Heatwave, Coastal Hazards 4th Of July Week: Diamond Bar

DIAMOND BAR, CA — It's all heatwaves and high surf this week in Orange County and Los Angeles County, officials report. The National Weather Service has called for a "sprawling area of high pressure" slated to build over the Southwestern United States by Friday. That will contribute to hot weather for all areas except the immediate coast and the high elevation mountains, that agency said, including the areas of: San Gabriel Valley, Los Angeles County, Orange County Coastal Areas, Orange County Inland Areas, Huntington Beach, Costa Mesa, Santa Ana, Anaheim, Garden Grove, Irvine, Orange, Fullerton, and Mission Viejo.

Residents were warned of excessive high heat watch Friday morning through Saturday Evening, with temperatures between 85 and 95, and over 100 in some areas.

An Excessive Heat Watch means that a prolonged period of heat will create a dangerous situation in which increased occurrences of heat illnesses are likely.

"The combination of hot temperatures and high humidity will combine to create a dangerous situation in which heat illnesses are possible," the NWS said. "Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors."

Expect beach hazards as well this week, Wednesday through late Friday, the NWS said.

Swells from tropical cyclone Fabio will create elevated to high surf of 6-8 ft along south-facing beaches of Orange and northern San Diego Counties.

Isolated sets of 10-12 ft are possible. High surf and strong rip currents will make swimming hazardous during the period.

Strong high pressure building aloft will create excessive heat across all of SW CA Friday and Saturday. Highest temperatures are expected on Friday, with slightly lower highs on Saturday.

Remember to always swim near a lifeguard, and have a water watcher at all area pools.

7-day Forecast for Diamond Bar-Walnut

No precipitation throughout the week, with high temperatures rising to 107°F on Saturday.

Wednesday July 4

Partly cloudy in the morning. High 86, low 59.
Chance of precipitation: 0%. Wind 3 mph from the SW

Thursday July 5

Partly cloudy throughout the day. High 95, low 62.
Chance of precipitation: 0%. Wind 3 mph from the WSW

Friday July 6

Partly cloudy in the morning. High 106, low 73.
Chance of precipitation: 0%. Wind 2 mph from the NNW

Saturday July 7

Partly cloudy until afternoon. High 107, low 83.
Chance of precipitation: 0%. Wind 1 mph from the NNW

Sunday July 8

Mostly cloudy overnight. High 101, low 80.
Chance of precipitation: 0%. Wind 3 mph from the SW

Monday July 9

Mostly cloudy throughout the day. High 97, low 75.
Chance of precipitation: 0%. Wind 4 mph from the SW

Tuesday July 10

Mostly cloudy throughout the day. High 91, low 71.
Chance of precipitation: 0%. Wind 4 mph from the SW
Data provided by darksky.net.