A new study confirms what so many who suffer from migraines have long suspected: changes in temperature and barometric pressure can trigger the debilitating headaches.
The study, published in the journal Neurology, also found that air pollution did not seem to trigger migraines.
For the study, researchers looked at 7,054 people who had visited a Boston emergency room over seven years, complaining of intense headaches.
Scientists then compared temperature levels, barometric pressure, humidity and other air pollution or weather factors during the one to three days before the hospital visit.
They found that higher temperatures increased the risk of headache by 7.5 per cent for every five degree Celsius increase in temperature.
Lower barometric air pressure within the two or three days leading to a person's hospital visit also increased the risk of non-migraine headaches.
Air pollution levels had no affect on the risk of headache in the study.
"Air temperature and pressure have been widely cited as a possible trigger for headaches, particularly migraines, but the potential connection hasn't been well-documented," said study author Dr. Kenneth Mukamal, with Beth Israel Deaconess Medical Center and Harvard Medical School in Boston.
Mukamal noted that while his study did not find a link between air pollution and headaches, "other studies have shown that air pollution has possible links to other health problems like heart disease and stroke."
According to Migraine Canada, more than three million Canadians suffer from migraine headaches; the majority of them are women. There appears to be a genetic link, with more than 50 per cent of migraine sufferers having a relative who also suffers from migraine.
The headache is typically one-sided, with moderate to severe pain intensity that can last anywhere from four hours to three days in adults.
