and Highway 14 Corridor. * WHEN...Until 11 AM PDT Monday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Monday morning commute. Gust...

Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1.

Effective: 2026-04-12T00:40:00-07:00  ·  Expires: 2026-04-12T17:00:00-07:00
Met · Moderate · Expected
Wind Advisory issued April 12 at 12:39AM PDT until April 12 at 10:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Southwest winds 20 to 30 mph with gusts up to 45 mph expected. Isolated gusts to around 55 mph near Lake Palmdale. * WHERE...Eastern Antelope Valley Foothills and Western Antelope Valley Foothills. * WHEN...Until 10 PM PDT this evening. * IMPACTS...Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result.

Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution.

Effective: 2026-04-12T00:39:00-07:00  ·  Expires: 2026-04-12T22:00:00-07:00

Today's Hourly Forecast

24-hour breakdown for Diamond Bar, California

12 AM
Overcast
14°
Overcast
💧 82% 💨 10.4 km/h
1 AM
Cloudy
13°
Cloudy
💧 78% 💨 10.1 km/h
2 AM
Clear
13°
Clear
💧 83% 💨 11.5 km/h
3 AM
Light rain
13°
Light rain
💧 92% 💨 12.6 km/h 🌧️ 100%
4 AM
Light rain
13°
Light rain
💧 92% 💨 12.2 km/h 🌧️ 100%
5 AM
Cloudy
13°
Cloudy
💧 91% 💨 10.1 km/h
6 AM
Partly Cloudy
13°
Partly Cloudy
💧 92% 💨 10.8 km/h
7 AM
Sunny
13°
Sunny
💧 92% 💨 11.9 km/h
8 AM
Sunny
14°
Sunny
💧 85% 💨 13.3 km/h
9 AM
Sunny
14°
Sunny
💧 81% 💨 11.9 km/h
10 AM
Patchy rain nearby
14°
Patchy rain nearby
💧 77% 💨 11.2 km/h 🌧️ 88%
11 AM
Partly cloudy
14°
Partly cloudy
💧 88% 💨 13 km/h 🌧️ 100%
12 PM
Moderate rain at times
14°
Moderate rain at times
💧 85% 💨 15.1 km/h 🌧️ 100%
1 PM
Patchy rain nearby
14°
Patchy rain nearby
💧 77% 💨 17.3 km/h 🌧️ 100%
2 PM
Patchy rain nearby
15°
Patchy rain nearby
💧 77% 💨 19.4 km/h 🌧️ 100%
3 PM
Partly Cloudy
15°
Partly Cloudy
💧 64% 💨 22.3 km/h
4 PM
Partly Cloudy
15°
Partly Cloudy
💧 59% 💨 22.3 km/h
5 PM
Partly Cloudy
15°
Partly Cloudy
💧 58% 💨 21.6 km/h
6 PM
Sunny
14°
Sunny
💧 58% 💨 19.4 km/h
7 PM
Partly Cloudy
13°
Partly Cloudy
💧 65% 💨 16.9 km/h
8 PM
Clear
12°
Clear
💧 69% 💨 15.5 km/h
9 PM
Partly Cloudy
11°
Partly Cloudy
💧 72% 💨 13.3 km/h
10 PM
Partly Cloudy
13°
Partly Cloudy
💧 75% 💨 11.5 km/h
11 PM
Partly Cloudy
11°
Partly Cloudy
💧 61% 💨 10.8 km/h

3-Day Forecast

Daily overview for Diamond Bar, California

Today
Moderate rain
Moderate rain
16° / 11°
🌧️ 88% chance of rain
💧 Avg. humidity: 77%
💨 Max wind: 22.3 km/h
🌧️ Total precip: 8.06 mm
☀️ UV Index: 1.3
🌅 Sunrise: 06:24 AM
🌇 Sunset: 07:21 PM
🌙 Waning Crescent
🌑 Moon: 33% lit
Mon, Apr 13
Partly Cloudy
Partly Cloudy
14° / 8°
🌧️ 0% chance of rain
💧 Avg. humidity: 70%
💨 Max wind: 22.3 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.5
🌅 Sunrise: 06:22 AM
🌇 Sunset: 07:22 PM
🌙 Waning Crescent
🌑 Moon: 23% lit
Tue, Apr 14
Sunny
Sunny
20° / 8°
🌧️ 0% chance of rain
💧 Avg. humidity: 68%
💨 Max wind: 17.6 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.8
🌅 Sunrise: 06:21 AM
🌇 Sunset: 07:22 PM
🌙 Waning Crescent
🌑 Moon: 15% lit

Best Time to Visit Diamond Bar

Plan your trip to Diamond Bar, United States around the most favorable weather conditions.

Peak Season
June – September
Warm, dry summers — ideal for outdoor activities.
Shoulder Season
April – May, October
Fewer crowds, moderate prices, mild weather.
Off Season
November – March
Cooler temperatures; some regions may experience rain or snow.
← Back to Diamond Bar 🗓 View Holidays 2026

Frequently Asked Questions

What is the current weather in Diamond Bar?
Current conditions in Diamond Bar: Partly cloudy, temperature 14°C, humidity 88%.
What is the best time to visit Diamond Bar?
The best time to visit Diamond Bar is typically June – September. Warm, dry summers — ideal for outdoor activities.
What is the climate like in Diamond Bar?
Diamond Bar is located at approximately 34° latitude. It has a temperate climate with warm summers and cold winters.
Does it rain a lot in Diamond Bar?
The wettest period in Diamond Bar is typically during November – March. Cooler temperatures; some regions may experience rain or snow.
What should I pack for a trip to Diamond Bar?
For visits to Diamond Bar during June – September: light clothing and sun protection. For November – March: layers and a waterproof jacket are recommended.
What country is Diamond Bar in?
Diamond Bar is located in United States, in the state of California.
What are the public holidays in Diamond Bar in 2026?
View the 2026 public holidays for Diamond Bar on our Holidays page.
What are the GPS coordinates used for the weather forecast in Diamond Bar?
The weather forecast for Diamond Bar uses coordinates 34.0286, -117.8103.