Marathon and the other Florida Keys boast some of the year-round weather in the country. The location near the Gulf of Mexico and Gulf Stream creates pleasant temperatures ranging from the mid-60s to the low-90s and temperatures seldom differ by more than ten degrees from day to night or summer to winter.
Seasonal Temperatures in Marathon, FL
Come and enjoy the Florida sunshine in the Keys! With great weather all year round, late summer and fall tend to be the most unpredictable in terms of tropical storms and hurricanes. Be sure you plan accordingly for your upcoming trip to the Gulf of Mexico. Use our seasonal weather chart and guide to plan when to visit the Florida Keys for your next vacation!
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec | |
| Average High | 76 | 78 | 80 | 84 | 87 | 89 | 91 | 91 | 89 | 86 | 81 | 78 |
| Average Low | 65 | 67 | 69 | 73 | 77 | 79 | 80 | 80 | 79 | 77 | 72 | 68 |
