How to Track Barometric Pressure Migraines

If you want to know how to track barometric pressure migraines, the method is short: log every attack, log the daily pressure reading, log the obvious confounders, then after two or three months count four numbers — not one. The counting is where nearly everyone goes wrong, and it's the difference between finding out whether weather is your trigger and simply confirming what you already believed.

Weather is the most-reported migraine trigger and one of the hardest to demonstrate. That's not a contradiction. It's what happens when a possible cause is highly memorable, completely unavoidable, and impossible to test by intuition.

What the evidence actually says

Weather sensitivity is commonly reported by people with migraine, and a number of studies have found associations between barometric pressure changes and attack frequency. But the literature is genuinely mixed: effects tend to be small on average, some studies find nothing, and — most importantly — the variation between individuals is large. Some people appear clearly weather-sensitive. Many people who are certain they are, turn out not to be.

Two things make this especially hard to judge from memory. The first is that a storm is an extremely memorable event to pin an attack on, so weather-linked attacks are heavily over-remembered relative to the rest. The second is that weather is never alone — pressure drops arrive with humidity changes, temperature swings, disrupted sleep, cancelled plans and travel. Attributing the attack to the pressure specifically is a guess.

None of that means it isn't real for you. It means the only way to know is to count.

Step 1: Get the attack log right first

Weather data is worthless without a reliable attack record to compare it against, and an incomplete attack log is the single most common reason this exercise fails. Before you add anything about weather, make sure you're capturing every attack — including the mild ones you medicate early and mentally discount.

For each attack, the minimum useful record is the date, the rough start time, a pain level, and whether you medicated. Start time matters more here than usual: if you're testing a trigger that changes over hours, "Tuesday" is too coarse to line up against a pressure curve.

Step 2: Record the pressure number daily

You need the reading on non-attack days too — that's the part people skip, and without it the whole exercise collapses. A reading only on days you feel bad tells you nothing.

Where to get it:

• Your phone's weather app. Apple Weather shows barometric pressure in the day's detail view, along with whether it's rising or falling. Most Android weather apps have the equivalent.
• A dedicated barometer app. Many iPhones have a built-in barometric sensor, so these can read local pressure directly rather than from a regional station.
• A home weather station. Overkill for most people, but the most accurate if you're serious.

Record it at a consistent time each day — morning is easiest to sustain. What you're logging is a daily anchor point, plus a note when there's a sharp change. Pressure is reported in hPa or millibars (the same number) or in inches of mercury depending on your region; pick one unit and stay with it.

The variable that matters is almost certainly change, not level. People who live at altitude aren't in permanent migraine. If there's a relationship, it's likely to be with a fall over a day or so, typically ahead of a front.

Step 3: Log the confounders, or you'll blame the wrong thing

This is what turns a diary into an actual test. On the same days, note the handful of things that reliably travel with bad weather and are themselves well-established triggers:

• Sleep — hours, and whether it was disrupted. Storms wake people up.
• Schedule disruption — cancelled plans, travel, a late or skipped meal.
• Alcohol and caffeine — including a missed usual coffee.
• Stress and workload, roughly rated.
• Menstrual cycle day, if relevant — hormonal patterns can easily masquerade as weather patterns over a short window.

If a pressure-drop day is also a bad-sleep day, and you only logged the pressure, you've built a case for the wrong trigger.

Step 4: Count all four boxes

Here's the step that matters. After eight to twelve weeks, sort your days into four groups — not two.

	Pressure drop	No pressure drop
Attack	A — the days you remember	B — attacks with calm weather
No attack	C — storms with no attack	D — uneventful days

Intuition only ever counts box A. Box A is why people are certain about weather: every entry in it is vivid and confirms the story. Boxes B and C are the ones that decide the answer.

• Box C large — plenty of pressure drops passed without an attack — means pressure alone isn't sufficient. It might still matter in combination, but it isn't the driver.
• Box B large — plenty of attacks on calm days — means pressure isn't necessary either. Something else is doing most of the work.
• A high relative to C, and B small is the pattern that actually supports weather sensitivity.

