Then, true to form for summer 2010, the mercury is expected to slide to 88 by Friday and 76 on Sunday, the National Weather Service said.
A buildup of high pressure is bringing the brief hot spell, according to the agency. The high pressure has stayed east for most of the summer, which has cooled the Central Valley and heated up other parts of the nation, a forecaster said last week.
Modesto's average daily highs were about 3 degrees less than the norm in July and the first three weeks of August. Most of the days were plenty warm, but there were few scorchers.
Health experts advise residents to beware of heat stress and more serious conditions that can result from too much time in the sun. People working or playing outdoors should have access to drinking water and shade and take breaks if they feel overcome by the heat.
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The warning is especially important when a hot day follows a long mild spell, because people might not be acclimated to the heat.