A new spate of extremely hot days is lining up to hit Fresno this week, starting with a forecast high Monday of 107 followed by 111 degrees on Tuesday and 108 on Wednesday, said Carlos Molina, a meteorologist with the National Weather Service in Hanford.

The month’s well-above average heat has been marked by multiple days of weather at or above 110 degrees, which Molina says is “rare.”

“Typically in Central California in years past, when we talked about heat waves, they were more in the realm of just below 105 degrees to maybe like 107, 108,” he said. “We rarely talked about it’s going to get to 110 or above 110.

“This is a rare event that we’re having more than one day where we’ve hit 110 or above. … Just the fact that that we’ve seen so many numbers actually going to 110, actually passing 110, is one of those kind of record events for us this July.”

What’s been missing this year is what meteorologists refer to as the “marine push,” when the cool marine layer builds up along the coast, rises to 3,000 feet and then pushes through Pacheco Pass and into the Valley, Molina said.

This summer the marine layer’s growth has stopped at about 2,000 feet, keep the cooler air on the coast and away from inland regions that are baking under high-pressure ridges, he said.

Westward Ho for the High-Pressure Ridge

The extreme heat event that’s returning this week is thanks to the high-pressure ridge that has been parked over the Four Corners region of the Southwest, where the four states of New Mexico, Arizona, Utah, and Colorado intersect, Molina said.

Disturbances to the east are pushing the high pressure back over California, where it will remain until a low-pressure system in the Pacific Northwest moves onshore and pushes the heat dome eastward again, bringing cooler weather this weekend to Fresno.

The high temperatures for Saturday and Sunday are forecast to be 97 degrees in Fresno. If such a cooldown becomes reality, it would be the lowest highs so far this month and the first time the high has only reached 97 since June 27, according to National Weather Service records.

This month is on track to be the hottest July ever. The record average temperature of 88.7 degrees was set in 2021. The average temperature is calculated as the midpoint between daily highs and lows. As of Sunday, Fresno’s average temperature for July was 91.4 degrees.

Stay Safe During Heat Wave

Molina continued to emphasize the importance of staying hydrated and being aware of heat illness symptoms during this week’s extreme heat event.

“It doesn’t take long for heat exhaustion to set in,” he said. “If you start to feel dizzy or tired, that is the onset of heat exhaustion. We always say, drink plenty of water, because even though you don’t think it’s affecting you, drinking that water really helps out.”