There are three weather-related factors which have an effect on headaches and migraines: temperature, humidity, and atmospheric pressure. You do not have to enter this information on the app. The app retrieves this data itself via GPS (the location service must be enabled on your device).
Temperature: Drastic fluctuations in temperature can contribute to the likelihood of a migraine attack occurring. Before a migraine attack, you may often be more aware of changes in temperature as your sensitivity is heightened. This could be a so-called “early signal”, which is not a cause but an indication of an possible attack.
Humidity: Very high levels of humidity are a common cause of migraine attacks. This is however rarely the case with very low levels of humidity. The intensity of the headache may increase at greater levels of humidity.
Atmospheric Pressure: A rise or a fall in atmospheric pressure are also common causes of migraine attacks. Certain brain cells connected to headaches are more active during a fall in pressure.