A dramatic warming trend is heading for Pasadena this week, with temperatures forecast to climb more than 20 degrees between Tuesday and Friday, according to National Weather Service forecasters in Oxnard. After a cool and unsettled start to the week, highs are expected to soar into the upper 80s by Thursday and Friday — well above normal for early May.
Current Conditions
Sunday is shaping up as a mild, pleasant day across the Pasadena area. Morning clouds will give way to gradual clearing by midday, with the high reaching about 71 degrees. Winds will remain light and variable through the morning before shifting out of the south at 5 to 10 mph during the afternoon hours. It’s a good day to enjoy the outdoors before conditions shift later in the week.
Near-Term Outlook
Clouds will thicken again Sunday night as low temperatures drop to around 50 degrees. Monday brings another round of overcast skies in the morning before gradually becoming mostly sunny, with a slightly cooler high near 68. Southwest winds will pick up a bit, gusting to 15 mph during the afternoon.
Monday night introduces the week’s only real chance of wet weather. NWS forecasters have placed a 20 percent chance of rain in the forecast for Monday night into Tuesday, with showers most likely after 11 a.m. on Tuesday. Tuesday’s high will hover near 67 degrees under partly sunny skies.
Temperature Trend
The forecast tells a tale of two halves this week. The first half features mild, below-average highs in the upper 60s to low 70s — comfortable and typical of the marine layer’s lingering influence. Then a significant pattern shift takes hold. Wednesday jumps to 78 degrees, Thursday vaults to 87, and by Friday the mercury is expected to top out near 89. Saturday holds steady at 88. That’s a swing of more than 20 degrees in roughly four days — a stark reminder of how quickly Southern California weather can pivot from coastal cool to inland heat.
Precipitation Details
Rain chances remain modest this week, confined to a narrow window. There is a 20 percent chance of showers Monday night, continuing into Tuesday after 11 a.m. No specific rainfall amounts have been forecast by the NWS, and any precipitation that does materialize is expected to be light and scattered. By Tuesday night, skies will clear and dry conditions will dominate for the remainder of the week and into the weekend.
Wind Conditions
Winds will not be a major factor this week, but they will be noticeable at times. Sunday stays calm with light, variable breezes. Monday and Tuesday bring southwest winds of 5 to 10 mph with occasional gusts reaching 15 mph — enough to rustle tree branches but nothing out of the ordinary. As the week progresses and high pressure builds, winds are expected to remain light, allowing afternoon warmth to settle into Pasadena’s foothill neighborhoods without much relief.
Weekend Outlook
The weekend looks hot and sunny. Friday’s high near 89 degrees and Saturday’s 88 degrees will make it feel more like mid-summer than early May. Overnight lows will only dip to around 61, offering limited relief after dark. Residents planning outdoor activities — whether at the Rose Bowl, along the Arroyo Seco trail, or at local parks — should plan for full sun and bring plenty of water. These temperatures are well above Pasadena’s early-May average highs, which typically sit in the mid-70s.
Local Context and Impacts
For Pasadena residents, the week ahead calls for some flexibility. The early-week cool spell is ideal for errands and outdoor exercise, but by Thursday the heat will demand adjustments. Foothill communities along the Angeles National Forest boundary may see temperatures run a few degrees warmer than the city center. Older homes without air conditioning — common in many of Pasadena’s historic neighborhoods — could become uncomfortable by Thursday afternoon. It’s a good time to check that fans and cooling systems are in working order ahead of the summer season.
Gardeners should take note as well. The jump from cool, cloudy conditions to near-90-degree heat can stress young plants and newly installed landscapes. Watering schedules may need a midweek adjustment.
Advisories and Recommendations
While no formal heat advisories have been issued at this time, the NWS may upgrade warnings as the warming trend materializes. Residents are encouraged to stay hydrated, limit strenuous outdoor activity during peak afternoon hours later in the week, and never leave children or pets unattended in vehicles. Those sensitive to heat — including older adults and individuals with chronic health conditions — should take extra precautions beginning Thursday.
Extended Outlook
Beyond Saturday, the warm pattern appears likely to hold into the early part of the following week, though specific details remain uncertain at this range. Residents should monitor updated forecasts from the NWS Los Angeles office for any changes to the outlook.
Looking Ahead
Pasadena’s week begins quietly, with mild temperatures and a brief flirtation with light rain — but the real story is what follows. A substantial warming trend will push temperatures from the upper 60s into the upper 80s by Friday, delivering the hottest stretch of the year so far. Enjoy the early-week cool while it lasts, and start planning now for a warm finish to the week.
Here is the latest National Weather Service forecast for Pasadena as of Sunday, May 3 at 1:47 A.M.
Today: Cloudy through mid morning, then gradual clearing, with a high near 71. Light and variable wind becoming south 5 to 10 mph in the afternoon.
Tonight: Increasing clouds, with a low around 50. South southwest wind 5 to 10 mph becoming light in the evening.
Monday: Cloudy, then gradually becoming mostly sunny, with a high near 68. Light south southwest wind becoming southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.
Monday Night: A 20 percent chance of rain. Mostly cloudy, with a low around 49. Southwest wind 5 to 10 mph becoming light after midnight. Winds could gust as high as 15 mph.
Tuesday: A 20 percent chance of rain after 11am. Partly sunny, with a high near 67. Light southwest wind increasing to 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.
Tuesday Night: Mostly clear, with a low around 50.
Wednesday: Sunny, with a high near 78.
Wednesday Night: Clear, with a low around 56.
Thursday: Sunny, with a high near 87.
Thursday Night: Mostly clear, with a low around 61.
Friday: Sunny, with a high near 89.
Friday Night: Mostly clear, with a low around 61.
Saturday: Sunny, with a high near 88.
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