Summer -- which "officially" ends in 11 days -- is hanging on with a vengeance, according to the National Weather Service, with a daytime high temperature today that will soar to about 90 degrees.

The sudden return of hot and humid weather has also triggered an air-quality alert from 11 a.m. to 11 p.m. today, with state officials warning that conditions could generate unhealthy ozone levels.

Otherwise, skies will be sunny today, with a southwest wind 5 to 10 mph.

Tonight, there is a 20 percent chance of isolated showers and thunderstorms as clouds move in and the temperature dips to a low of about 70 degrees.

Tomorrow, the odds of showers and thunderstorms increase to 50 percent, mainly after noon, the NWS says. Skies will be partly sunny, with a high temperature in the low-80s. Overnight, there is a 60 percent chance of precipitation, with a low temperature in the low-60s.

On Friday, there is a 30 percent chance of scattered showers before 9 a.m. Skies will gradually become sunny and the daytime high temperature will be in the mid-70s. Nighttime will be partly cloudy, with a low around temperature about 50 degrees.

Saturday should be sunny with a high temperature in the upper-60s. Nighttime will be mostly clear, with a low temperature about 50 degrees.

The outlook for Sunday, according to the weather service, is sunny and temperatures about 70 degrees.