What Kind of Arthritis Hurts When It Rains?

Nearly every type of arthritis can flare when rain moves in, though the mechanism differs depending on the condition. Osteoarthritis, rheumatoid arthritis, psoriatic arthritis, and even fibromyalgia-related joint pain have all been linked to the damp, low-pressure weather systems that accompany rain. The specific weather variable that seems to matter most varies by condition: barometric pressure drops appear to affect osteoarthritis more consistently, while humidity hits rheumatoid arthritis patients harder. Still, the relationship between weather and joint pain is messier than the folklore suggests, and at least one form of arthritis, gout, behaves in almost the opposite direction.

Most People With Arthritis Are Convinced Weather Matters

Before diving into the science, it helps to know that this is not some fringe belief. In a large European study spanning six countries, about two-thirds of older adults with osteoarthritis said the weather affected their pain.¹ A separate study of knee osteoarthritis patients found that close to 60% perceived the same connection.² Among rheumatoid arthritis patients, similar majorities report weather sensitivity, even though studies formally testing that link have produced mixed results.³ The gap between patient experience and what the research can consistently demonstrate is one of the most frustrating features of this entire topic.

Osteoarthritis and Barometric Pressure

Osteoarthritis, the wear-and-tear form of the disease, is by far the most studied type when it comes to weather. A systematic review and meta-analysis that pooled data from multiple studies found that barometric pressure was positively related to osteoarthritis pain, and lower temperatures were also associated with increased pain.⁴ In practical terms, that means the falling barometric pressure that precedes a rainstorm, combined with the cooler temperatures that often come with it, is exactly the combination most likely to make an osteoarthritic knee or hip ache.

One clinical study tracked osteoarthritis patients daily and found consistent associations between pressure changes and pain severity, as well as between lower ambient temperature and worse pain.⁵ But the picture is not unanimous. A case-crossover study of knee osteoarthritis patients found no clear association between temperature, humidity, air pressure, or precipitation and the risk of a pain flare.⁶ That null result is a useful reminder: the average effect across a group of patients can be real but small, and any individual patient may not follow the pattern at all.

Why would barometric pressure matter to a joint with worn-down cartilage? The leading explanation involves tissue expansion. When air pressure drops, tissues in and around the joint expand slightly. In a healthy joint, this change is trivial. In an osteoarthritic joint where cartilage is eroded, the bones are closer together, and the surrounding tissues are already inflamed, even a tiny expansion can press on nerve endings that are already sensitized. Cold temperatures add to the problem by thickening the synovial fluid inside the joint, making it stiffer and less shock-absorbent.⁷ A rainy day often delivers both of those factors at once.

Rheumatoid Arthritis and Humidity

Rheumatoid arthritis is a different beast. It is an autoimmune condition where the body’s immune system attacks the joint lining, causing inflammation, swelling, and pain that can affect joints symmetrically on both sides of the body. For RA patients, the weather variable that shows up most consistently in the research is humidity rather than barometric pressure.

A study tracking RA disease activity found that increased humidity was associated with higher disease activity scores, while sunnier and less humid conditions were linked to significantly lower scores.⁸ Another study found that tender joint counts in RA patients correlated with humidity in winter, and with precipitation in summer.⁹ Rain, of course, comes with high humidity, so the two are intertwined in practice.

One intriguing finding is that weather’s influence on joint pain may not depend much on which rheumatic disease you have. A prospective time-series analysis that followed patients with different chronic rheumatic conditions found that the influence of environmental factors on pain was independent of the type of disease, raising the possibility that weather acts on pain perception pathways shared by many conditions rather than on the specific disease mechanism in each one.¹⁰

Gout Runs in the Opposite Direction

If you have gout, rain is not the problem. Hot, dry weather is. Gout is caused by uric acid crystals forming in a joint, and the risk of a flare appears to rise when temperatures climb and humidity drops. A large case-crossover study found that higher temperatures over the preceding 48 hours were associated with roughly 40% higher risk of a gout attack compared with moderate temperatures. The combination of high temperature and low humidity carried about double the risk.¹¹

The suspected reason is dehydration. Heat and low humidity cause more fluid loss through sweat, which concentrates uric acid in the blood and makes crystallization in the joints more likely. A Korean study also found that rapid diurnal temperature swings and sudden humidity changes, both common in spring, were associated with gout seasonality.¹² So while gout sufferers are weather-sensitive, their pattern is almost the mirror image of what people with osteoarthritis or RA experience. Rain might actually be neutral or even protective for gout, since it typically brings cooler, more humid air.

