Friday, April 14, 2006

Florida Climate

The climate of Florida is tempered somewhat by its proximity to water. Most of the state has a humid subtropical climate with the extreme tip of Florida and the Florida Keys bordering on a true tropical climate. Cold fronts can occasionally bring high winds and cool to cold temperatures to the entire state during late fall and winter. One such front swept through the peninsula on November 25, 1996 bringing cold temperatures and winds up to 95 miles per hour (150 km/h), knocking out power to thousands and damaging mobile homes. However, Florida averages 300 days of full sunshine a year. The seasons in Florida are actually determined more by precipitation than by temperature with warm, relatively dry winters and autumns (the dry season) and hot, wet springs and summers (the wet season). The Gulf Stream has a moderating effect on Florida climate, and although it is common for much of Florida to see a high summer temperature over 90 degrees Fahrenheit (32 °C), it is not common for the mercury to go above 100 degrees Fahrenheit (39 °C) in Florida. The hottest temperature ever recorded in the state was 109 °F (43 °C) set on June 29, 1931 in Monticello. The coldest was 2 °F below zero (−19 °C), on February 13, 1899 just 25 miles (40 km) away, in Tallahassee. Mean high temperatures for late July are primarily in the low 90's Fahrenheit (32–35 °C). Mean low temperatures for late January range from the low 40's Fahrenheit (4–7 °C) in northern Florida to the mid-50's (≈13 °C)in southern Florida.

While Florida's nickname is the "Sunshine State", severe weather is a common occurrence in Florida. Central Florida is known as the lightning capital of the U.S. as it experiences more lightning strikes than anywhere else in the country. Statewide, Florida has the highest average precipitation of any state, due in large part to afternoon thunderstorms which are common throughout most of the state from late spring until the early autumn. A sunny day may be interrupted with a storm only to return to regular gorgeous weather. These thunderstorms, which are caused by airflow from the Gulf of Mexico and the Atlantic Ocean colliding over the peninsula, seemingly "pop up" in the early afternoon and can often bring heavy downpours, high winds and sometimes tornadoes. This is frequently due to "onshore flow," or a collision of sea breezes from the east and west coasts. Florida leads the nation in tornadoes per square mile, although the tornadoes in Florida do not get as large as those in the Midwest or Great Plains. Hail often accompanies some of the more severe thunderstorms.

Snow is a rare occurrence in Florida. During the Great Blizzard of 1899, Florida experienced blizzard conditions for possibly the first time since explorers had arrived. During that time, the Tampa Bay Area had "Gulf effect" snow, similar to lake effect snowfall. The Great Blizzard of 1899 was also the only time the temperature has fallen below 0 degrees Fahrenheit (−18 °C). The most widespread snowfall in Florida history happened in February 1978, with snow falling over much of the state in different times of the month, extending as far south as Homestead. Snow flurries fell on Miami Beach for the only time in recorded history. 1982's Cold Sunday, which saw freezing conditions throughout much of the country, ruined that year's orange crops. In 1989, there was a severe hard freeze that created lots of ice and also caused minor flurries in sections of the state and resulted in rolling blackouts due to power failures caused by massive demands on the power grid for heating.

Although some storms have formed out of season, hurricanes pose a threat during hurricane season, which is from June 1 to November 30. Florida saw a slew of destruction in 2004 when it was hit by a record four hurricanes. Hurricanes Charley (August 13), Frances (September 4-5), Ivan (September 16), and Jeanne (September 25-26) cumulatively cost US$42 billion to the state. In 2005, Hurricane Dennis (July 10) became the fifth storm to strike Florida within 11 months. Later, Hurricane Katrina (August 25) passed through South Florida and Hurricane Rita (September 20) swept through the Florida Keys. Hurricane Wilma made landfall in Florida in the early morning of October 24 as a Category 3 hurricane, with storm's eye hitting near Cape Romano, just south of Marco Island, according to National Hurricane Center.

Florida was also the site of the second most costly single weather disaster in U.S. history, Hurricane Andrew, which caused more than US$25 billion in damage when it struck on August 24, 1992. Among a long list of other infamous hurricane strikes are the 1926 Great Miami Hurricane, the Lake Okeechobee Hurricane of 1928, the Labor Day Hurricane of 1935, Hurricane Donna in 1960, and Hurricane Opal in 1995.