Another scorcher Saturday, but relief arrives Sunday

Weather Underground predicts a high temperature of 104 degrees today, with a 40 percent chance of rain or thunderstorms. The "heat index"—how it will feel, including the humidity—is forecast for 111. Weather.com predicts today's high to be 98, with a 30 percent chance of rain.

The National Weather Service has issued an excessive heat warning in effect until 8 p.m. today. NWS advises, "Take extra precautions... if you work or spend time outside. When possible... reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose fitting clothing when possible and drink plenty of water.

"To reduce risk during outdoor work... the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency - call 911."

The average high for this date is 83; the record is 101, set in 1988.

Rain is likely (60 percent chance) overnight, with a low temperature of 64, according to Weather Underground. Weather.com has the overnight rain chance at 30 percent.

The heat is expected to break on Sunday, with a forecast high of 84. Highs in the 80s are expected for the next several days, with lows dipping into the 50s starting Sunday night.

Full weather information is always available on the AnnArbor.com weather page.