After expected showers move on today and overnight, temperatures will start to rise, delivering what could be the first heat wave in nearly 10 months -- right on time for June 1.

The National Weather Service is forecasting a near 90 percent chance of showers today, and they could be heavy at times.

Then things heat up and the . Wednesday's high could reach 88 under partly sunny skies, as the Phillies begin a two-game series against the Red Sox at the Citizens Bank Park.

Temperatures Thursday through Saturday are expected to reach into the low 90s with sunny skies.

There hasn't been a heat wave — three straight days of 90 or more — since early August.
Philadelphia's hottest day so far this year was April 10, which hit 89, and the last time the temperature hit 90 in Philadelphia was Sept. 1.

The forecast calls for a slight dip on Sunday with an expected high of about 88 and a chance of thunderstorms.

For more on the forecast, see Philly.com's weather page.