Current Conditions

Diamond Bar, California

70°F21°C

Clear

Wind

SW 3 mph5 km/h

Humidity

69%

Cloud Cover

As of Tuesday, September 22, 2026 at 7:51 PM PDT

Today's Outlook

Night

Mostly clear, with a low around 64°F18°C. Light wind from the SSE around 2 mph3 km/h.

7-Day Forecast

Condition	High (°F)	Low (°F)	Precip (mm)	Cloud Cover (%)	Wind (mph)
Clear	High 87°F31°C	Low 64°F18°C	Precip 0 in0 mm—	Cloud 4%	Wind SW 3 mph5 km/h	Wednesday: Mostly clear and hot, with a high of 87°F31°C and morning low of 68°F20°C. Light wind from the SW around 5 mph7 km/h. Wednesday Night: Mostly clear, with a low around 64°F18°C. Light wind from the SSE around 2 mph3 km/h.
Clear	High 86°F30°C	Low 65°F19°C	Precip 0 in0 mm—	Cloud 9%	Wind SW 3 mph5 km/h	Thursday: Mostly clear and warm, with a high of 86°F30°C and morning low of 69°F21°C. Light wind from the SW around 4 mph7 km/h. Thursday Night: Mostly clear, with a low around 65°F19°C. Light wind from the WNW around 2 mph3 km/h.
Clear	High 88°F31°C	Low 66°F19°C	Precip 0 in0 mm—	Cloud 36%	Wind SW 3 mph5 km/h	Friday: Partly cloudy and hot, with a high of 88°F31°C and morning low of 70°F21°C. Light wind from the SW around 4 mph7 km/h. Friday Night: Partly cloudy, with a low around 66°F19°C. Light wind from the W around 2 mph3 km/h.
Partly Cloudy	High 88°F31°C	Low 67°F19°C	Precip 0 in0 mm—	Cloud 66%	Wind SSW 3 mph5 km/h	Saturday: Mostly cloudy and hot, with a high of 88°F31°C and morning low of 70°F21°C. Light wind from the SSW around 4 mph7 km/h. Saturday Night: Mostly cloudy, with a low around 67°F19°C. Light wind from the SE around 2 mph3 km/h.
Drizzle	High 80°F27°C	Low 67°F20°C	Precip 0.06 in1.4 mm13%	Cloud 63%	Wind SSW 3 mph5 km/h	Sunday: Mostly cloudy and warm, with a high of 80°F27°C and morning low of 71°F21°C. Light wind from the SSW around 4 mph7 km/h. 13% chance of drizzle throughout the day. Sunday Night: Mostly cloudy, with a low around 67°F20°C. Light wind from the SW around 2 mph3 km/h.
Drizzle	High 81°F27°C	Low 64°F18°C	Precip 0.04 in1.1 mm10%	Cloud 31%	Wind SW 3 mph5 km/h	Monday: Partly cloudy and warm, with a high of 81°F27°C and morning low of 67°F19°C. Light wind from the SW around 4 mph7 km/h. 10% chance of drizzle throughout the day. Monday Night: Partly cloudy, with a low around 64°F18°C. Light wind from the WSW around 2 mph3 km/h.
Clear	High 86°F30°C	Low 62°F17°C	Precip 0.02 in0.6 mm9%	Cloud 12%	Wind WSW 3 mph5 km/h	Tuesday: Mostly clear and hot, with a high of 86°F30°C and morning low of 68°F20°C. Light wind from the SW around 4 mph7 km/h. Tuesday Night: Mostly clear, with a low around 62°F17°C. Light wind from the NNE around 2 mph4 km/h.

