What's the weather like in Miami in September?
Miami’s in the southeast of the United States close to the Tropic of Cancer. This gives the city warm weather all year round, and temperatures are usually at their peak in September. You'll get more rain over summer although when it does rain, it’s often in short and heavy downpours or storms. This is because humidity’s quite high although the North Atlantic Ocean breeze will help to keep you comfortable.
Averages
The average high in Miami is 31ºC in September, which only drops to 25ºC at night meaning you won’t need to bring many warm clothes. You should probably bring some waterproofs though as there’s 178mm of rain over 17 days. The normal sea temperature is 29ºC, which is perfect for swimming, while humidity’s very high. You can expect nine hours of sunshine from the 12 hours of daylight each day, and UV levels will be very high so bring plenty of sun cream. Sunset’s at 7.40pm at the start of the month and gradually gets earlier.