Complex sentence: Snow has not fallen on its top in at least the past 100 years however, there have been mild flurries occurred in the mountain especially during December, January and February, also frost is more common in the mountain due to the low temperature during those months.
Split into simpler sentences: Snow has not fallen on its top in at least the past 100 years; however, there have been mild flurries on the mountain, especially during December, January and February. Frost is more common on the mountain due to the low temperature during those months.