USVI
Best Time to Dive in St. Croix
17.79°N 64.77°W
The animals show up September to October. 23% of years see a tropical storm pass within 250 km then, while the calmest water is February to June. Diving holds up from November to July.
- Best time
- Sep–Oct
- Water
- 27–30 °C
- Visibility
- 20–35 m
- Season runs
- Nov–Jul
- Dived from
- day boat and shore diving
- Tidal range
- 0.1–0.3 m
- Species logged
- 10
Worth knowing: 23% of years see a tropical storm pass within 250 km.
Where it is
111 km across · coastline from Natural Earth 10m
Diving in St. Croix — 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 | Excellent | Excellent | Excellent | Excellent | Excellent | Excellent | Good | Poor | Moderate | Good | Good | Good |
| Water temp (°C) | 27 | 27 | 27 | 27 | 28 | 29 | 29 | 29 | 30 | 29 | 29 | 28 |
| Visibility (m) | 25–35 | 25–35 | 25–35 | 25–35 | 25–35 | 25–35 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 25–35 |
| Marine life | Steady | Steady | Steady | Steady | Steady | Peak | Steady | Steady | Peak | Peak | Steady | Steady |
| Best time | Peak | Peak |
Excellent Good Moderate PoorPeak season Sep–Oct
Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.
The St. Croix diving season
August to September · Off season
2 monthsJFMAMJJASOND
- Water temperature
- 29–30 °C
- Visibility
- 20–30 m
- Rain
- 21 days a month
Diving conditionsThe sea is calmer. It rains more.
Marine lifeGoliath grouper (hit-or-miss) peaks at St. Croix in these months.
October to July · Peak season
10 monthsJFMAMJJASOND
- Water temperature
- 27–29 °C
- Visibility
- 25–35 m
- Rain
- 17 days a month
Diving conditionsRain is frequent topside. The sea is rougher.
Marine lifeGoliath grouper (hit-or-miss) peaks at St. Croix in these months.
- Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
- Visibility is estimated from satellite chlorophyll-a.
St. Croix water temperature and weather
1,941 underwater observation records · 31 surveyed years of ocean data · 10 years of sea temperature
Water & weather
St. Croix 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
3
rough days a month
Seas top 1.5 m on 9% of days. Enough to cancel a day boat
0
blowy days a month
Gusts over 40 km/h, about where a day boat stays in port
17
wet days a month
2 of them bring heavy rain
| Month | Swell | Gusts over 40 km/h | Wet days | Heavy rain | Air | Daylight |
|---|---|---|---|---|---|---|
| January | 1.6 m | 2% | 16 | 0 | 27 °C | 11.0 h |
| February | 1.6 m | 0% | 13 | 1 | 27 °C | 11.4 h |
| March | 1.6 m | 1% | 14 | 0 | 28 °C | 11.9 h |
| April | 1.5 m | 0% | 17 | 1 | 28 °C | 12.4 h |
| May | 1.3 m | 0% | 19 | 2 | 29 °C | 12.8 h |
| June | 1.4 m | 0% | 16 | 1 | 30 °C | 13.1 h |
| July | 1.5 m | 2% | 19 | 3 | 30 °C | 13.0 h |
| August | 1.4 m | 2% | 21 | 3 | 30 °C | 12.6 h |
| September | 1.2 m | 4% | 21 | 3 | 30 °C | 12.1 h |
| October | 1.2 m | 0% | 20 | 5 | 30 °C | 11.6 h |
| November | 1.4 m | 0% | 18 | 4 | 29 °C | 11.1 h |
| December | 1.6 m | 3% | 15 | 0 | 28 °C | 10.9 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: Excellent | February week 1: Good | March week 1: Excellent | April week 1: Excellent | May week 1: Excellent | June week 1: Excellent | July week 1: Good | August week 1: Poor | September week 1: Moderate | October week 1: Good | November week 1: Good | December week 1: Excellent |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week 2 | January week 2: Excellent | February week 2: Good | March week 2: Excellent | April week 2: Excellent | May week 2: Excellent | June week 2: Excellent | July week 2: Good | August week 2: Poor | September week 2: Moderate | October week 2: Good | November week 2: Good | December week 2: Good |
