USA · Dry Tortugas
Best Time to Dive in Dry Tortugas, Florida Keys
24.63°N 82.87°W
Aim for March to July for the long days — 12.9 hours of light against 11.4. The marine life holds steady all year, so the weather picks the month. Diving holds up from February to July.
- Best time
- Mar–Jul
- Water
- 24–30 °C
- Visibility
- 15–30 m
- Season runs
- Feb–Jul
- Dived from
- liveaboard
- Tidal range
- 0.3–0.7 m
- Species logged
- 12
Where it is
111 km across · coastline from Natural Earth 10m
Diving in Dry Tortugas, Florida Keys — monthly breakdown
A year of scuba diving conditions at a glance. Hover a month to isolate it.
| January | February | March | April | May | June | July | August | September | October | November | December | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Conditions | Good | Good | Excellent | Excellent | Excellent | Excellent | Excellent | Poor | Poor | Poor | Poor | Moderate |
| Water temp (°C) | 24 | 24 | 24 | 25 | 27 | 29 | 30 | 30 | 30 | 29 | 27 | 25 |
| Visibility (m) | 15–25 | 15–25 | 20–30 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 |
| Marine life | Peak | Busy | Peak | Busy | Peak | Peak | Peak | Busy | Peak | Busy | Quiet | Steady |
| Best time | Peak | Peak | Peak | Peak | Peak |
Excellent Good Moderate PoorPeak season Mar–Jul
Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.
The Dry Tortugas, Florida Keys diving season
January to July · Peak season
7 monthsJFMAMJJASOND
- Water temperature
- 24–30 °C
- Visibility
- 15–25 m
- Rain
- 8 days a month
Diving conditionsExpect some swell. It rains less.
Marine lifeGoliath grouper (likely) peaks at Dry Tortugas, Florida Keys in these months.
August to November · Off season
4 monthsJFMAMJJASOND
- Water temperature
- 27–30 °C
- Visibility
- 15–25 m
- Rain
- 14 days a month
Diving conditionsSeas stay mostly calm. It rains more.
December · Shoulder season
1 monthJFMAMJJASOND
- Water temperature
- 25–25 °C
- Visibility
- 15–25 m
- Rain
- 6 days a month
Diving conditionsThe sea is rougher. The wind is up.
- Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
- Visibility is estimated from satellite chlorophyll-a.
Florida Keys water temperature and weather
884 underwater observation records · 32 surveyed years of ocean data · 10 years of sea temperature
Water & weather
Dry Tortugas, Florida Keys water temperature by month
The dashed line is the monthly average. Eight days in ten fall inside the band.
10th to 90th percentile rangemonthly mean
Rarely
rough enough to cancel
Seas top 2.5 m on 2% of days. Enough to cancel a liveaboard crossing
2
blowy days a month
Gusts over 40 km/h, about where a day boat stays in port
10
wet days a month
2 of them bring heavy rain
| Month | Swell | Gusts over 40 km/h | Wet days | Heavy rain | Air | Daylight |
|---|---|---|---|---|---|---|
| January | 2.0 m | 16% | 8 | 2 | 23 °C | 10.6 h |
| February | 1.8 m | 10% | 5 | 1 | 23 °C | 11.2 h |
| March | 1.9 m | 12% | 3 | 1 | 24 °C | 11.8 h |
| April | 1.7 m | 5% | 5 | 1 | 25 °C | 12.6 h |
| May | 1.1 m | 3% | 8 | 3 | 27 °C | 13.2 h |
| June | 1.2 m | 3% | 15 | 3 | 29 °C | 13.5 h |
| July | 1.0 m | 1% | 14 | 1 | 30 °C | 13.4 h |
| August | 1.2 m | 5% | 16 | 3 | 30 °C | 12.9 h |
| September | 1.1 m | 5% | 18 | 4 | 29 °C | 12.1 h |
| October | 1.8 m | 12% | 16 | 4 | 28 °C | 11.4 h |
| November | 2.1 m | 13% | 8 | 2 | 26 °C | 10.8 h |
| December | 1.9 m | 14% | 6 | 1 | 24 °C | 10.5 h |
Swell is the rough end of the month: nine days in ten come in under it. Sea temperature covers 10 years, waves 4.
