heat wave

Dangerous heat wave threatens much of US... except in the Bay Area

ByMike Nicco KGO logo

Thursday, July 21, 2022

Heat wave threatens much of US... except the Bay Area

You can thank our cool ocean and hot Central Valley for protecting the Bay Area from extreme heat threatening much of the country.

SAN FRANCISCO (KGO) -- You can thank our cool ocean and hot Central Valley for protecting the Bay Area from extreme heat threatening much of the country.

More than 100 million Americans may endure dangerous heat the next seven days. This current heat wave stretches across 25 states, from California to Maine.

The heat index, the temperature our body perceives as it tries to cool us, soars well above 100 degrees.

Increasing humidity inhibits our body's ability to cool us. The heat index measures this and tells us the temperature our body really feels.

These extreme hot and humid conditions develop across the Southern Plains, Deep South and from Washington D.C. through Philadelphia to New York City.

VIDEO: What is a heat wave? How heat waves form and temperatures climb

It's hotter than normal, and it has been like this for several days. What you're experiencing is a heat wave. How did it form?

You know who wants no part of this? San Francisco and most of our Bay Area neighborhoods.

We have a unique summer circulation, our free air conditioning, thanks to our cool Pacific Ocean and hot Central Valley.

You will find our coolest conditions and heaviest air closer to the area of origination (Pacific Ocean). The warmest and lightest air develops over the Central Valley.

VIDEO: Heat stroke or heat exhaustion: Do you know the difference?

Though heat-related deaths and illness are preventable, the CDC says many people still succumb to extreme heat every year. Here's a look at the differences between heat stroke and heat exhaustion, and how to treat those affected.

Our morning sunshine breaks free from the retreating cloud deck faster from east to west. Earlier sunshine creates warmer ground and rising air. As the hotter and lighter air rises, it creates a vacuum which the cooler and heavier air fills. This turns on our free air conditioning circulation

Unfortunately for those who live closer to the Central Valley, this journey east progressively warms the air as it travels over warmer ground. This creates our average summer spread of 25 from the Coast to Inland.