Compare rates, not raw counts: what fraction of pressure-drop days produced an attack, versus what fraction of other days did. If those two percentages are close, weather isn't your trigger, however many storms you can remember.

Step 5: Decide what to do with the answer

Both outcomes are useful, which is unusual for trigger hunting.

If it looks real: you can't avoid weather, so the payoff is in preparation and stacking. Weather often appears to matter most when it lands on top of something else, so on forecast pressure-drop days you protect what you can control — sleep, meals, hydration, alcohol, and how much you schedule. If you take acute or preventive medication, the timing of it around those days is worth raising with your clinician, who's the right person to make that call.

If it doesn't: that's arguably the better result. You stop bracing for every forecast, stop attributing attacks to something unchangeable, and redirect attention to triggers you can actually act on. Ruling a trigger out is one of the most valuable things a diary does, and almost no one does it deliberately.

Making this sustainable

The failure mode of this whole exercise is abandonment. It needs daily entries on ordinary days for three months, which is far harder than logging attacks — and it has to survive the days when you're mid-attack and can't face a form.

That's the problem MigrainePal (ours) is built around: when an attack starts you tap once, the app opens an episode with the start time, and you put the phone face-down. Pain level, aura, medication and trigger notes get added later, when your head clears. Weather is one of the triggers you can log alongside sleep, stress, food, screens and hormones, and the headache calendar shows the month visually, so clusters and weather-linked runs surface as shapes rather than as a wall of text.

One honest limitation: MigrainePal doesn't pull barometric data automatically — you log the reading yourself as a trigger note, the same way you'd log sleep. If you want an app to do the statistical correlation work for you instead, N1-Headache is built specifically for that, and we placed it and the other options in the best migraine tracker apps. There's also a longer head-to-head with the category giant in MigrainePal vs Migraine Buddy.

The bottom line

Tracking barometric pressure migraines properly takes three months and about twenty seconds a day, and it only works if you log the boring days as carefully as the bad ones. Record every attack, record the daily pressure, record the confounders that travel with storms, then count all four boxes rather than the one you remember. You'll come out with either a real trigger you can plan around, or one fewer thing to blame — and both are worth having.

Frequently asked questions

Can barometric pressure changes really trigger migraines?

Weather is one of the most commonly self-reported migraine triggers, and studies have found associations between pressure changes and attack frequency in some groups. But the research is genuinely mixed, the average effects are small, and results vary a lot between individuals — some people show a clear relationship and many show none at all. The honest position is that weather sensitivity is real for some people with migraine and over-attributed by many others, which is exactly why testing it against your own logged data is more useful than reading about population averages.

How much does barometric pressure need to drop to trigger a migraine?

There is no established threshold, and be sceptical of any source that gives you a precise number as though it applied to everyone. What people who track this tend to find is that the rate of change matters more than the absolute reading — a fall over the course of a day, typically ahead of a storm front, rather than simply living somewhere with low pressure. Your own threshold, if you have one, is something only your own data can show. Log the daily reading alongside your attacks and look at what the drops actually coincide with.

How long should I track weather before I know if it's a trigger?

Plan on eight to twelve weeks minimum, and longer if your attacks are infrequent. The reason is arithmetic rather than patience: to say anything about a pattern you need enough attacks to compare against enough non-attack days, and with three or four attacks a month a shorter window gives you numbers that noise can easily explain. If you get very few attacks, extend the window rather than drawing a conclusion early — a false answer here is worse than no answer, because it sends you chasing the wrong trigger.

What can I do about weather-triggered migraines?

You cannot change the weather, so the value of confirming it is in timing and in trigger stacking rather than avoidance. Knowing a pressure drop is coming lets you protect the things you can control on those days — sleep, hydration, meals, alcohol, schedule load — because weather often seems to matter most when it lands on top of another stressor. It also informs conversations about acute or preventive treatment timing with your clinician, which is where those decisions belong. And if the count shows no relationship, that is a real result too: you stop bracing for storms and start looking at the triggers that are actually driving your attacks.

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Related: The Best Migraine Tracker Apps and MigrainePal vs Migraine Buddy. Questions? Email us.