A Fourth of July Scorcher on Tap for Bay Area and California

The heat goes on, the heat goes on.

A lengthy heat wave is set to hit California and the Bay Area just before July Fourth, and forecasters are warning that it could be the most significant of the summer thus far.

Bay Area temperatures will rise into the 90s and low 100s, with the hottest days being Tuesday through Thursday of next week, according to National Weather Service forecasts. Conditions will be hot the following weekend, too.

The heat will be especially dangerous in the Central Valley and portions of the Sierra foothills, with highs at or above 110 degrees possible in the northern Sacramento Valley on Wednesday, according to the latest forecast discussion from the weather service’s Sacramento office.

An excessive heat watch for the Central Valley begins Monday and extends until Friday, with a significantly elevated risk of heat-related illness.

By July Fourth, that danger could become even more widespread through much of the valley due to high overnight temperatures and winds.

“Little relief expected overnight with 70s to 80s in portions of the Central Valley and foothills,” the weather service said. “Areas of gusty northerly wind Tuesday into Wednesday in the Central Valley and adjacent foothills could result in periods of critical fire weather conditions.”

In their latest outlook, fire officials warn that the wildfire risk for most of the valleys and foothill areas of Northern California will elevate into the moderate category by Tuesday, a result of a combination of heat and increasingly dried-out grasses and shrubs. And with the vast majority of fires being human-caused, July Fourth fireworks, grills, bonfires or some combination bring their own dangers.

“Holiday week … typically has lots of ignitions; therefore, risk potential will increase,” the National Interagency Fire Center warned.

A combination of low relative humidity and high temperatures will lead to “widespread elevated fire weather concerns” across the inland Bay Area starting Tuesday, the weather service said. Gusty winds could add to the risk for the interior North Bay Mountains and East Bay Hills.

Forecasters do not yet know exactly how hot it will be closer to the water in the interior Bay Area and whether the steamy temperatures will extend all the way to the ocean. That’s not very common for this time of year when it’s typically foggy and cool near the coast because of air off the water.