Rheumatoid arthritis (RA) is a progressive form of inflammatory arthritis wherein an overactive immune system attacks the lining of the joints. This causes pain, stiffness, and swelling in the joints.

Some people with RA notice that their symptoms get worse during certain times of the year. Seasonal weather changes may trigger RA flares during the winter, spring, or summer months.

Large, high quality studies into the effects of weather on RA are sparse. However, there is some evidence to suggest that seasonal weather changes may impact a person’s RA symptoms.

People with RA experience what are known as flares. During a flare, a person will experience a period of more intense RA symptoms, including:

  • fever
  • fatigue
  • joint pain, swelling, or stiffness

Flares are followed by remissions, when symptoms improve.

According to the Arthritis Foundation, doctors and people with RA often disagree about what a flare is.

A person with the condition may define a flare as a period of time when the symptoms increase and possibly cause them to miss social or work engagements. Doctors often define flares as periods of more joint involvement, a significant change in laboratory work, or both.

Flares sometimes have no known cause. Other times, they can be linked to triggers such as:

  • food, though there is no evidence to back up any specific food triggers of RA
  • infections or other medical issues
  • a person’s mood or stress level
  • increased physical activity
  • weather

Some scientific evidence suggests that weather or seasonal changes may impact a person’s RA symptoms.

Experts do not understand exactly why this connection may exist. Some theories include the following:

  • Changes in barometric pressure during a cold front cause the tendons, muscles, bones, and scar tissues to contract and expand. This causes pain in the tissues that arthritis affects.
  • Low temperatures may increase the thickness of joint fluids so that the joints become stiffer and harder to move.
  • People may be less active in colder weather, which worsens symptoms.
  • Extreme weather dampens a person’s mood, which, in turn, worsens RA symptoms.

The sections below look at what the research has to say.

Seasons and flares

A 2019 study of more than 12,000 people with RA concluded that symptom flares in the small joints of the hands and feet occurred most often in the spring, then in the winter. Seasonal changes seem to have less of an impact on the larger joints.

In a smaller 2020 study, researchers found that extreme temperatures in the summer and winter significantly impacted RA symptoms. Other autoimmune conditions, such as Sjögren’s, also seemed to flare during extreme weather in the summer and winter.

Weather and flares

Some people report that pain and arthritis symptoms worsen during periods of cold, rain, and low atmospheric pressure. Others say that flares tend to occur when it is humid or hot outside. For now, there is no scientific consensus on how weather affects RA flares.

In a 2019 study, researchers gave 2,658 people a smartphone app to regularly track their pain levels, the weather, their moods, and their physical activity levels.

Over the course of 6 months, most people reported a modest increase in pain or discomfort when the weather was humid or windy or when atmospheric pressure was low. These findings applied even when the researchers took the person’s moods and physical activity levels into account.

The participants included people with osteoarthritis and other medical conditions. The findings may not apply universally to all people with RA.

The researchers also note that the findings could be biased by the participants’ prior beliefs, as people who join this type of study may already believe that there is an association between their symptoms and the weather.

In a small 2013 study, researchers looked at the effects of temperature on symptoms in mostly middle aged people visiting an emergency room for RA. They found that lower temperatures tended to be linked to RA flares in people between the ages of 50 and 65 years.

The researchers found no associations with humidity or atmospheric pressure. They speculate that this could be because they conducted the study in Madrid, Spain, which has a generally dry and stable climate.

They could not explain why there was no significant link between RA symptoms and weather in younger or older adults. They speculate that cold weather could cause stiffness in the muscles around the joints, which could make arthritis symptoms worse.

Studies that have not found a link

Not all researchers agree that certain weather or seasons cause or are linked to RA pain or stiffness.

It is difficult to design a study that takes into account the many potential factors that could impact a person’s RA symptoms, from the foods they eat to their stress or activity levels. It could be that temperature extremes affect a person’s mood and ability to exercise, which, in turn, impact RA symptoms.

In addition, study participants may already believe that there is a link between certain weather patterns and RA flares. This could influence how they self-report their symptoms and, by extension, the overall results.

A 2012 review of several hundred studies found only 19 that were of high enough quality for inclusion. The authors conclude that the research does not conclusively link weather and RA symptoms and that additional studies are necessary to objectively measure RA symptoms.

That is not to say that weather does not impact RA symptoms. Other researchers have found a correlation. However, because high quality and bias-free studies are difficult to design, experts may never come to a definitive conclusion.

Seasonal or weather-related RA flares are difficult to avoid. There are some strategies to ease RA symptoms, however.

The following steps may help if cold weather seems to be linked to an RA flare:

  • Dress for the weather. Some research suggests that if colder weather worsens arthritis symptoms, wearing warmer clothes that are designed to retain heat may help. Most heat is lost from the extremities, so it is important to wear a scarf, hat, boots, and gloves.
  • Wear thermal compression gloves. These release heat and compress the fingers to reduce swelling.
  • Maintain exercise routines. People tend to move less in winter, but staying physically active is critical to managing RA. Cardiovascular exercises, strength training, and stretching can help:
    • ease pain and stiffness
    • improve range of motion
    • boost energy levels and mood
  • Talk with a doctor about taking a vitamin D supplement. People tend to be deficient in vitamin D during winter. Lower vitamin D levels have been linked to more severe RA and sensitivity to pain.
  • Use heat therapy. Warm compresses, showers, and baths can help relax the muscles and may improve pain tolerance.

If weather or seasonal changes affect a person’s RA, they should talk with a doctor about how to safely manage their symptoms. The doctor may recommend an increase in medications or changes in therapy.

Researchers still do not agree on the exact effect that weather and seasons have on RA.

This does not mean that people do not experience flares in their RA symptoms during certain seasons or weather conditions, such as rain or cold temperatures.

Wearing warmer clothes and staying active during the winter months may help. A person should also work with a doctor to adjust their treatment plan as necessary to manage seasonal flares.

Read this article in Spanish.