Temperatures Set to Soar Next Week After Cool Saturday

Pasadena, buckle up for another dramatic temperature swing.

National Weather Service forecasters said Friday that local temps will sink to a high of just 66 degrees on Saturday before leaping to near 94 by Thursday — a 28-degree increase over six days that could pose health risks for some people.

“NWS ‘heat risk values’ climb for Wednesday and Thursday, trending toward a period of potentially dangerous heat,” forecasters said in their morning briefing.

The cooling trend begins Friday with patchy morning fog and a high near 74 degrees. Light south-southeast winds will become south-southwest at 5 to 10 mph by afternoon as a strong onshore flow pattern becomes established.

Saturday brings the coolest conditions of the forecast period with morning drizzle possible and mostly cloudy skies persisting throughout the day. Overnight lows will dip to around 54 degrees.

NWS meteorologists attribute the weekend cooling to “a persistent marine layer depth” that will reach approximately 2,000 feet by later today and continue deepening to around 4,500 feet by Saturday.

Gusty onshore winds will develop between Saturday and Sunday night, reaching advisory levels across the region. Winds in Pasadena could gust to 15 mph by Sunday afternoon.

Beginning Sunday, an emerging high-pressure system will trigger a steady warming trend pushing temperatures to summer-like levels by midweek. Daytime highs will climb steadily: Sunday (74), Monday (80), Tuesday (88), Wednesday (89) and Thursday (94).

The rapid warm-up is occurring about three weeks earlier than normal, forecasters noted. Some locations outside Pasadena could approach 100 degrees by week’s end.

No formal heat advisories have been issued yet, but residents should prepare for potentially dangerous conditions, especially vulnerable populations unaccustomed to early season heat.

Here is the latest forecast for Pasadena from the National Weather Service as of 4:13 a.m. on Friday, May 16:

Today: Patchy fog before 11:00 a.m. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 74. Light south southeast wind becoming south southwest 5 to 10 mph in the afternoon.

Tonight: Patchy drizzle and fog after 11:00 p.m. Increasing clouds, with a low around 54. South wind 5 to 10 mph.

Saturday: Patchy drizzle before 11:00 a.m. Mostly cloudy, with a high near 66. South southwest wind 5 to 10 mph.

Saturday Night: Mostly cloudy, with a low around 53. South southwest wind 5 to 10 mph.

Sunday: Partly sunny, with a high near 74. Southeast wind 5 to 10 mph becoming south southwest in the afternoon. Winds could gust as high as 15 mph.

Sunday Night: Mostly clear, with a low around 54.

Monday: Sunny, with a high near 80.

Monday Night: Mostly clear, with a low around 58.

Tuesday: Sunny, with a high near 88.

Tuesday Night: Mostly clear, with a low around 63.

Wednesday: Sunny, with a high near 89.

Wednesday Night: Mostly clear, with a low around 64.

Thursday: Sunny, with a high near 94.