(CBS SF) — Heat sensitive residents of the Bay Area’s inland areas are at moderate to high risk of heat-related illnesses and higher fire danger as temperatures rise this weekend, National Weather Service officials said.

A heat advisory for the Diablo Range, Santa Cruz Mountains and Big Sur region was expanded to the East Bay valleys and North Bay Mountains, the weather service said Friday.

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The advisory is in effect from 8 a.m. Saturday to 9 p.m. Sunday for all five locations where temperatures could reach 105 degrees or more.

Cooler temperatures are forecast for early next week, weather officials said.

The hottest temperatures for inland valleys and ridges will be in the North Bay, East Bay, South Bay and in Monterey and Santa Cruz counties.

In the North Bay, interior valleys and ridges could reach the low 100s, according to weather officials.

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In the East Bay, interior valleys could reach the low 100s, while on East Bay ridges temperatures are forecast to reach the 90s.

The inland areas of the South Bay are forecast to reach the 90s while ridges will be near 100.

Inland valleys of Monterey and Santa Cruz counties are expected to be in the 90s. The ridges could reach the low 100s.

Temperatures from the North Bay coast to Santa Cruz will be lower, weather officials said.

Across the San Francisco and Monterey Bay areas temperatures in the hilly and mountainous regions could stay above 70 degrees during the night and early morning hours.

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