Fibromyalgia and Temperature Sensitivity

Fibromyalgia is not a joint disease in the same way as osteoarthritis or RA, but people with fibromyalgia frequently report joint-area pain that worsens with weather changes, and they often receive an initial misdiagnosis of arthritis before the fibromyalgia is identified. The relationship between fibromyalgia pain and weather is driven more by temperature than by barometric pressure or humidity. Patients with fibromyalgia report pain flares with temperature changes and have lower thresholds for both heat- and cold-induced pain compared with healthy people.¹³

A systematic review found consistent evidence that fibromyalgia patients have abnormally sensitized temperature-sensing systems, and that a subgroup experiences extreme temperature sensitivity during winter that can be genuinely disabling.¹⁴ The cold, damp conditions of a rainy day are exactly the type of environment that can trigger these symptoms. What remains unclear is why only some fibromyalgia patients are severely weather-sensitive while others are not.

What Humidity Does to Joints at a Biological Level

The humidity that comes with rain deserves its own discussion because its effects go beyond simple discomfort. Animal studies have shown that sustained high humidity can cause measurable cartilage damage. In rats, high-humidity conditions led to visible joint swelling, reduced cartilage staining, and fewer healthy cartilage cells, and when the rats already had an arthritis model, high humidity made the joint deformation and cartilage loss significantly worse.¹⁵

The mechanism appears to involve the gut. High humidity has been shown to disrupt gut bacteria in ways that promote the growth of inflammation-triggering microbes. These changes can increase the production of pro-inflammatory molecules that travel through the bloodstream and reach the joints, where they activate inflammatory pathways and weaken antioxidant defenses.¹⁶ This is still largely preclinical work, and translating rat findings to human patients requires caution. But it offers a plausible biological route by which chronic exposure to damp climates could genuinely worsen arthritis rather than just make it feel worse.

It is also worth noting that the relationship between humidity and arthritis is not a simple straight line. The same study that identified harmful effects from high humidity also found problems at low humidity. Extremely dry air can impair synovial fluid function. The joints appear to prefer moderate humidity, with both extremes causing trouble through different pathways.¹⁶

Low Pressure and the Nervous System

The barometric-pressure explanation is not limited to tissue expansion. Animal experiments have shown that drops in barometric pressure can directly amplify pain signaling through the nervous system. In one study, lowering barometric pressure worsened pain-related behaviors in rats with nerve injuries, and the effect appeared to involve the sympathetic nervous system, the same system responsible for the body’s fight-or-flight response.¹⁷ A similar experiment in guinea pigs confirmed that pressure drops within the range of normal weather patterns can intensify pain, and found that the effect increased when the drop was larger.¹⁸

These findings matter because they suggest the rain-pain connection is not unique to arthritis. Any condition involving sensitized nerves, whether from joint damage, a prior surgery, or a nerve injury, could theoretically flare when a storm system moves in. This aligns with patient reports: people with old fracture sites, surgical scars, and non-arthritic joint injuries often say they can “feel the weather coming” just as arthritis patients do. A study of patients recovering from orthopedic trauma found that while postoperative pain was initially driven by the surgery itself, over time, barometric pressure, temperature, and humidity began to influence their pain levels.¹⁹

The Confirmation Bias Question

No honest article on this topic can skip the psychology. One well-known study from the 1990s tracked 18 arthritis patients for over a year and found no statistically significant association between their pain and the weather conditions each patient had named as triggers. The same researchers showed that college students tend to perceive patterns between completely random, unrelated sequences of numbers, suggesting that the human brain is wired to find connections that are not there.²⁰

A more recent study found that while weather factors could account for at most about 17% of the variability in arthritis symptoms, depression scores were a significant contributor. And the patients’ belief in a weather-arthritis link was stronger than the actual statistical relationship.²¹ This does not mean the connection is imaginary. What it means is that the effect, where it exists, is modest and easily overwhelmed by other factors like mood, sleep, activity level, and medication timing. People tend to remember the days when rain and pain coincided and forget the rainy days when they felt fine, or the dry days when their joints ached.

