A National Weather Service heat advisory for the valleys will be in effect until 7 p.m., as high pressure and a weak onshore air flow continue to send temperatures soaring. Forecasters said high temperatures today would be from 85 to 90 along the coastline and over 100 degrees in the far inland valleys and foothills.
On Monday, a high-temperature record of 103 degrees was set in Ramona -- two degrees higher than the prior milestone set two years ago, according to the National Weather Service. In Alpine, a 30-year-old record of 102 degrees was tied.
"Abnormally hot temperatures can be stressful to animals and humans, making it hard for the body to acclimate and remain hydrated,'' according to the weather service. "Without precautions even healthy adults could experience heat stress and illness.''
Many area schools without adequate air conditioning shortened their schedules on Monday to allow students to head to cooler spots, and plan to so again today.
About 120 San Diego Unified School District campuses without full air conditioning will have minimum-day schedules today, including Clairemont, Crawford, Garfield, La Jolla, Madison, Mira Mesa, Mission Bay, Morse and University City high schools. After-school physical activities were canceled at all city schools.
A full list of schools on a reduced schedule today is available on the district's website, sandi.net.
Sweetwater Union High School District officials have implemented a minimum schedule at Mar Vista Academy, Castle Park and Hilltop middle schools, and Chula Vista, Mar Vista and Sweetwater high schools.
The Coronado and National school districts also implemented minimum days today.
More than 100 air-conditioned buildings like libraries and recreation centers will be opened to those trying to beat the heat. County "Cool Zones'' are marked with a light-blue polar-bear logo. A list of county Cool Zones is available at CoolZones.org. or by calling 211.
Forecasters advised area residents planning outdoor activities to schedule them for the cool of the morning or in evening, to take frequent breaks in shady or air-conditioned areas and to know the signs of heat exhaustion and heat stroke. Those planning to be outside were advised to wear light, loose clothing and to drink plenty of water.
Forecasters said that temperatures would cool this evening and Wednesday, though an "influx of monsoonal moisture from the south,'' thanks to Tropical Storm Odile over Baja California, would cause humidity to rise.