Today's barometric pressure in Portland, a 48-hour pressure chart, and a risk score for weather-triggered migraine and headache, based on pressure drops, humidity, and temperature changes.
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Portland's position between the Pacific and the Cascades creates a channel for persistent low-pressure systems. The city's rainy season from October through May brings extended periods of low barometric pressure that can trigger chronic migraine patterns.
Worst season for migraines: October through March. Portland's extended rainy season brings a parade of Pacific low-pressure systems through the Willamette Valley. Atmospheric rivers from the tropical Pacific produce the most intense pressure events, with sustained low pressure that can last for days.
Common triggers in Portland: persistent Pacific low-pressure troughs, atmospheric river moisture events, Gorge wind pressure differentials. Portland's position between the Coast Range and the Cascades creates a valley that channels weather systems. The Columbia River Gorge acts as a pressure-equalizing corridor between the coast and interior, and Gorge wind events can create rapid localized pressure changes in the eastern metro area.
Typical pressure: Portland averages 1015 hPa at rest, measured at the city's own elevation rather than corrected to sea level, and storm systems can push readings down to 998 hPa. Swings of 6-13 hPa over 24 hours are common during active weather and fall within the range most associated with pressure-triggered migraines.
2026 index: Portland ranks #56 of 100 in our 2026 U.S. Migraine Risk Index, where #1 is the most challenging city for weather-driven migraine.
Can Portland weather trigger migraines?
Yes. Portland experiences 6-13 hPa barometric pressure swings, and research shows pressure drops are one of the most common migraine triggers. The city's specific patterns include persistent Pacific low-pressure troughs, atmospheric river moisture events, Gorge wind pressure differentials.
What time of year are migraines worst in Portland?
In Portland the most barometrically volatile stretch of the year falls in October through March. That is when weather is most likely to play a part, if weather is a trigger for you at all. See when migraine weather season starts across the U.S.
Is there a barometric pressure headache forecast for Portland?
This page works as one. Many people call a headache that arrives with a weather change a barometric pressure headache, and this forecast tracks the pressure drops, humidity and temperature swings behind that idea. The score covers the next 24 hours in Portland and the chart shows the next 48. It is built on migraine research, so treat it as a rough guide for other headaches. A sudden, severe headache needs urgent medical care, whatever the weather.
Your own forecast
This page shows the weather risk for everyone in Portland. The MigrAid app learns yours. It saves the barometric pressure, humidity and temperature with every migraine you log, shows whether Portland's swings really line up with your attacks, and alerts you when conditions match your own trigger history.