The driest water year in nearly a decade ended Tuesday in San Diego, which recorded 5.07 inches of precipitation, barely half its seasonal average, the National Weather Service said.
The shortage of rain has produced varying levels of drought across the county, elevating the risk of wildfires at the time of year when dry Santa Ana winds begin to blow.
San Diego hasn’t been this dry since the water year that ended on Sept. 30, 2018, when the city got 3.34 inches of rain. The water year is a 12-month cycle that begins on Oct. 1, when the state is headed into fall and winter, when most rainfall occurs.
The county also recently finished an unusually cool summer. The monthly average temperature in San Diego in June, July, August and September was below normal.
“We didn’t get much monsoonal moisture, which brings in warmer air,” said Paul Steward, a weather service forecaster.
Winds out of the south-southwest also pushed warmer surface water in the ocean away from the coast, allowing cooler water to rise, a phenomenon known as upwelling. At times, sea surface temperatures were in the low 60s, nearly 10 degrees below average.
Originally Published: October 1, 2025 at 3:07 PM PDT