The winter weather along the Gold Coast is superb. My favorite time of year. Though "cold" fronts visit from the north from November to March, you can still find acceptable beach days any time of the year within a day or so of a front's passage. When a front comes through, the temperature rarely drops below 50 degrees in the evening almost always returning to the 70's by the next day. Areas along the coast are resistant to dramatic drops in temperature due to the always warm Atlantic waters. I remember one early morning as a kid while surfing immediately after the passage of a cold front (the waves are best at this time) and actually seeing what appeared to be steam rising up from the water! You can easily pick out the tourists after a cold front passes, unlike the natives bundled up as if on an artic expedition, they are wearing "T" shirts with shorts laughing!
Hot!!! The Florida summer is not for the faint of heart! Air conditioning is the greatest invention in human history. The Florida state legislature (the ones who brought you the 2000 presidential election) once tried to outlaw August. Seriously, summer along the Gold Coast can be very enjoyable. Even at its hottest (around August) the off shore breezes and occasional showers provide relief. During this time the temperatures can reach into the high 90's only dropping to the high 70's during the evening. There are sometimes periods of daily afternoon thunderstorms that develop during the summer (though not the last few years). The pattern can last for a week or so and is characterized by hot mornings and heavy thunderstorms rolling in from the west in the early afternoon. You should be aware of a curious phenomena wherein the mainland receives significantly more annual rain fall than the coast. Even during the rare periods daily rain, tourists can still usually muster a tan.
HURRICANES ARE DANGEROUS AND SHOULD NOT BE TAKEN LIGHTLY
I am 42 years old, have lived here all my life and I remember only one hurricane that had any real adverse impact on south Florida. About every three years on comes close enough to send the area rushing to Home Depot for ply wood and batteries. They usually miss completely. Andrew (1992) caused a lot of trouble for the folks down south, but had little effect on the Tourist areas. The media would have had you think that the entire state was ravaged. In fact the affected area was relatively small. Had the storm made a direct hit on the populated tourist areas there surely would have been big trouble. In short, the odds are in your favor that even if one approaches during your stay, it will probably amount to nothing. The risk however is quite grave and you should pay close attention to the advisories should you be here during hurricane season (June thru December peaking in September). When one approaches, many people simply jump in their cars and head for points north or south inland to avoid the threat. This is no guarantee that the storm won't follow you.
During Andrew, it appeared the storm was going to strike the North Dade area (my house, on the water), so I grabbed a few items hard to replace and headed 20 miles south and inland to a friends house in an area know as the Redlands. What a night. The place was destroyed around us. My place had no damage at all. Most loss of life with hurricanes is associated with what they call the storm surge. This occurs on the coast and up to a few miles inland where a hurricane strikes. Areas impacted by a storm surge can be wiped clean ... buildings, trees, everything. The reason there was so little loss of life due to Andrew is because the storm surge occurred in a low population density area. It is a real bad idea to be on the coast when a hurricane hits.