Weather & Climate

It's Not the Cold, It's the Humidity

Florida’s thick humidity persists even in winter and presents a surprising challenge to staying warm. During winter, sweat and moisture from the air cling to clothing and do not evaporate, causing a persistent chill. The damp permeates everything, getting up under clothes and into sleeping bags. After hiking the High Sierras, the White Mountains, and Maine, we've found that 40 degrees in Florida is much colder than 40 degrees up north or in the high mountains where the air is dry. Think of it as an effect like wind chill.

It's Not the Heat, Either

In order to carry heat away from the body, sweat must evaporate. High humidity inhibits evaporation, as the already moist air will not accept more moisture, makes staying cool challenging.

To mitigate the humidity, we recommend the following:

• a synthetic rather than down sleeping bag — down absorbs moisture from the air and dries slowly
• a fleece jacket rather than a nylon jack stuffed with insulation — the nylon is clammy and does not carry moisture away from your body, additionally fleece insulates better when wet
• no cotton anything, even underwear
  
• sneakers instead of leather boots
  

After the summer solstice, the sun sinks closer and closer to the southern horizon until it seems to barely climb above the horizons at all — if you live in the north.

Florida's latitude of between 25 and 30 degrees means that even on the winter solstice the sun is still high and bright. It also means you can get sunburnt on a cloudy day. Counter-intuitive yes, but it has happened to us many times.

Nor do forests provide little respite from the sun. The Trail winds through pine flatwoods, which are so open that cars could easily drive through them, as well as scrubs and prairies that provide virtually no cover. Levy and roadwalks are usually exposed with no shade. Even Big Cypress, the great swamp, leaves hikers exposed to direct sun much of the time.

We don't recommend applying sunscreen every day — it's difficult to stay clean on a thru-hike and greasy sunscreen makes that all the more difficult. Instead, dress like the cowboys did: wear a wide-brimmed hat, a long sleeve shirt, long pants, and sunglasses.

On the Appalachian Trail, it often rains for days at a time, drenching hikers, but they slog on and deal with the dampness. On the AT, the biggest threat rain presents is a loss of core body temperature. A functional waterproof jacket and pants mitigates this threat. The rain on the AT however, even the heaviest rain, is a drizzle compared to a Florida thunderstorm. The rain here is more intense than people from out of state realize and it starts quickly.

Fortunately for thru-hikers, they do not have to contend with many thunderstorms, but the last 100 miles of the Trail can be very stormy. If a thunderstorm rolls in on you, do not keep hiking as if on the AT. Take cover immediately.

Central Florida lies at latitude 28 degrees north, a latitude shared with the Mexican desert, the Sahara Desert, and the Middle East — not places known for cool, damp weather. The only reason Florida is not a desert itself, is its peninsular shape, which creates thunderstorms.

During the day, the sun heats the land faster than the surrounding water. The air over the peninsula rises, and the comparatively cooler air above the Atlantic and Gulf of Mexico rolls in to fill the empty space left by the rising air (low pressure in meteorological terms). As the two moist bodies of air collide they create huge thunderstorms. Like clockwork in summer months, this cycle plays out as thunderheads boil every afternoon.

Tampa is the lightning capital of the United States and nearly every storm in Florida has lightning. Fortunately for Florida Trail thru-hikers, the most violent storms with the most lightning occur in the summer. Winter storms are mild, unless your hike runs into April when spring storms begin hitting the far western end of Florida (see above).