Marine Layer Let Down: How the Marine Layer and Cold Ocean Water Affect Joint Pain (and what to do about it)
San Diego is supposed to be sunny. So why does your knee ache every June? It's not a conspiracy — it's meteorology, and the science is more interesting than you'd expect.
San Diego has a marketing problem. The city sells itself as a paradise of perpetual sunshine. What the tourism brochures fail to mention is "June Gloom": the months-long coastal phenomenon in which a cold marine layer parks itself over the coast each morning like an uninvited houseguest, keeping temperatures in the low 60s and humidity elevated well into the afternoon. For most San Diegans, this is merely annoying. For people with joint pain, it prompts the annual tradition of staring at one's knees and asking them why.
The popular belief that cold and damp weather worsens joint pain has been around long enough that your grandmother probably diagnosed the weather by her hip. As it turns out, she may not have been entirely wrong — though the mechanism is more nuanced than it first appears.
What the research actually says about cold, damp weather and joint pain
The relationship between weather and musculoskeletal pain is real, though researchers have spent considerable energy debating exactly why. A 2024 study published in PMC/NIH examining cold exposure and inflammatory arthritis found that repeated exposure to ambient cold influenced the development and intensity of joint inflammation — suggesting that cold temperatures can act as an environmental trigger for pain amplification in already-sensitized joints.[1]
The prevailing biomechanical explanation involves barometric pressure: as atmospheric pressure drops — which happens during overcast, marine-layer conditions — tissues surrounding joints may expand slightly, increasing pressure on already-inflamed or sensitized structures. Muscles and connective tissues also become stiffer in cooler temperatures, reducing the fluid mechanics that help joints move comfortably. This is not imaginary. It is physics, operating on your musculoskeletal system without asking permission.
"Cold water swimming can influence joint tissue responses, and cold ambient temperature has been shown to affect inflammatory pain development in arthritis models — suggesting temperature as a meaningful environmental variable in joint pain management."[1,2]
Ocean water: cold enough to matter
San Diego's ocean temperature sits between 58–68°F for much of the year — refreshing by most definitions, genuinely cold by physiological ones. For surfers, open-water swimmers, and anyone who has ever waded into the Pacific in March, this is experiential knowledge. For joints, cold water immersion has a complex profile: short-term exposure can reduce acute inflammation and pain (which is why ice packs exist), but prolonged immersion in cold water without adequate warming and movement afterward can increase joint stiffness.
A 2023 feasibility study in PMC/NIH examining exercise programs combined with cold water immersion in patients with rheumatoid arthritis found the combination acceptable and safe, with no aggravation of joint symptoms — but importantly, the protocol involved controlled temperatures and active movement during recovery.[2] The lesson: cold ocean water isn't your enemy, but jumping in cold and sitting still afterward is a less optimal strategy.
Aquatic exercise in the cold months: still worth it
Here's where it gets encouraging. A PubMed-indexed randomized trial found that regular swimming exercise — in temperature-controlled pools rather than the open Pacific — significantly reduced joint pain and stiffness in adults with osteoarthritis over 12 weeks, improving muscle strength and functional capacity with benefits comparable to land-based cycling.[3] The cold is not the problem; cold plus immobility is. Keep moving in the water and the water remains therapeutic.
What to do during June Gloom and beyond
The marine layer burns off. This is a meteorological fact. It typically clears by noon in May and June, and San Diego's inland areas — Balboa Park, Mission Trails, the eastern neighborhoods — warm up considerably faster than the coast. Shifting activity to late morning or early afternoon, warming up more thoroughly before exercise, and not heading to the beach at 7am in a tank top and flip flops in June are all evidence-consistent strategies. Your joints will notice the difference.
Chiropractic care is also particularly valuable during the cooler, damper months, when restricted joint mobility tends to become more symptomatic. Regular spinal adjustments and soft tissue work maintain the joint mobility and neuromuscular function that cold stiffness tends to erode — keeping you moving comfortably through the gloom until the sun comes back, which it will. It always does.
Managing joint pain through San Diego's cool season
Warm up longer before morning exercise during the marine layer months — cold muscles are stiff muscles
Shift outdoor activity to late morning when coastal fog typically burns off
After ocean swimming, warm up actively — don't sit cold and wet on the beach[2]
Pool-based exercise maintains therapeutic benefits year-round without cold-water stiffness risk[3]
Consider a chiropractic check-in at the start of June Gloom season — preventive maintenance beats reactive treatment
References
Kim SH, et al. Effects of repeated exposure to ambient cold on the development of inflammatory pain in a rat model of knee arthritis. Life (Basel). 2024;14(11):1428. PMC / NIH
Peres D, et al. Effects of an exercise program and cold-water immersion recovery in patients with rheumatoid arthritis: a feasibility study. Int J Environ Res Public Health. 2023;20(12):6128. PMC / NIH
Fisken AL, et al. Improved function and reduced pain after swimming and cycling training in patients with osteoarthritis. J Rheumatol. 2015. PubMed