Researchers in this area have not “debunked” the weather-pain link so much as shown that it is smaller and more variable than most patients believe. The meta-analyses that pool many patients together do find statistically significant correlations with barometric pressure, temperature, and humidity. The correlations are just modest enough that they can disappear in any individual patient’s daily experience, only to show up when you aggregate thousands of diary entries.

Why Studies Disagree So Often

One reason this research field is so frustrating is that studies done in different climates are testing different things. A review of the literature noted that studies conducted in tropical or subtropical locations, where day-to-day weather does not vary much, cannot really test whether cold or pressure drops affect pain. Meanwhile, studies in colder, more variable climates have more weather extremes to work with but also more confounding factors, since people in cold climates may be less active in winter, which itself worsens joint stiffness.²² A narrative review similarly noted that warmer, stable conditions tend to favor mobility, while colder and more variable conditions link to increased pain and stiffness, but that precipitation, sunlight, and wind show minimal or inconsistent effects.²³

Another complication: most weather studies use regional weather station data rather than measuring what the patient actually experienced. If you spent your rainy day inside a heated office, the outdoor temperature drop may be irrelevant to your pain. And if the study uses daily average weather readings, it misses the barometric pressure swing that happened over two hours in the morning, precisely the kind of rapid change patients often blame for their flares.

Practical Takeaways for Different Types of Arthritis

If you have osteoarthritis, the evidence points to falling barometric pressure and dropping temperatures as the most consistent weather triggers. A warm layer over the joint, staying active indoors when the weather turns, and preemptive use of whatever pain management strategy you already rely on are the standard practical responses. Waiting until the pain arrives means the inflammation and stiffness have already set in.

If you have rheumatoid arthritis, humidity appears to be the more relevant variable. Dehumidifiers at home, climate-controlled exercise environments, and keeping track of your personal pattern with a simple pain diary can help you and your rheumatologist identify whether weather is genuinely a factor for you or whether other triggers are more important.

If you have gout, your weather concerns are reversed. Hot, dry conditions are your risk factor, probably because of dehydration. Staying well-hydrated during heat waves and monitoring your fluid intake during spring weather swings, when temperatures can shift dramatically within a single day, is more relevant than worrying about rain.

If you have fibromyalgia, temperature drops are the primary weather-related trigger. Because the sensitization is in the nervous system rather than in joint cartilage, the strategies that help are those that keep your body temperature stable: layered clothing, warm baths, heated blankets, and avoiding prolonged exposure to cold, wet environments.

When People Move to Warmer Climates and Nothing Changes

One of the more revealing facts about weather-sensitive arthritis is what happens when people relocate to escape it. Rheumatologists have observed for decades that patients who move from, say, the rainy Pacific Northwest to sunny Arizona often report initial relief followed by a return of weather-triggered pain within a year or two. The body appears to recalibrate. Once you adapt to the new baseline climate, it is the changes relative to that baseline, not the absolute temperature or humidity, that your nervous system responds to. A pressure drop in Phoenix is still a pressure drop, even if the starting point is higher and drier than Seattle.

This is consistent with the animal research showing that it is pressure fluctuations, not absolute pressure levels, that worsen pain signaling. It also explains why the research cannot point to a single “safe” climate for arthritis. Adverse weather was associated with reduced outdoor activity and lower participation in rehabilitation, regardless of the specific climate being studied.²³ Moving somewhere warm may help you stay more active on average, and that regular activity may do more for your joints than the weather itself. But if you are moving specifically to escape rainy-day pain flares, you may find that the flares follow you in a milder but still recognizable form.