I have just not been able to figure out all the things that trigger my migraines - they sure suck, though!!! Extreme heat is one thing - getting off the plane in tropical climates has been a trigger for me but other times, who knows. I have 2 in 2 days and then have a few days off before getting another set of 2. Maxalt MLT (MLT means the pill melts in your mouth) really works well for me but I use others, too, so I do not become immune to any particular pill.
I really, really hate my migraines, though. I used to be in absolute misery - eyes covered, ears covered, couldn't move - then 8 hours later I'd vomit and 20 minutes after that I was fine. Now after taking 1 pill, I'm fine in 46 minutes!! Thank goodness for science.