For tonight, the marine layer will expand across the coastline and then push inland a few miles towards our lower coastal valleys. I expect most of the fog to develop south of Point Conception, with just some patchy fog north of Santa Barbara. Temperature wise...overnight lows will cool down to the 50s and 60s, helping to provide some relief to our valleys after another hot day.
By the coast on Wednesday...we'll see similar conditions with the marine layer lingering by the beaches. This will mean a mix of sunshine and fog by the coast, with nothing but sunshine on the horizon tomorrow for our valleys. Daytime highs will not be quite as warm on Wednesday, but still there could some lower 100s in our hottest valleys. Coastal temps will range from the 60s for Morro Bay to the 70s in Santa Barbara and Santa Maria to the 80s in Montecito and San Luis Obispo.
High pressure, which has brought the heat to inland areas this week, will break down as we head towards the weekend. This will add up to some cooler and more seasonal temps in our forecast, with also a return to more typical June Gloom weather. With the cool down, coastal temps will mostly warm into the 60s and 70s this weekend, with our valleys comfortably down in the 80s. July Fourth looks questionable by the coast at this point, with a chance of fog and low clouds during the evening hours. The valleys should stay clear.