"Exceptionally dangerous" heat wave still in early stages; record temps possible

Day two of a dangerous heat wave in the Bay Area and Northern California will see more widespread triple-digit temperatures Wednesday and possibly multiple records being broken, forecasters said.

The extreme heat will be most evident in inland areas and higher elevations and triple-digit afternoon temperatures are expected into early next week. The National Weather Service says an Excessive Heat Warning has been extended until July 9 for most of the Bay Area and until July 11 for portions of the Central Valley.

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In a forecast discussion, the Weather Service noted the prolonged heat wave can be life-threatening if precautions are not taken.

"It cannot be stressed enough that this is an exceptionally dangerous and lethal situation. It may not seem so if you live near the coast, but an event of this scale, magnitude, and longevity will likely rival anything we've seen in the last 18 years for inland areas, the Weather Service said. "Several days of temperatures well above normal and little relief overnight will lead to compounding effects among people and infrastructure, with the possibility of numerous heat related fatalities and rolling black outs."

Residents are advised to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Find a list of Bay Area cooling centers here .

Relief from the heat can still be found near the water. Daytime highs will be mostly in the upper 60s to 80s on the coast, 70s to 90s around the bay, and up to 110 inland. The Weather Service said the Bay Area's natural air conditioning won't extend as far inland Wednesday because of building high pressure.

The Weather Service also said critical fire weather conditions will continue through the week until at least Friday. A Red Flag Warning is in effect for higher elevations of the North Bay, East Bay hills, and the Santa Cruz Mountain through 5 a.m. Friday.

The dangerous heat has led Antioch to cancel its Fourth of July parade, Antioch police announced Tuesday .

The rest of the celebration will continue at 6 p.m. Thursday in "historic Rivertown" when things start to cool down. The city will host rides and games, food trucks, live music, a dunk tank, and more.

The fireworks show is still scheduled to go off over the Delta, beginning at 9:15 p.m.

St. Helena on Tuesday announced it would postpone its fireworks show to a later date due to the fire danger presented by the heat wave, but the city will still host a community 4th of July celebration at Crane Park beginning at 6 p.m.

The fire danger was evident Tuesday with several large fires in the Bay Area and Northern California, including the Thompson Fire in Butte County that forced some 3,000 people to evacuate, and the Toll Fire in Napa County just north of Calistoga, and the Denverton Fire in Solano County .

The high fire risk prompted the East Bay Regional Park District to close hills and inland parks Tuesday through Friday morning, while shoreline parks and swim facilities remained open. In Concord, the city closed its open space areas, including Lime Ridge Open Space and trails within Newhall Community Park Tuesday through Wednesday evening at the recommendation of the Contra Costa County Fire Protection District.

The combination of low relative humidity, dry fuels, the 4th of July holiday, and wind gusts of up to 35 mph along ridgetops and higher peaks are all contributing to the fire danger.

The fire risk prompted Pacific Gas and Electric to initiate another round of public safety power outages in areas of the Bay Area and Northern California with high fire risk. About 2,200 PG&E customers were without power Wednesday morning and by the early afternoon PG&E issued a weather "all-clear" to begin assessing its equipment and restoring service.