Dangerously hot temperatures are in the forecast for the San Diego County desert communities with highs above 110 degrees expected over the weekend and into next week.

An excessive heat warning has been issued by the National Weather Service from Saturday to Thursday in local deserts. Highs are expected to reach 114 and could lead to heat-related illness.

The temperatures will also be high in the valleys and mountains in San Diego County, prompting a heat advisory from 10 a.m. to 8 p.m. on Saturday.

It will be between 95 and 100 near the foothills on Saturday, but the conditions will be cooler on Sunday with a slight chance of showers and thunderstorms. Temperatures are expected to be between 90 and 100 in the mountain areas Saturday.

The coast should be more comfortable, in the high 70s to mid-80s.