Weather and migraine: what science says

Weather is one of the most commonly reported migraine triggers. In a large clinical survey of people with migraine in the United States, about half named weather changes as something that sets off their attacks [1]. Many describe being able to “feel a storm coming” hours before it arrives.

Research confirms weather sensitivity. When headache diaries were compared with actual weather records, about half of participants showed a measurable link, and they were not always the people who expected one [2]. Sensitivity is individual: a pressure drop can matter a lot to one person and much less to another.

Barometric (air) pressure is the factor most often linked to migraine. It falls when a low-pressure system or a storm approaches and rises again after it passes. A study from Japan found that attacks were more frequent when pressure was slightly below the standard atmospheric level, by about 6–10 hPa [3].

What counts is the level of pressure, how fast it changes and how much it changes over a day. That is why MigraineWatch records the pressure change over 3, 12, 24 and 48 hours, and the largest hourly jump, for every report.

Explanations point to the inner ear's sensitivity to pressure and to effects on blood vessels and the trigeminal nerve system, which plays a central role in migraine.

A study of emergency department visits in Boston found that the risk of a severe headache rose with temperature over the preceding 24 hours and, to a lesser degree, with falling pressure over the preceding days [4]. Other studies point to humidity, strong wind, sudden temperature swings and bright sunlight.

Air pollution and geomagnetic activity are being studied as well. MigraineWatch stores temperature, humidity, dew point, wind, cloud cover, precipitation and UV index with every report, and is adding air quality and geomagnetic data.

Most weather and migraine studies follow tens or a few hundred people in a single city. Reports from many climates at once, matched with weather recorded at the time, show the effect of each weather change far more precisely than diaries filled in from memory.

Migraine is also rarely caused by a single factor. Weather may add up with poor sleep, stress, hormones or a skipped meal and push the brain over its individual threshold.

Each anonymous report is matched with the weather at its place and time. We then use a case-crossover design: the same place one week earlier serves as the control, so every location is compared only with itself. A global grid of pressure readings shows what the weather was like where nobody reported pain.

The clinical questions follow the international ICHD-3 criteria [6], so migraine attacks can be told apart from other headaches. The more reports from different climates, the more reliable the answer.

Keep a headache diary for a few months and note the weather - or simply report each attack here. A pattern you can see is easier to discuss with your doctor.

You cannot change the weather, but on days when a pressure drop is forecast you can lower the rest of the load: keep regular sleep and meals, drink enough water and keep the acute medication agreed with your doctor within reach. If attacks are frequent, ask your doctor about preventive treatment.

Get urgent help for a sudden, explosive “worst-ever” headache; headache with fever and a stiff neck; weakness, numbness, confusion, or trouble speaking or seeing; a headache after a head injury; or a new kind of headache after the age of 50.