Pack a light fleece jacket, hoodie, or comfy cardigan for evening dockside drinking. Jeans, leggings, joggers, or lightweight active pants are also practical. They can be easily cuffed during the day and let down when the night chills begin.

You can certainly wear jeans in Key West, but you may find them uncomfortably hot due to the island's tropical humidity and year-round warm temperatures. The unofficial dress code of Key West is "Conch Republic Casual," which prioritizes comfort, breathability, and bright colors. Most visitors and locals opt for lightweight fabrics like linen, cotton, or moisture-wicking synthetics. If you do choose to wear jeans, they are perfectly acceptable for evening dining at most restaurants or bars along Duval Street, as the atmosphere is very laid-back. However, for daytime sightseeing or boat trips, you will likely be much happier in shorts, sundresses, or loose-fitting "island" trousers. If you're visiting in the winter months (January–February), a pair of jeans might actually be useful for cooler, breezy evenings.