15-Day Forecast

	Day	High	Low	Precip	Cloud Cover	Condition	Wind
	WednesdaySep 23	87°F31°C	64°F18°C	0 in0 mm· —	4%	Clear	SW 3 mph5 km/h
DayMostly clear and hot, with a high of 87°F31°C and morning low of 68°F20°C. Light wind from the SW around 5 mph7 km/h. NightMostly clear, with a low around 64°F18°C. Light wind from the SSE around 2 mph3 km/h.
	ThursdaySep 24	86°F30°C	65°F19°C	0 in0 mm· —	9%	Clear	SW 3 mph5 km/h
DayMostly clear and warm, with a high of 86°F30°C and morning low of 69°F21°C. Light wind from the SW around 4 mph7 km/h. NightMostly clear, with a low around 65°F19°C. Light wind from the WNW around 2 mph3 km/h.
	FridaySep 25	88°F31°C	66°F19°C	0 in0 mm· —	36%	Clear	SW 3 mph5 km/h
DayPartly cloudy and hot, with a high of 88°F31°C and morning low of 70°F21°C. Light wind from the SW around 4 mph7 km/h. NightPartly cloudy, with a low around 66°F19°C. Light wind from the W around 2 mph3 km/h.
	SaturdaySep 26	88°F31°C	67°F19°C	0 in0 mm· —	66%	Partly Cloudy	SSW 3 mph5 km/h
DayMostly cloudy and hot, with a high of 88°F31°C and morning low of 70°F21°C. Light wind from the SSW around 4 mph7 km/h. NightMostly cloudy, with a low around 67°F19°C. Light wind from the SE around 2 mph3 km/h.
	SundaySep 27	80°F27°C	67°F20°C	0.06 in1.4 mm· 13%	63%	Drizzle	SSW 3 mph5 km/h
DayMostly cloudy and warm, with a high of 80°F27°C and morning low of 71°F21°C. Light wind from the SSW around 4 mph7 km/h. 13% chance of drizzle throughout the day. NightMostly cloudy, with a low around 67°F20°C. Light wind from the SW around 2 mph3 km/h.
	MondaySep 28	81°F27°C	64°F18°C	0.04 in1.1 mm· 10%	31%	Drizzle	SW 3 mph5 km/h
DayPartly cloudy and warm, with a high of 81°F27°C and morning low of 67°F19°C. Light wind from the SW around 4 mph7 km/h. 10% chance of drizzle throughout the day. NightPartly cloudy, with a low around 64°F18°C. Light wind from the WSW around 2 mph3 km/h.
	TuesdaySep 29	86°F30°C	62°F17°C	0.02 in0.6 mm· 9%	12%	Clear	WSW 3 mph5 km/h
DayMostly clear and hot, with a high of 86°F30°C and morning low of 68°F20°C. Light wind from the SW around 4 mph7 km/h. NightMostly clear, with a low around 62°F17°C. Light wind from the NNE around 2 mph4 km/h.
	WednesdaySep 30	89°F32°C	64°F18°C	0.02 in0.4 mm· 4%	21%	Clear	SW 3 mph6 km/h
DayMostly clear and hot, with a high of 89°F32°C and morning low of 68°F20°C. Light wind from the SW around 5 mph7 km/h. Dry air. NightMostly clear, with a low around 64°F18°C. Light wind from the NE around 2 mph4 km/h.
	ThursdayOct 1	87°F31°C	66°F19°C	0.04 in1.1 mm· 7%	29%	Clear	SW 3 mph6 km/h
DayPartly cloudy and hot, with a high of 87°F31°C and morning low of 69°F20°C. Light wind from the SW around 5 mph7 km/h. NightPartly cloudy, with a low around 66°F19°C. Light wind from the NE around 2 mph4 km/h.
	FridayOct 2	87°F31°C	66°F19°C	0.02 in0.5 mm· 6%	19%	Clear	SW 3 mph5 km/h
DayMostly clear and hot, with a high of 87°F31°C and morning low of 69°F20°C. Light wind from the SW around 4 mph7 km/h. NightMostly clear, with a low around 66°F19°C. Light wind from the NE around 2 mph4 km/h.
	SaturdayOct 3	87°F31°C	65°F18°C	0.01 in0.3 mm· 5%	16%	Clear	SSW 3 mph6 km/h
DayMostly clear and hot, with a high of 87°F31°C and morning low of 68°F20°C. Light wind from the SW around 4 mph7 km/h. Dry air. NightMostly clear, with a low around 65°F18°C. Light wind from the NE around 2 mph4 km/h.
	SundayOct 4	88°F31°C	65°F18°C	0.02 in0.5 mm· 2%	17%	Clear	SW 4 mph6 km/h
DayMostly clear and hot, with a high of 88°F31°C and morning low of 69°F20°C. Light wind from the SW around 5 mph7 km/h. Dry air. NightMostly clear, with a low around 65°F18°C. Light wind from the NNE around 3 mph4 km/h.
	MondayOct 5	89°F31°C	65°F18°C	0.01 in0.2 mm· 3%	14%	Clear	WSW 4 mph6 km/h
DayMostly clear and hot, with a high of 89°F31°C and morning low of 68°F20°C. Light wind from the SW around 4 mph7 km/h. Dry air. NightMostly clear, with a low around 65°F18°C. Light wind from the NNE around 3 mph4 km/h.
	TuesdayOct 6	90°F32°C	66°F19°C	0.01 in0.2 mm· 5%	13%	Clear	NW 4 mph6 km/h
DayMostly clear and hot, with a high of 90°F32°C and morning low of 70°F21°C. Light wind from the SW around 5 mph7 km/h. Dry air. NightMostly clear, with a low around 66°F19°C. Light wind from the NNE around 3 mph4 km/h.
	WednesdayOct 7	89°F32°C	67°F19°C	0.01 in0.2 mm· 5%	18%	Clear	SW 4 mph6 km/h
DayMostly clear and hot, with a high of 89°F32°C and morning low of 70°F21°C. Light wind from the SW around 5 mph7 km/h. Dry air. NightMostly clear, with a low around 67°F19°C. Light wind from the NNE around 3 mph4 km/h.

Nearby Cities

Walnut3 mi5 km Pomona4 mi6 km Chino Hills4 mi6 km San Dimas5 mi9 km South San Jose Hills6 mi9 km La Verne6 mi9 km

About This Forecast

This forecast is powered by WeatherMesh, the world's most advanced and accurate weather model powered by AI. WeatherMesh is built on proprietary data from WindBorne's Global Sounding Balloon constellation — the world's largest fleet of autonomous, long-duration weather balloons — collecting observations across 100% of Earth, including over oceans and remote regions where no other data exists.

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Coordinates: 34.0286°N, 117.8103°W·Elevation: 212m·Timezone: America/Los_Angeles·Population: 56,897