Aftr evry 2 or 3 years,on the start of summer, one sided headache starts occuring on daily basis which lasts for 2months or so,is it sinus or migrain?

Likely a migraine: First, you need to figure out the real cause of your headache pain. It has been estimated that approximately 70% of migraine headaches overlie the sinuses and are triggered by changes in barometric pressure (e.g. diving). Rec.: see your orofacial pain or headache specialist for evaluation, diagnostic and treatment. Further investigation is only needed to determine the best treatment.