By Reginald Stanley. Posted June 4, 2025, 9:48 PM.

An upper level low moving over the region from Baja California brought scattered showers and thunderstorms to parts of the region Tuesday evening.

The inland valleys of Riverside and San Bernardino counties, as well as portions of Orange and San Diego counties, were affected by a significant wave of unstable thunderstorms that formed over the mountains and deserts Tuesday afternoon, continuing into late Tuesday night. Precipitations amounts varied due to areas of locally heavy rain and thunderstorms, with Anza receiving the greatest total with 1.06 inches there. The National Weather Service had issued numerous Flash Flood Warnings throughout the evening. A cluster of particularly powerful thunderstorms transited over Anza, extending westward to the Temecula Valley, where rain totals were generally higher and numerous cloud-to-ground lightning strikes were observed. WeatherCurrents' station in Temecula is unavailable until further notice, however NWS data collected from the area suggests about 1/2 inch fell there. In Temecula Valley's Wine Country, a total of 0.75 inches was reported (courtesy of Jim Sappington). In Riverside's Canyon Crest neighborhood, 0.22 inches was observed (courtesy of Jim Ness).

Eastern valley locations were generally drier during this event, with totals under 1/10 inch in these areas. Simi Valley to the northwest managed to pick up 0.09 inches. WeatherCurrents' station in Pinon Hills was the only functioning station to not record measurable precipitation on Tuesday (Fallbrook's rain gauge is not functioning). Wednesday yielded calmer, milder weather under low pressure, with breezy conditions and an increasing marine layer dominating the latter half of Wednesday. Drizzle may be possible across inland areas and the coasts overnight. A warming trend is forecast to slowly build going into next week.

Here are the rain totals for the WeatherCurrents network and associates:

1. Season total began on October 1, 2024.