Warm, muggy nights to last into the weekend along San Diego coastline

Sea surface temperatures are in the low 70s along the San Diego County coast
(Gary Robbins / The San Diego Union-Tribune )

The warm, humid weather that’s been making it hard for many people to sleep in greater San Diego’s coastal cities will last into the weekend and thunderstorms could return to the mountains on Thursday afternoon.

The National Weather Service says sea surface temperatures have risen into the low 70s, reducing the depth and duration of the marine layer in most areas. And a lot of monsoon moisture is arriving from northern Mexico.

Overnight temperatures will be in the upper 60s to low 70s.

“The monsoon is getting off to a better start than it did last year,” said Miguel Miller, a weather service forecaster.

The monsoon sparked a spectacular lightning show over much of inland San Diego County last weekend. Thursday’s lightning will be more sporadic and could extend into the desert.

The surf forecast is grim. There are no major swells arriving from the south, so the waves will remain in the 2- to 3-foot range — if that — for the next few days.

Through 1 p.m. Wednesday, the ocean temperature ranged from 71.6 degrees at Imperial Beach to 72.4 in San Diego and 72.8 at Carlsbad.