Pick your week
48 weeks from the daily record. Darker is better, against this site's own year. Pick a month for the detail.
| Week 1 | January week 1: Moderate | February week 1: Good | March week 1: Excellent | April week 1: Excellent | May week 1: Excellent | June week 1: Good | July week 1: Excellent | August week 1: Poor | September week 1: Poor | October week 1: Poor | November week 1: Poor | December week 1: Good |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week 2 | January week 2: Good | February week 2: Moderate | March week 2: Good | April week 2: Excellent | May week 2: Excellent | June week 2: Good | July week 2: Excellent | August week 2: Poor | September week 2: Poor | October week 2: Poor | November week 2: Poor | December week 2: Moderate |
| Week 3 | January week 3: Moderate | February week 3: Excellent | March week 3: Good | April week 3: Good | May week 3: Excellent | June week 3: Good | July week 3: Excellent | August week 3: Poor | September week 3: Poor | October week 3: Poor | November week 3: Poor | December week 3: Poor |
| Week 4 | January week 4: Good | February week 4: Excellent | March week 4: Excellent | April week 4: Excellent | May week 4: Good | June week 4: Excellent | July week 4: Good | August week 4: Poor | September week 4: Poor | October week 4: Moderate | November week 4: Moderate | December week 4: Good |
Excellent Good Moderate PoorBest week to go: first of July
January, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 24 °C | 1.8 m | 30 km/h | 26% |
| Week 2 | Good | 24 °C | 2.0 m | 32 km/h | 25% |
| Week 3 | Moderate | 24 °C | 2.1 m | 32 km/h | 25% |
| Week 4 | Good | 23 °C | 2.0 m | 30 km/h | 24% |
February, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 23 °C | 2.1 m | 29 km/h | 22% |
| Week 2 | Moderate | 23 °C | 2.0 m | 29 km/h | 18% |
| Week 3 | Excellent | 24 °C | 1.8 m | 29 km/h | 16% |
| Week 4 | Excellent | 24 °C | 1.5 m | 28 km/h | 14% |
March, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 24 °C | 1.5 m | 28 km/h | 12% |
| Week 2 | Good | 24 °C | 1.9 m | 29 km/h | 12% |
| Week 3 | Good | 24 °C | 2.0 m | 29 km/h | 12% |
| Week 4 | Excellent | 25 °C | 1.9 m | 28 km/h | 10% |
April, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 25 °C | 1.8 m | 28 km/h | 10% |
| Week 2 | Excellent | 25 °C | 1.7 m | 29 km/h | 14% |
| Week 3 | Good | 25 °C | 1.7 m | 29 km/h | 20% |
| Week 4 | Excellent | 26 °C | 1.6 m | 28 km/h | 20% |
May, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 26 °C | 1.3 m | 27 km/h | 17% |
| Week 2 | Excellent | 27 °C | 1.1 m | 26 km/h | 21% |
| Week 3 | Excellent | 27 °C | 1.1 m | 26 km/h | 29% |
| Week 4 | Good | 28 °C | 1.2 m | 25 km/h | 33% |
June, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 28 °C | 1.2 m | 24 km/h | 47% |
| Week 2 | Good | 28 °C | 1.2 m | 24 km/h | 58% |
| Week 3 | Good | 29 °C | 1.2 m | 23 km/h | 49% |
| Week 4 | Excellent | 29 °C | 1.1 m | 22 km/h | 40% |
July, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 30 °C | 0.9 m | 21 km/h | 38% |
| Week 2 | Excellent | 30 °C | 0.8 m | 23 km/h | 39% |
| Week 3 | Excellent | 30 °C | 1.0 m | 23 km/h | 48% |
| Week 4 | Good | 30 °C | 1.1 m | 23 km/h | 51% |
August, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 30 °C | 1.2 m | 23 km/h | 46% |
| Week 2 | Poor | 30 °C | 1.1 m | 22 km/h | 44% |
| Week 3 | Poor | 30 °C | 0.9 m | 22 km/h | 52% |
| Week 4 | Poor | 30 °C | 1.1 m | 24 km/h | 61% |
September, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 30 °C | 1.1 m | 23 km/h | 61% |
| Week 2 | Poor | 30 °C | 1.0 m | 21 km/h | 60% |
| Week 3 | Poor | 30 °C | 0.9 m | 20 km/h | 58% |
| Week 4 | Poor | 30 °C | 2.0 m | 23 km/h | 59% |
October, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 2.2 m | 27 km/h | 62% |
| Week 2 | Poor | 29 °C | 1.8 m | 29 km/h | 60% |
| Week 3 | Poor | 29 °C | 2.0 m | 29 km/h | 50% |
| Week 4 | Moderate | 28 °C | 1.9 m | 31 km/h | 37% |
November, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 28 °C | 2.1 m | 31 km/h | 31% |
| Week 2 | Poor | 27 °C | 2.1 m | 30 km/h | 30% |
| Week 3 | Poor | 27 °C | 1.9 m | 30 km/h | 26% |
| Week 4 | Moderate | 26 °C | 2.0 m | 29 km/h | 17% |
December, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 26 °C | 1.8 m | 29 km/h | 13% |
| Week 2 | Moderate | 25 °C | 2.2 m | 30 km/h | 17% |
| Week 3 | Poor | 25 °C | 2.3 m | 31 km/h | 23% |
| Week 4 | Good | 25 °C | 1.8 m | 30 km/h | 26% |
10 years of daily records, averaged into weeks.
