Portland is officially sweating out its first heat wave in more than a decade.

On Tuesday, Portland’s high temperature of 94 degrees broke a record for Aug. 31 set in 1969.

That also put the city in the midst of its first official heat wave since July 1999, according to Steve Capriola, a meteorologist with the National Weather Service in Gray.

Capriola said a heat wave is defined as three consecutive days with highs of at least 90 degrees. Sunday’s high was 91 and Monday’s was 90.

And more hot weather is on the way. Capriola said temperatures today and Thursday will come close to 90 degrees.

Maine environmental officials also said air quality over the next several days is expected to be as bad as it’s been in several years.

Ground-level ozone concentrations are expected to reach unhealthy levels along the Maine coast starting today and into Thursday before they move inland.

The EPA recommends that people limit their strenuous outdoor activity over the next two days, particularly if they have respiratory conditions.

The demand for electricity is also expected to peak today, and homeowners are being urged to curb electrical consumption.