July brings a subtle dance of temperatures and clouds to the southern California skies, as forecasted by the National Weather Service in San Diego. A weak upper-level low-pressure system strolling through central and southern California is ushering in cooler air and a deepening marine layer. According to NWS San Diego, this system will result in a 5-degree drop in high temperatures through Thursday, with the cooling trend being most noticeable inland, where the heat usually bakes the valleys.
Inland areas like the Inland Empire, often scorching during this time of year, can expect daytime highs hovering in the 80s and low 90s on Thursday - a welcome reprieve from the usual onslaught of summer heat. Meanwhile, the coastal regions are set to experience milder temperatures around 70, while the lower deserts brace for the mercury to hit between 104 and 108 degrees. The marine layer, a blanket of moist air, will deepen, reaching 2000 to 2500 feet and pushing night and morning low clouds further into the valleys, providing a few moments of respite during the early hours of the day.
However, this cooling effect is a temporary guest; as the NWS San Diego predicts, a slow warming trend will follow from Friday into early next week. The marine layer will thin out again, sparing the valleys from the reach of coastal clouds. For those making weekend plans, expect temperatures for the coast and valleys to warm up to about average by Sunday, while the lower deserts could see temperatures sizzle to around 10 degrees above the norm for early July, with highs potentially cresting between 106 and 110 degrees.
For beachgoers, there's more than heat to consider this weekend. A south swell is rising, with expected 3-5 feet waves, and even 6 feet sets at south-facing shores. "Building southerly swell (190 degrees) of 3 feet at 14-15 seconds will generate elevated surf of 3-5 ft with sets to 6 ft along southerly facing beaches," NWS San Diego states, warning of strong rip and longshore currents. Swimmers and surfers should take note of these conditions and exercise caution, especially on Friday and Saturday before the swell ebbs on Sunday.
Overall, Southern Californians are in for a brief climate cooldown before the region settles back into its summer sizzle. While those in the valleys get a temporary break from the peak summer heat, the coast prepares for high surf and riptides, reminding us of the incessant push and pull between land and sea.
