Recently I bought myself and daughters new wetsuits. You might ask, why is that necessary going into the summer in sunny Southern California? Well, if you have been to the beach in the summer in SoCal, you definitely noticed that there is a chill in the water.
In fact, millions of people come to Southern California to enjoy the warm sunny beaches, only to be surprised by the chilly water temps at the beach. This is especially true if you are comparing the ocean temps to places on the East Coast at the same latitude. SoCal ocean water temps peak in the upper 60s and low 70s in August and September. The rest of the year water temps are in the upper 50s and low 60s. Brrrr! Ocean temps are as much as ten degrees cooler compared to locations on the East Coast at the same latitude in summer!
What You Need To Know
- West Coast vs East Coast: Areas with similar latitudes can have different water temps.
- Newport Beach, Calif. August Water Temp: 70 degrees
- Charleston, SC August Water Temp: 86 degrees
There are two general reasons as to why the water temps are much colder on the West Coast compared to the East Coast. The first reason is because of the California cold current that runs along the coast from Canada to Central America. The second reason is upwelling.
There are surface ocean currents in all of the Earth’s oceans. In the northern hemisphere these currents form gyres that flow in a clock-wise direction. In the southern hemisphere oceans, they flow in a counter-clockwise direction. These currents are driven by winds at the Earth’s surface where the atmosphere meets the ocean.
Over the Eastern Pacific, high pressure dominates most of the year. As you probably know, air moves around high pressure in a clockwise direction. This creates a northerly (from the north) wind off the Southern California coast.
Where the air meets the ocean, friction causes “drag” on the surface water which moves the water in the same direction as the wind. So, the end result is that you get a current that transports water from the frigid Gulf of Alaska toward the Equator. Along the way this current passes Southern California. This is called the California cold current. On the East Coast, water moves in the opposite direction, or from the Gulf of Mexico and Caribbean Sea toward Canada and eventually to Northern Europe. Water temps in the Gulf of Mexico peak in the upper 80s and low 90s.
The second reason SoCal has such cool ocean temperatures is because of “upwelling.” Upwelling is the process of bringing deep ocean water to the surface. Upwelling is caused by two factors. The first is related to the aforementioned winds off California. The steady northerly winds move ocean water southward. When the surface water is moved horizontally there is a void where the water used to be. This void is replaced in a vertical direction from the deep ocean along the California coast.
The deep, cold ocean water is “upwelled” to the surface.
Another factor that drives the upwelling process is the Coriolis effect. The Coriolis effect is due to the rotation of the Earth. The Coriolis effect moves objects to the right of their intended path. So, as the winds blow from north to south, the ocean surface water has a tendency to move to the right, or away from the shore. Again, there is a void because of the horizontal movement at the surface where the water originates. This void is filled from the deep oceans along the California coast.
These first days of summer plunge us into yet another iteration of the East versus West debate: Which coast boasts the best beaches? Sure, the Eastern Seaboard, from Cape Cod to Miami, promises white sands and long, sunny days. But there are beaches, and then there are California beaches. To truly appreciate the West, you’ve got to understand the beauty of windswept, overcast sandy shores.
In the summer, ocean air coming off the Pacific turns whole cities gray and cold (hence the often misattributed quote: “The coldest winter I ever spent was a summer in San Francisco”). The Pacific coast has higher waves and stronger winds than the Atlantic. Ocean temperatures here are far colder, too: cold currents stream down from the North Pacific Drift. Meanwhile, back East, the Gulf Stream rolls up from the south to warm things up. In practice, this means that the waters of Miami reach a balmy 86 degrees, while those in San Diego average just 67 degrees during their hottest months. Yet there’s a certain mythological quality to the California seashore—the Beach Boys weren’t singing about Cape Cod in “Surfin’ USA.” In that song alone, they name five places in San Diego to catch waves, and at least seven others along the Golden State’s coastline.
One of the spots where “you’d catch ’em surfin’” is Santa Cruz. I lived there last summer, just a block from the Pacific Ocean, an idyllic setting with a frightening backdrop: the pandemic, still full of unknowns at that point, kept the beaches either closed or overcrowded, and in August, wildfires turned the skies gray and rained ash as we packed our valuables and prepared to be evacuated. Most mornings, though, my roommate and I would wake up before our barista and bartending shifts, wrap ourselves in sweatshirts and beach towels, and brave the misty air to jump in the ocean. We’d hesitate on the water’s edge, feeling it nip at our toes (water temperatures peak at around 60 degrees). We’d run into the surf until our feet couldn’t touch the bottom and dive under the swell. Then we’d come up for air, gasping, and laugh at the absurdity of what felt like an ice bath in the middle of summer.
So, yes, the beaches of California can be cold and rough. You might need a wetsuit. But for those of us who know and love the West, summer is synonymous with big waves, fog, and blue, chilly waters. And there’s no greater part of a beach day than when the fog first burns off and the sun heats up the sand, making a swim in the Pacific a perfect escape.
Now that we’ve determined the superiority of West Coast beaches, drop us a line at newsletters@altaonline.com and let us know your favorite stretch of sand and surf.•