From evidence to your daily score.
Each trigger is a module built from the migraine-research literature. The score blends them with confidence weights, then sharpens around your personal patterns as you log.
The evidence base
Eleven triggers, each backed by published research on migraine prevalence and prodromal physiology. We don't claim to predict the unknown — we surface signals that have shown reproducible association with headache onset across multiple studies.
Each module contributes a 0–100 contribution and a confidence weight (how reliable the underlying data is for you). The daily score is a weighted blend; the UI shows the top drivers, never just a number.
Environmental triggers
Barometric pressure
Rapid changes in atmospheric pressure are one of the most-cited migraine triggers. The app pulls hourly pressure forecasts from Open-Meteo for your location and looks for the rate-of-change windows that have historically preceded headaches.
Light and screen exposure
Photophobia is a defining feature of migraine. The light module accepts logged screen-time or device sensor data when available and treats sustained bright exposure as an elevating signal.
Physiological triggers
Sleep
Both deprivation and oversleep raise risk. The sleep module ingests total duration, sleep efficiency, and bedtime variability from Apple Health, Health Connect, or Oura Ring.
Heart rate variability (HRV)
Reduced HRV correlates with autonomic stress, a known prodromal signal. Pulled from the same health source as sleep.
Hormones
Cycle-related migraine has its own evidence base. The hormone module is optional and uses the on-device cycle tracker; nothing leaves the device.
Hydration
Logged water intake compared against personal baselines.
Behavioral triggers
Alcohol
Quantity and time-since-last-drink. Even modest intake near a sensitive window matters.
Caffeine
Both intake spikes and withdrawal show up as triggers. Tracked from logs.
Meals
Time-since-last-meal as a proxy for blood sugar — skipped meals are a common trigger.
Stress
A subjective daily log (1–5) plus any HRV signal as a corroborating biometric.
Activity
Heavy exertion outside your normal pattern can precipitate; absolute sedentary stretches show up too.
Personalization
Generic triggers are a starting point, not the model. Each time you log a headache, the correlation engine looks back at the trigger contributions in the 24–48 hours before onset and updates the per-trigger weights that drive your future scores. After ~10 logs, the score is meaningfully tuned; after ~30 it's stable.
The model lives entirely on the device. No data leaves unless you explicitly export it.
What it isn't
Migraine Forecast is not a medical device. It does not diagnose, treat, or replace clinical care. If your headaches are severe, frequent, or changing in character, see a doctor — the app's job is to help you spot patterns, not to substitute for evaluation.