The watch will be in effect from 11 a.m. Tuesday through 8 p.m. Thursday.
It warns of dangerously hot conditions with temperatures from 95 to 103 degrees possible resulting in major heat risk.
Forecasters said the highest heat risk will be in the eastern portion of the county.
At the same time, there also is a forecast of winds, with gusts above 20 miles per hour.
Temperatures will roll back into the high 80s to low 90s from Friday into the weekend, according to the forecast.
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