Partly cloudy skies for some July Fourth firework shows, warm evenings for desert

SAN DIEGO (FOX 5/KUSI) -- Thousands of people set up shop along San Diego's coastline to celebrate the Fourth of July and to take refuge from inland heat.

This Independence Day is a hot one especially for our mountains and deserts, but the marine layer is acting as a natural air conditioner for the immediate coast where temperatures are in the mid to upper 70s. Beaches started the day with overcast conditions, but eventually those low clouds made way for sunny skies. 

Thursday evening, some of those low clouds will move back inland for beach firework shows such as the Big Bay Boom over the San Diego Bay, but it shouldn't impact viewing of the spectacular.

Inland firework shows won't be impacted by cloud cover but some low clouds could move in in the early morning hours.

Watch out for extreme heat on Friday and Saturday for valleys, mountains and deserts. An Excessive Heat Warning will go into effect the next two days. Temperatures could reach up to 100 degrees in some valley an...