Diamond Bar Weather in September

Diamond Bar in September averages 32°C (90°F) during the day and 17°C (63°F) at night. Minimal rainfall is typical for this time of year.

Rainfall in Diamond Bar in September

Historically, approximately a single day this month are expected to have rain, averaging 4.9 mm (0.2 in). Any rain that does arrive is likely to be fairly light and short-lived.

Temperature in Diamond Bar in September

The perfect temperature in Diamond Bar in September makes it a solid month to visit, with 32°C (90°F) during the day and 17°C (63°F) at night. Sunshine and humidity can make it feel even warmer than the raw temperature suggests. Nights drop to around 17°C (63°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.

Sunshine in Diamond Bar in September

Expect sunny days throughout the month, with an estimated 290 hours of sunshine. This makes it a pleasant time to visit Diamond Bar.

Should you favor a climate that's both dry and comfortably warm, January, February, March, April, May, October and November typically offer the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

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• January
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For a detailed overview over the year and the best time to visit the United States of America, check out our Diamond Bar's climate page.

Diamond Bar Temperature in September

Min Temperature 17°C (63°F)  

Max Temperature 32°C (90°F)  

Chance of Rain 3%  

Precipitation 4.9 mm (0.2 in)  

Rainy days a single day  

Sunshine 290 hours *  

Percentage Sunshine *  

* Data from: Corona, the United States of America (28 KM, 17 Miles).

What to Wear in Diamond Bar in September

Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. With minimal rainfall expected, you can leave the rain gear at home. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Diamond Bar in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

10/10

Cycling

8/10

Walking

8/10

Barbeque

10/10

Camping

10/10

Outdoor sports

8/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Diamond Bar's climate page.

More climate data for Diamond Bar

Temperature Rainfall Sunshine

See the full Diamond Bar climate overview or explore weather in the United States of America.