Every person with migraine likely has a unique set of triggers which may include stress, certain foods, alcohol, and other factors. In the same way, some people with migraine are likely sensitive to one weather factor, and others are sensitive to other factors.
An American study found that some people with migraine appear to be sensitive to changes in temperature and humidity. Another American study found that higher temperatures increased the number of patients with migraine who went to the emergency department with headache. Barometric pressure may be another factor. One study looked at whether falling barometric pressure seemed to trigger headaches during a time when a typhoon hit Japan. It found that 75% of people with migraine had migraine attacks associated with the drop in barometric pressure, while only 20% of people with tension-type headache experienced an attack.
The amount of sunshine may also be a factor. In a study from Austria, sunshine for more than 3 hours a day increased the possibility of a migraine, and a Norwegian study found that migraines were more likely during the long summer days in the Arctic.
It does seem clear that different people with migraine may have different weather-related triggers. In a study which involved the Chinook winds, a powerful weather system in Western Canada, it was found that some with migraine were sensitive to the day before the Chinook wind started, at a time when barometric pressure was falling. Others tended to have more migraines the next day when the wind was blowing, although this increased risk was only present if the wind was quite strong. So, even though both groups were Chinook sensitive, there seemed to be 2 different ways in which this weather system could trigger migraines.
Many different weather patterns have been found in different research studies to increase the chances of having a migraine attack in some people, but not in others. Just how these weather patterns cause this is not known.
American Migraine Foundation