Marathon, Florida Keys weather in January
Temperature, sea and sunshine in January: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in January
Good
Best time to visit: March – May, July, November – December
What is the weather like in Marathon, Florida Keys in January?
In January, Marathon, Florida Keys is warm: daytime highs average 22 °C, and even at night it stays warm at around 20 °C. The sea averages 23.6 °C – pleasant for swimming. The sun shines for around 7 hours a day. Rain falls on about 6 days, adding up to 31 mm. It is often windy, with gusts of around 30 km/h. All in all, January is a good month for a holiday in Marathon, Florida Keys.
January compared
How the weather changes from December to February. Tap a month to open it.
| DecemberDec | JanuaryJan | FebruaryFeb | |
|---|---|---|---|
| Score | 83 | 74 | 81 |
| Day | 24° | 22° | 23° |
| Night | 22° | 20° | 21° |
| Sea | 25° | 24° | 24° |
| Sun | 7 h | 7 h | 7 h |
| Rain days | 5 | 6 | 4 |
More details for January
- Daylight
- 10 h 45 min07:10 – 17:56
- UV index
- 5 · moderateclear sky, noon (estimate)All months
- Muggy days
- 14 daysdew point 18 °C or moreAll months
- Wind
- 30 km/haverage daily peakAll months
- Cloud cover
- 45 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Time zone
- UTC−5America/New_York
How the score comes together
- Temperatureweight 35 %57 %
- Seaweight 25 %94 %
- Sunshineweight 20 %62 %
- Few rainy daysweight 20 %89 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in January
- Swimwear
- Sunscreen
- Windproof jacket
Marathon, Florida Keys in January: quick answers
Is Marathon, Florida Keys hot in January?
Warm rather than hot: in January, daytime highs in Marathon, Florida Keys average 22 °C and nights cool to about 20 °C.
Can you swim in Marathon, Florida Keys in January?
Yes. In January the sea averages 23.6 °C – pleasant for swimming.
Does it rain much in Marathon, Florida Keys in January?
Rain falls on about 6 days, adding up to 31 mm.
Marathon, Florida Keys month by month
The whole year in Marathon, Florida KeysAll destinations: USAFlorida weather in JanuaryWhere to go in JanuarySea temperature in January
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences