SIERRA MADRE (CBSLA) — A monsoonal weather pattern brought stifling heat, overcast skies and rain to Southern California Thursday.

The National Weather Service said Los Angeles County’s coasts and San Gabriel Valley could see light rain and possibly lightning, even as the Inland Empire braced for possible thunderstorms. The rain is the latest development in an ongoing heat wave, which brought triple-digit heat to several communities this week

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Rain was reported in the South Orange County area early Thursday morning. As the morning progressed, rain was spotted in the San Gabriel Valley communities of Monrovia and Sierra Madre.

The ongoing heat accompanied by the monsoonal moisture out of Mexico will make things feel hotter than what the thermometer shows, according to the NWS. Forecasters say people should be wary of heat-related illnesses by drinking plenty of fluids, staying in air-conditioned rooms and buildings and out of the sun, and not leaving people or pets in cars.

Riverside County’s mountains, metropolitan areas and the San Gorgonio Pass near Banning also have a good chance of seeing light showers and thunderstorms.

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The Inland Empire has been getting hit hard by this week’s heat wave, experiencing thunder, lighting and hail in some areas, and the city of Ontario hit a high of 108 degrees for the first time in 21 years.