Gear & storms
What to wear
Off the coldest water of each month, not the average — that is what the suit has to cope with.
| January | February | March | April | May | June | July | August | September | October | November | December | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Suit | January: 5 mm | February: 5 mm | March: 5 mm | April: 3 mm | May: 3 mm | June: skin | July: skin | August: skin | September: skin | October: skin | November: 3 mm | December: 3 mm |
- Jan–Mar5 mm full suit
- Apr–May3 mm full suit
- Jun–Octskin or 3 mm shorty
- Nov–Dec3 mm full suit
Swell through the year
The rough end of each month — nine days in ten come in under it.
Amber is over 2.5 m.
Tides
Tropical storms
10 of the last 30 Augusts saw a tropical storm pass within 250 km. Anything has been recorded May–Nov.
Share of the last 30 years with a storm that month.
- NOAASea surface temperature, from OISST and MUR
- ERA5Wind, waves, rain and air temperature, via Open-Meteo
- OBISMarine species records within 60 km
- IBTrACSTropical cyclone tracks, 1996 to 2025
Dry Tortugas, Florida Keys marine life — what you'll see diving
| Species | When | Observed window | Reliability | Evidence | Records |
|---|---|---|---|---|---|
| Nurse shark | Jun–Jul | Likely | 143 | ||
| Nassau grouper | May–Jun | Hit-or-miss | 68 | ||
| Green turtle | Jan, Mar | Hit-or-miss | 31 | ||
| Yellowfin tuna | Jan–Mar | Hit-or-miss | 60 | ||
| Spotted eagle ray | Jun, Aug | Hit-or-miss | 24 | ||
| Silky shark | Feb | Hit-or-miss | 56 | ||
| Loggerhead turtle | Jan, Mar, Sep | Near-guaranteed | 46 | ||
| Bull shark | May | Hit-or-miss | 8 | ||
| Goliath grouper | Jan, May–Jul | Likely | 224 | ||
| Southern stingray | Feb–Mar, Jun, Sep | Likely | 62 | ||
| Bottlenose dolphin | Feb–Mar, Sep | Hit-or-miss | 26 | ||
| Lemon shark | Mar, Dec | Hit-or-miss | 12 |
Peak Present
- Observed window
- Months with records. Peak is where most of them fall.
- Reliability
- Near-guaranteed in 60% of surveyed years or more
- Likely 30% to 60%
- Hit-or-miss under 30%
- Evidence
- Years it was seen, out of the years anyone surveyed.
- Records
- OBIS sightings within 60 km.
These are sightings people logged, not a full survey of the reef. A species missing from a month may just mean nobody recorded one.
Diving Dry Tortugas, Florida Keys — common questions
- When is the best time to dive Dry Tortugas, Florida Keys?
- Aim for March to July for the long days — 12.9 hours of light against 11.4. The marine life holds steady all year, so the weather picks the month. Diving holds up from February to July.
- When is the diving season in Dry Tortugas, Florida Keys?
- The diving season in Dry Tortugas, Florida Keys runs February to July, and it is at its best March to July.
- Is the diving in Dry Tortugas, Florida Keys good for beginners?
- It is better with some experience. It suits Advanced Open Water divers or equivalent, so newer divers should ask the local operator which sites fit their level.
- How warm is the water in Dry Tortugas, Florida Keys?
- Between 24 and 30 °C at the surface across the year, coldest in February and warmest in August. It runs cooler below the thermocline.
- What wetsuit do I need in Dry Tortugas, Florida Keys?
- A 5 mm full suit covers the coldest water of the year. In the warmest months a skin or 3 mm shorty is enough.
- What is the visibility like in Dry Tortugas, Florida Keys?
- Roughly 15 to 30 m depending on the month. That is estimated from satellite chlorophyll-a rather than measured in the water.
- What will I see diving Dry Tortugas, Florida Keys?
- The most consistently recorded species are Nurse shark (likely), Nassau grouper (hit-or-miss) and Green turtle (hit-or-miss), from 884 records within 60 km.
- Does Dry Tortugas, Florida Keys get tropical storms?
- Yes. Over 30 years of records a storm passed within 250 km in May–Nov, most often in August at 10 of 30 years.
- Is there current in Dry Tortugas, Florida Keys?
- The tide rises and falls 0.7 m around the full and new moon, against 0.3 m in between. How much of that becomes current depends on the shape of the channel.
- When should I avoid Dry Tortugas, Florida Keys?
- August, November are the weakest months for conditions.
- How do you dive Dry Tortugas, Florida Keys?
- Mostly from liveaboards. Trips run through the season, Feb–Jul.