SAN DIEGO — San Diegans should brace for another heat wave as a strong high pressure system will last until at least midweek.

An excessive heat warning is in effect for the coast, valleys, mountains and deserts until Wednesday at 8 p.m. 

Highs at the coast could reach into the 90s. Inland and mountain areas are expected to see triple-digit heat. The deserts could reach highs up to 112. 

Even the low temperatures at night will be scorching.

  • Lows at the coast and inland will be in the mid 70s to 80s;
  • Lows in the mountains will be around 65 to 75 degrees;
  • Lows in the deserts will be in the mid 80s to low 90s.

Isolated thunderstorms may also pop up west of the mountains and drift westward toward the coast Sunday afternoon and then again on Labor Day (mainly north of the county).

Temperatures will be hot for Labor Day ahead.

The coast is expected to hit 90 degrees for the high. Inland areas are expected to hit 102 degrees. The mountains are expected to be 92 degrees for Labor Day with gusts up to 30 miles an hour. The high in the deserts is expected to hit 112 degrees with gusts up to 20 miles an hour.

Temperatures will start to gradually cool down after Wednesday.

Then, a tropical storm system approaching next weekend could bring more rain.