The climate is subtropical, due to the islands' position above the Tropic of Cancer. The lowest temperature to hit the Keys was 36F (2C), on Key Largo, due to an Arctic cold front. The Keys claim to be the only place in the mainland USA to never have had a frost.
The two main airports in the Keys are the seaplane base on Marathon Key (ICAO: 42FL) and Key West International Airport  (ICAO: KEYW IATA: EYW). The seaplane baseis only used by private or commuter aircraft, mainly coming in from Miami (ICAO: KMIA IATA: MIA), which is the closest international airport. Key West International airport has scheduled flights to about ten destinations, including Atlanta, Miami, and Tampa.
Greyhound has service to and from the Florida Keys. There are terminals on Marathon, Big Pine Key, and Key West.
Multiple ferry services are available from Fort Myers to Key West. Most of them are large catamarans that will accommodate 20-30 passengers. Sailing time is about 3 hours.
The Keys (at least the accessible, commercial islands) are connected by US Highway 1. A useful and interesting "quirk" about the linearity of the Keys (and US-1) is that directions to establishments and attractions are locally described by the "Mile Markers" along US-1. If you ask someone how to get to a certain beach or hotel, they will tell you that it is at "Mile Marker 68.5"; many signs and brochures will say "MM 68.5" (of course, there is no mile marker 68.5, this just means that the hotel is halfway between mile markers 68 and 69). These numbers start at zero at the start of US-1 on Key West, so the numbers get larger as you go north.
The speed limits in the Keys are generally 45 MPH on the built-up Islands, and 55 MPH on the bridges and less built-up islands. There are areas (very built-up strips, or animal sanctuaries) where the speed drops to 35 MPH.
The Keys are not so much a sightseeing destination—people are coming for the beaches. But that's not to say there are no attractions. The several museums are all on Key West: the Ernest Hemingway Home and Museum, Audubon House & Tropical Gardens, and the Key West Art & History Museum at the Custom House. Islamorada also has a neat artist colony at Rain Barrel, filled with large, unusual statues.
One of the Keys' most popular activities is scuba diving. From Biscayne National Park up to Key West; they all have nice reefs, tropical waters and a very diverse marine life. Some of the popular dive sites are Spiegel Crove, North Dry Rocks and the USNS Vandenberg.
As you would expect, there is a lot of seafood served in the Keys, but all types of restaurants exist. These include most of the staples of American fast-food, mom-and-pop diners, and many kinds of ethnic fare.
The Florida Keys are the birthplace of Key Lime Pie once made using limes exclusively grown here. Nearly every restaurant will have their own variation of this dessert, and each will be quite different, ranging from super-tart to sickly-sweet.
Another Key specialty is conch (pronounced "konk"), a large mollusk often served in chowder. Conch fritters, small spheres of fried breading and conch, are an appetizer you should try at least once during your stay.
practices in the Keys. FWC officers patrol docks, bridges and waters.
Lower Keys and Key West