Orlando's climate is transitional, with many characteristics of a tropical climate, even though Orlando is technically situated on the southern fringe of the humid subtropical climate zone, Köppen climate classification Cfa. There are two major seasons each year. One is hot and rainy, lasting from June until late September (roughly coinciding with the Atlantic hurricane season). The other is the dry, warm season (October through May) bringing less frequent rainfall, yet still with warm temperatures. The area's warm and humid climate is caused primarily by its low elevation, its position relatively close to the Tropic of Cancer, and its location in the center of a peninsula. Many characteristics of its climate are a result of its proximity to the Gulf Stream, which flows around the peninsula of Florida.