Florida Keys Weather by Month
Florida Keys is a chain of tropical islands located off the southern tip of Florida, USA. The Florida Keys feature a tropical marine climate with a warm, wet season from June through November and a comfortable, dry season from December through May. Temperatures remain warm throughout the year, while ocean temperatures range from about 74°F in winter to 86°F in late summer.
Florida Keys Weather by Month
You can click the image below to view the full-size weather chart for Florida Keys.
January – Cool, Windy and Mostly Clear
Average high: 74°F
Average low: 66°F
Rainfall: 1.5 inches
Water Temperature: 74°F
Daylight: 10.7 hours
January is the coolest month of the year in the Florida Keys. Average daytime temperatures reach around 74°F, while nighttime temperatures can fall to about 66°F.
Rainfall averages only 1.5 inches, making January one of the drier months. Conditions are generally windy and mostly clear, while the water temperature averages around 74°F.
With mild winter temperatures, relatively little rain and comfortable daylight hours, January is well suited to exploring the islands and enjoying outdoor activities.
Best for:
- Outdoor sightseeing
- Boating and fishing
- Winter getaways
- Clear-sky photography
February – Clear Skies and Low Humidity
Average high: 76°F
Average low: 67°F
Rainfall: 1.6 inches
Water Temperature: 74°F
Daylight: 11.3 hours
February brings slightly warmer weather, with average highs of 76°F and lows around 67°F.
Rainfall remains low at 1.6 inches, and clear skies peak during this month. Humidity is also relatively low, creating comfortable conditions for spending time outdoors. Water temperatures remain around 74°F.
The combination of warm temperatures, low rainfall and clear skies makes February a comfortable month for exploring the Florida Keys.
Best for:
- Beach activities
- Boating
- Fishing
- Outdoor sightseeing
March – Dry and Warming Spring Weather
Average high: 78°F
Average low: 70°F
Rainfall: 1.5 inches
Water Temperature: 75°F
Daylight: 12.0 hours
March continues the dry season while temperatures begin to rise. Average daytime temperatures reach around 78°F, while nighttime temperatures stay near 70°F.
Rainfall averages just 1.5 inches, making March one of the driest months of the year. Water temperatures increase slightly to around 75°F as warmer spring weather arrives.
Longer daylight hours and dry conditions make March a good month for enjoying outdoor activities throughout the Florida Keys.
Best for:
- Island sightseeing
- Fishing
- Boating
- Outdoor activities
April – Bright, Sunny and Warm
Average high: 81°F
Average low: 73°F
Rainfall: 1.7 inches
Water Temperature: 77°F
Daylight: 12.7 hours
April brings warmer temperatures, with average highs reaching 81°F and nighttime lows around 73°F.
Rainfall remains relatively low at 1.7 inches, and April is described as bright and sunny. Water temperatures rise to around 77°F, making conditions increasingly comfortable for swimming and other water activities.
The longer daylight hours also provide plenty of time for sightseeing, boating and enjoying the beaches.
Best for:
- Beach days
- Swimming
- Snorkeling
- Boating
May – Warm and Increasingly Humid
Average high: 84°F
Average low: 77°F
Rainfall: 3.5 inches
Water Temperature: 80°F
Daylight: 13.4 hours
May marks the transition toward the wetter part of the year. Average highs climb to 84°F, while nighttime temperatures reach around 77°F.
Rainfall increases to 3.5 inches, and humidity and the chance of rain begin to rise toward late May. At the same time, water temperatures reach a warm 80°F.
The combination of warm air, warm water and long daylight hours makes May suitable for swimming, snorkeling and other water-based activities.
Best for:
- Swimming
- Snorkeling
- Boating
- Warm-weather vacations
June – Hot, Wet and Tropical
Average high: 87°F
Average low: 80°F
Rainfall: 5.6 inches
Water Temperature: 83°F
Daylight: 13.7 hours
June marks the official start of the hot and wet season in the Florida Keys. Average daytime temperatures reach 87°F, while nighttime temperatures remain around 80°F.
Rainfall increases to 5.6 inches, and ocean temperatures become very warm at around 83°F. The combination of hot weather, warm water and frequent rainfall creates typical tropical summer conditions.
June also has some of the longest daylight hours of the year, providing plenty of time for outdoor activities between rain showers.
