Many people with arthritis believe that the weather affects their symptoms, but is there scientific evidence that warmer temperatures can actually relieve psoriatic arthritis pain?

A study published in May 2007 in the American Journal of Medicine found that patients with arthritis reported an increase in knee pain for every 10 degrees that the temperature dropped. While the researchers admitted that a consistent relationship between joint pain and the weather was “strikingly difficult to prove,” the study’s results support the idea that changes in temperature and barometric pressure could have an impact on arthritis symptoms.

Similarly, a study published in April 2014 in the Journal of Pain found that changes in weather variables like relative humidity can affect arthritis-related hip pain. The Arthritis Foundation even provides an online tool to predict joint pain based on local weather forecasts.

Still, when it comes to psoriatic arthritis and the weather, Steven Vlad, MD, PhD, assistant professor at Tufts University School of Medicine and rheumatologist at Tufts Medical Center in Boston, is skeptical.

Weather and Your Immune System

“Psoriatic arthritis is a disease of the immune system,” Dr. Vlad says. “There is no reason for us to expect that weather or seasonal changes will affect the course of the disease or the symptoms of the disease, because there's no evidence that weather influences the immune system to any significant extent.”

While Vlad questions the weather’s impact on psoriatic arthritis, he does acknowledge that sunnier conditions can spell relief for people with psoriasis, a related autoimmune disease affecting the skin. The warmer weather typically brings more humidity, which helps moisturize the uncomfortable and itchy scales of psoriasis. “Sun can help the symptoms of psoriasis, and many people report improvements in their skin,” he adds. “But it’s not clear that it helps with the symptoms of arthritis.”

What Studies Show

A Norwegian study published in August 2002 in the Journal of the American Academy of Dermatology found that patients who underwent climate therapy, consisting of warmer temperatures and increased sun exposure, reported an improvement in psoriasis symptoms but not a significant decrease in psoriatic arthritis pain.

study published in August 2012 in the journal Annals of the Rheumatic Diseases also concluded that seasonal changes between summer and winter did not affect disease activity in people with psoriatic arthritis.

Warm-Weather Benefits

Despite the lack of evidence that there’s a direct connection between weather conditions and psoriatic arthritis, Rosalyn George, MD, dermatologist with the Wilmington Dermatology Center in North Carolina, believes that warmer weather can still benefit patients.

“There have actually been no formal studies that show warmer weather helps psoriatic arthritis,” says Dr. George. “But I never discount that better weather can encourage people to be more active, which can help relieve some of the symptoms.”

According to the National Psoriasis Foundation, physical activity can help reduce the inflammation and pain of psoriatic arthritis. Warm-water exercise, in particular, can help loosen stiff joints and relax sore muscles.

“In general, activity will help the symptoms of arthritis,” Vlad says. “And people with some level of psoriatic arthritis will often feel better when they are active.”