South Pasadena will stay in the upper 90s through the weekend with overnight lows in the low 70s, according to the National Weather Service Los Angeles/Oxnard office. A second and stronger round of heat is expected to begin Tuesday, August 25, with forecast highs of 100 to 103 degrees Tuesday through Friday.
As of Saturday morning, no heat advisory or warning is in effect for the San Gabriel Valley or any land zone in Los Angeles County. The NWS heat advisory that covered the San Gabriel Valley Tuesday, August 18 through Thursday, August 20 has expired. Forecasters say the midweek heat has a 40 to 60 percent chance of reaching advisory levels again, and possibly warning levels inland.
Current Conditions
At 12:25 p.m. Saturday, the NWS downtown Los Angeles station reported 93 degrees, 38 percent humidity, a dew point of 64 degrees and a heat index of 95 degrees, with a light southeast wind at 4 mph.
Day By Day Forecast
The following is the NWS point forecast for the South Pasadena and Alhambra area (elevation 410 feet), last updated 11:57 a.m. Saturday, August 22. Temperatures are in degrees Fahrenheit.
Saturday, August 22: Sunny and hot. High near 98. Southwest wind 5 to 10 mph. Overnight clear, low around 71.
Sunday, August 23: Sunny and hot. High near 99. Light south-southwest wind becoming southwest 5 to 10 mph in the afternoon. Overnight mostly clear, low around 72.
Monday, August 24: Sunny and hot. High near 98. Light and variable wind becoming southwest 5 to 10 mph in the afternoon. Overnight mostly clear, low around 72.
Tuesday, August 25: Sunny and hot. High near 100. Overnight mostly clear, low around 73.
Wednesday, August 26: Sunny and hot. High near 103. Overnight mostly clear, low around 74.
Thursday, August 27: Sunny and hot. High near 103. Overnight partly cloudy, low around 73.
Friday, August 28: Mostly sunny and hot. High near 102.
Saturday, August 29 and Sunday, August 30: Beyond the current NWS seven-day point forecast. The NWS forecast discussion states ensemble guidance is trending toward at least three days of hot conditions beginning Tuesday. The South Pasadenan will update this outlook as the forecast extends.
What The Forecasters Are Saying
The NWS Area Forecast Discussion issued at 5:48 a.m. Saturday describes minimal change through the weekend, with above normal temperatures. The combination of hot daytime highs, warm overnight lows and some monsoonal moisture at mid to upper levels will continue to feel uncomfortably warm. Some interior valley locations will run about 10 degrees above normal, but forecasters said the hottest areas were not widespread enough Saturday to warrant a heat advisory. Caution is still advised for anyone working or recreating outdoors during the day.
High resolution guidance does not show significant shower activity over the area for the next few days, though forecasters said a stray shower cannot be ruled out in favorable interior locations.
For Tuesday onward, the discussion states high pressure is expected to build back into California while pressure gradients from the north and east weaken. With temperatures already on the verge of advisory and warning thresholds, forecasters give the next burst of heat at least a 40 to 60 percent chance of reaching at least heat advisory levels and possibly warning levels, particularly for inland areas. The more likely scenario, per the discussion, is a slightly weaker offshore gradient that keeps temperatures hot but a few degrees cooler than the worst case. Warm ocean temperatures are expected to continue limiting overnight cooling.
LA County Advisories
Los Angeles County Department of Public Health: The most recent county heat advisory release, dated August 17, covered Tuesday, August 18 through Thursday, August 20 for the San Fernando, San Gabriel and Santa Clarita valleys and the Western San Gabriel Mountains. That period has ended. No new county heat release had been posted as of Saturday. Public Health directs residents to the NWS HeatRisk map at wrh.noaa.gov/wrh/heatrisk for neighborhood-level risk.
City of South Pasadena: The city’s standing policy activates two cooling centers when outdoor temperatures reach or exceed 96 degrees. Saturday’s forecast high of 98 and every forecast high through Friday meet that threshold. The South Pasadenan has not confirmed a separate city announcement for this heat period as of publication.
Cooling Centers
South Pasadena Senior Center, 1102 Oxley Street. Monday through Friday, 8 a.m. to 5 p.m.
South Pasadena Public Library, 1100 Oxley Street. Monday 10 a.m. to 6 p.m.; Tuesday through Thursday 10 a.m. to 8 p.m.; Friday and Saturday 10 a.m. to 6 p.m.; Sunday 1 p.m. to 5 p.m.
Both locations offer air conditioning, public Wi-Fi, computer access and free reading material during regular business hours. Service animals are permitted; pets are not. Additional county cooling centers can be found by calling 211 or at ready.lacounty.gov/heat.
Heat Safety
Los Angeles County Public Health advises residents to drink water throughout the day without waiting to feel thirsty, avoid outdoor activity during the hottest hours, wear lightweight and light colored clothing and a hat, and check on older adults, young children, pregnant people, outdoor workers, athletes, people with chronic medical conditions and anyone who lives alone. Never leave children or pets in a parked vehicle.
Call 911 for signs of heat stroke, including a body temperature of 103 degrees or higher, confusion, dizziness, vomiting, a fast and strong pulse, or hot, red, dry or damp skin.