Best for:
- Swimming
- Snorkeling
- Diving
- Tropical summer activities
July – Hot, Humid and Calm
Average high: 89°F
Average low: 81°F
Rainfall: 4.3 inches
Water Temperature: 85°F
Daylight: 13.5 hours
July is one of the hottest months in the Florida Keys, with average highs of 89°F and lows around 81°F.
Rainfall averages 4.3 inches, while conditions are characterized by calmer winds and hot, humid summer weather. Water temperatures rise to around 85°F.
The very warm ocean makes July well suited to swimming, snorkeling, diving and boating, although visitors should be prepared for high humidity.
Best for:
- Swimming
- Snorkeling
- Diving
- Boating
August – Hottest Month and Warmest Water
Average high: 89°F
Average low: 81°F
Rainfall: 5.2 inches
Water Temperature: 86°F
Daylight: 13.0 hours
August is the hottest month of the year in the Florida Keys. Average highs reach 89°F, while nighttime temperatures remain around 81°F.
Rainfall averages 5.2 inches, and humidity and mugginess reach their peak. Water temperatures are also at their warmest, averaging about 86°F.
The extremely warm ocean provides comfortable conditions for water activities, while the heat and humidity can make extended outdoor activities more demanding.
Best for:
- Swimming
- Snorkeling
- Diving
- Warm-water activities
September – Wettest and Cloudiest Month
Average high: 87°F
Average low: 80°F
Rainfall: 6.1 inches
Water Temperature: 85°F
Daylight: 12.3 hours
September remains hot, with average highs around 87°F and lows near 80°F.
It is the wettest and cloudiest month in the supplied data, with rainfall reaching about 6.1 inches. There is also potential for tropical storm conditions. Water temperatures remain very warm at around 85°F.
Visitors in September should be prepared for changing weather and allow flexibility when planning outdoor activities.
Best for:
- Warm-water swimming
- Snorkeling during favorable weather
- Flexible tropical trips
- Indoor attractions
October – Warm and Transitioning to Drier Weather
Average high: 84°F
Average low: 77°F
Rainfall: 4.2 inches
Water Temperature: 82°F
Daylight: 11.7 hours
October brings a gradual transition out of the wet season. Average highs remain warm at 84°F, while nighttime temperatures fall to around 77°F.
Rainfall decreases to 4.2 inches, and skies begin clearing toward late October. Water temperatures remain warm at approximately 82°F.
With rainfall declining and temperatures becoming slightly more comfortable, October is a useful transition month for outdoor activities in the Florida Keys.
Best for:
- Swimming
- Boating
- Fishing
- Outdoor sightseeing
November – Warm, Windy and Increasingly Dry
Average high: 80°F
Average low: 72°F
Rainfall: 1.9 inches
Water Temperature: 79°F
Daylight: 11.0 hours
November brings cooler and drier conditions compared with the summer months. Average daytime temperatures reach around 80°F, while nighttime temperatures fall to about 72°F.
Rainfall drops to only 1.9 inches, and November is described as the windiest month of the year as drier, cooler air begins to arrive. Water temperatures remain warm at around 79°F.
The combination of warm temperatures and lower rainfall makes November a comfortable transition into the dry season.
Best for:
- Fishing
- Boating
- Outdoor sightseeing
- Warm-weather escapes
December – Dry and Pleasant Winter Weather
Average high: 76°F
Average low: 68°F
Rainfall: 1.4 inches
Water Temperature: 76°F
Daylight: 10.6 hours
December is the driest month of the year in the Florida Keys, with rainfall averaging just 1.4 inches.
Average daytime temperatures reach around 76°F, while nighttime temperatures remain mild at approximately 68°F. Water temperatures average 76°F, keeping the ocean relatively warm even during the winter season.
With pleasant temperatures, low rainfall and comfortable daylight hours, December provides typical dry-season weather and is well suited to outdoor activities and winter escapes.
