SAN DIEGO-- San Diego County is in for a warming trend starting Sunday.
Thursday's cooler than average weather will transition to a brief period of early season heat over the Lower Deserts Sunday and Monday as weak high pressure builds aloft. Highs will range from 109 to 113, which will be 10 degrees above average for early June. Local residents and visitors not yet acclimated to summer heat will be most affected by the heat.
The National Weather Service has placed an excessive heat watch that will go into effect from Sunday morning through Monday evening for Coachella Valley and San Diego County deserts.