A pair of sunglasses with amber lenses lean against a straw sun hat in New York on July 31, 2025. We asked experts if heat, humidity, bright light and changing air pressure may play a role. [Eric Helgas/The New York Times]
Q: I’m always getting headaches during the summer. Why? And what can I do to prevent them?
A: If you’ve noticed more pain between your temples as the warmer months tick by, it may not be all in your head.
Some studies have suggested that hot or humid weather, bright sunlight and summer-related drops in outdoor air pressure can trigger headaches in some people.
Migraine sufferers in particular often report being the most affected, said Dr. Danielle Wilhour, an assistant professor of neurology at the University of Colorado Anschutz Medical Campus.
While there isn’t anything you can do to change the weather itself, the good news is that experts say there are some steps you can take to thwart the throbbing before it starts.
What the research suggests
It can be challenging for scientists to study how the outdoor world influences headache frequency, in part because everyone’s triggers are different, and not everyone is triggered equally. It’s also possible that early migraine symptoms are just associated with, rather than caused by, certain weather changes. As a result, the conclusions of relevant studies have been mixed.
In one study published in 2017, for instance, researchers found that warm and humid conditions in North Carolina were associated with more migraine-related emergency department visits compared with other weather patterns. In another study, published in 2023, researchers in Japan used a smartphone app to track self-reported headaches among nearly 4,400 adults – mostly women. After comparing that data with local weather patterns, they found that headaches were more common in humid weather, but not in the heat.
Other studies, including one published in 2011 that used headache symptom diary entries of nearly 240 migraine patients in Vienna, have found no significant relationship between weather patterns and migraine and headaches.
How weather might lead to pain
Still, it’s plausible that people could be triggered during the summer months, said Dr. Vincent Martin, director of the Headache and Facial Pain Center at the University of Cincinnati Gardner Neuroscience Institute.
In Martin’s own recent research, which was presented at a medical conference in 2024 but has not been fully published or peer-reviewed, he and his colleagues analyzed the daily diary records of 660 migraine patients and found that for every 10-degree temperature increase, there was a 6% increase in the occurrence of any headache.
It’s a bit of a mystery why heat or humidity might increase the risk for headaches and migraine attacks, Martin said.
One theory is that high temperatures could make some temperature-sensing pain nerves more active, inducing more pain, he said. Heat and humidity might also activate the trigeminal nerve in your head, which connects to blood vessels in the brain and is involved in migraine attacks, Wilhour added.
Dehydration may also play a role. “You lose a lot of fluids and electrolytes through sweating,” Martin said, which might change the chemistry around pain neurons, causing them to become more active.
Poor air quality, which is more common with hot weather, has also been linked to headache frequency. And pollutants such as ozone could potentially inflame nerves and trigger a headache, Wilhour said.
Martin also added that bright sunlight may activate the nerve cells in a part of the brain called the occipital cortex, which is particularly sensitive to visual changes in people with migraine, increasing the chance of a headache.
Some research has linked drops in air pressure, which happen during stormy summer weather, with migraine headaches, too. Such atmospheric changes might affect the pressure in the sinuses around the middle ear, which could lead to pain, Wilhour said. It has also been suggested that low air pressure may affect blood vessels in the brain in ways that could spur a migraine attack.
How to reduce your risk
Some experts argue that certain people may mistakenly believe that their headache was caused by the weather, when it was actually caused by something else.
In the early stages of a migraine attack, for instance, some people become sensitive to sunlight and weather changes before the pain starts, said Dr. Christopher Gottschalk, a professor of neurology at the Yale School of Medicine.
It’s also possible that multiple factors, along with the weather, may trigger a headache, Wilhour said.
Staying hydrated may reduce your risk, Martin said. And if you believe you have lost a lot of electrolytes – from excessive sweating, for instance – replenish them with a hydrating drink, such as a sports drink or Pedialyte.
Wearing sunglasses or a wide-brimmed hat can also help reduce the risk that direct sunlight will trigger a headache.
If you frequently have migraine attacks during storms, it’s worth asking a doctor if you should take prescription migraine medication before bad weather starts, such as about an hour before, Wilhour said. People who have migraine attacks more than once or twice a week may benefit from daily medication, she said.
This article originally appeared in The New York Times.