Best for:
- Winter escapes
- Boating and fishing
- Beach activities
- Outdoor sightseeing
Florida Keys Weather by Month
| Month | Avg High °F (°C) | Avg Low °F (°C) | Rainfall (inches) | Water Temperature | Daylight (hours) |
|---|---|---|---|---|---|
| January | 74°F (23.3°C) | 66°F (18.9°C) | 1.5 | 74°F | 10.7 |
| February | 76°F (24.4°C) | 67°F (19.4°C) | 1.6 | 74°F | 11.3 |
| March | 78°F (25.6°C) | 70°F (21.1°C) | 1.5 | 75°F | 12.0 |
| April | 81°F (27.2°C) | 73°F (22.8°C) | 1.7 | 77°F | 12.7 |
| May | 84°F (28.9°C) | 77°F (25.0°C) | 3.5 | 80°F | 13.4 |
| June | 87°F (30.6°C) | 80°F (26.7°C) | 5.6 | 83°F | 13.7 |
| July | 89°F (31.7°C) | 81°F (27.2°C) | 4.3 | 85°F | 13.5 |
| August | 89°F (31.7°C) | 81°F (27.2°C) | 5.2 | 86°F | 13.0 |
| September | 87°F (30.6°C) | 80°F (26.7°C) | 6.1 | 85°F | 12.3 |
| October | 84°F (28.9°C) | 77°F (25.0°C) | 4.2 | 82°F | 11.7 |
| November | 80°F (26.7°C) | 72°F (22.2°C) | 1.9 | 79°F | 11.0 |
| December | 76°F (24.4°C) | 68°F (20.0°C) | 1.4 | 76°F | 10.6 |
Florida Keys Weather FAQs
1. What is the weather like in the Florida Keys?
The Florida Keys have a tropical marine climate with warm temperatures throughout the year. The dry season generally runs from December through May, while June through November is warmer and wetter.
2. What is the coldest month in the Florida Keys?
January is the coolest month, with an average high of 74°F and an average low of 66°F.
3. What is the hottest month in the Florida Keys?
July and August are the hottest months, with average highs of 89°F and average lows of 81°F.
4. What is the warmest month for water in the Florida Keys?
August has the warmest average water temperature at about 86°F.
5. What is the water temperature in the Florida Keys in January?
The average water temperature in January is about 74°F.
6. What is the water temperature in the Florida Keys in summer?
Water temperatures are very warm during summer, averaging about 83°F in June, 85°F in July, 86°F in August, and 85°F in September.
7. What is the rainiest month in the Florida Keys?
September is the wettest month in the supplied data, with average rainfall of about 6.1 inches.
8. What is the driest month in the Florida Keys?
December is the driest month, with average rainfall of approximately 1.4 inches.
9. Does it rain a lot in the Florida Keys?
Rainfall varies considerably by season. December through April are relatively dry, while rainfall increases during the summer and early fall, reaching 6.1 inches in September.
10. When is the dry season in the Florida Keys?
The comfortable, dry season generally runs from December through May.
11. When is the wet season in the Florida Keys?
The warm, wet season runs from June through November.
12. What is the average temperature in the Florida Keys in winter?
Winter is mild compared with many other destinations. Average highs range from 74°F to 76°F, while average lows range from 66°F to 68°F from December through February.
13. Is January a good month to visit the Florida Keys?
January offers relatively cool, mostly clear and dry conditions, with an average high of 74°F and only about 1.5 inches of rainfall.
14. Is February rainy in the Florida Keys?
February is relatively dry, receiving about 1.6 inches of rainfall. It is also characterized by clear skies and relatively low humidity.
15. Is March a rainy month in the Florida Keys?
March is one of the drier months, with about 1.5 inches of rainfall and average temperatures of 78°F during the day and 70°F at night.
16. Is the Florida Keys weather humid in summer?
Yes. Summer is hot and humid, particularly in July and August. August is described in the supplied data as having peak mugginess.
17. Is September a good month for outdoor activities in the Florida Keys?
September can still provide very warm conditions and an average water temperature of 85°F, but it is also the wettest and cloudiest month, with potential tropical storm risks. Flexible outdoor plans are advisable.
18. What month has the longest daylight in the Florida Keys?
June has the longest daylight in the data used for the article, at approximately 13.7 hours per day.
19. What month has the shortest daylight in the Florida Keys?
December has approximately 10.6 hours of daylight, making it the month with the shortest daylight period in the article’s data.
20. What is the best time of year for warm and relatively dry weather in the Florida Keys?
December through May generally combines warm temperatures with relatively low rainfall. During this period, average highs increase from about 74–76°F in winter to 84°F in May, while rainfall remains comparatively low through April.
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