The Everglades essentially has two seasons, wet and dry. The dry season lasts from December to April. Temperatures are lower than in the wet season and vary between 12-25oC with low humidity. Although this is the busiest time of year, it is a great time to visit the park as there is less water around so animals tend to congregate in deeper pools and are easier to find. There are also far fewer mosquitoes! The wet season lasts from May until November and temperatures are consistently over 30oC with high humidity and frequent (very) heavy rain showers. Watching a thunderstorm travelling over the Everglades however is an amazing sight (provided it is from a safe place, otherwise I imagine it is terrifying).
My favourite time of year to visit the Park is the winter and early spring. The temperatures can be cool but it is always warmer than where I have just come from…..