Hot, muggy weather on Tuesday greeted the unofficial first day of fall, with heat index values expected to reach the mid-90s and possible afternoon or evening storms.
Baltimore city and Baltimore, Arundel, Carroll, Harford and Howard counties are under a severe thunderstorm watch until 10 p.m.
Wednesday is forecast to be slightly less hot and humid, with highs around 90 and dew points in the mid-60s, and partly cloudy skies.
Thursday is forecast to be pleasant with sunny skies, low humidity and highs in the upper 80s.
Humidity returns Friday, with highs again in the upper 80s.