| Week 3 | January week 3: Excellent | February week 3: Excellent | March week 3: Excellent | April week 3: Excellent | May week 3: Excellent | June week 3: Excellent | July week 3: Good | August week 3: Poor | September week 3: Moderate | October week 3: Good | November week 3: Good | December week 3: Good |
| Week 4 | January week 4: Excellent | February week 4: Excellent | March week 4: Good | April week 4: Excellent | May week 4: Excellent | June week 4: Good | July week 4: Good | August week 4: Poor | September week 4: Moderate | October week 4: Good | November week 4: Good | December week 4: Good |
Excellent Good Moderate PoorBest week to go: second of October
January, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 27 °C | 1.4 m | 24 km/h | 49% |
| Week 2 | Excellent | 27 °C | 1.5 m | 24 km/h | 52% |
| Week 3 | Excellent | 27 °C | 1.6 m | 24 km/h | 48% |
| Week 4 | Excellent | 27 °C | 1.7 m | 24 km/h | 49% |
February, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 27 °C | 1.6 m | 26 km/h | 51% |
| Week 2 | Good | 27 °C | 1.8 m | 27 km/h | 48% |
| Week 3 | Excellent | 27 °C | 1.7 m | 27 km/h | 45% |
| Week 4 | Excellent | 27 °C | 1.4 m | 25 km/h | 42% |
March, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 27 °C | 1.5 m | 23 km/h | 40% |
| Week 2 | Excellent | 27 °C | 1.6 m | 23 km/h | 40% |
| Week 3 | Excellent | 27 °C | 1.5 m | 24 km/h | 49% |
| Week 4 | Good | 27 °C | 1.5 m | 24 km/h | 49% |
April, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 27 °C | 1.6 m | 24 km/h | 45% |
| Week 2 | Excellent | 27 °C | 1.6 m | 23 km/h | 52% |
| Week 3 | Excellent | 27 °C | 1.4 m | 23 km/h | 60% |
| Week 4 | Excellent | 27 °C | 1.3 m | 23 km/h | 69% |
May, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 28 °C | 1.2 m | 23 km/h | 69% |
| Week 2 | Excellent | 28 °C | 1.3 m | 23 km/h | 57% |
| Week 3 | Excellent | 28 °C | 1.3 m | 23 km/h | 54% |
| Week 4 | Excellent | 28 °C | 1.2 m | 23 km/h | 65% |
June, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 28 °C | 1.2 m | 24 km/h | 63% |
| Week 2 | Excellent | 28 °C | 1.3 m | 25 km/h | 53% |
| Week 3 | Excellent | 29 °C | 1.4 m | 26 km/h | 52% |
| Week 4 | Good | 29 °C | 1.6 m | 26 km/h | 56% |
July, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 29 °C | 1.7 m | 27 km/h | 56% |
| Week 2 | Good | 29 °C | 1.5 m | 27 km/h | 60% |
| Week 3 | Good | 29 °C | 1.5 m | 27 km/h | 61% |
| Week 4 | Good | 29 °C | 1.4 m | 26 km/h | 66% |
August, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 1.4 m | 26 km/h | 71% |
| Week 2 | Poor | 29 °C | 1.5 m | 26 km/h | 69% |
| Week 3 | Poor | 29 °C | 1.6 m | 25 km/h | 69% |
| Week 4 | Poor | 29 °C | 1.3 m | 24 km/h | 62% |
September, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 29 °C | 1.2 m | 23 km/h | 63% |
| Week 2 | Moderate | 29 °C | 1.2 m | 22 km/h | 67% |
| Week 3 | Moderate | 30 °C | 1.2 m | 21 km/h | 69% |
| Week 4 | Moderate | 30 °C | 1.2 m | 21 km/h | 75% |
October, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 30 °C | 1.2 m | 21 km/h | 72% |
| Week 2 | Good | 30 °C | 1.1 m | 20 km/h | 66% |
| Week 3 | Good | 29 °C | 1.3 m | 21 km/h | 61% |
| Week 4 | Good | 29 °C | 1.4 m | 22 km/h | 62% |
November, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 29 °C | 1.4 m | 22 km/h | 71% |
| Week 2 | Good | 29 °C | 1.4 m | 23 km/h | 70% |
| Week 3 | Good | 29 °C | 1.4 m | 22 km/h | 58% |
| Week 4 | Good | 29 °C | 1.4 m | 21 km/h | 49% |
December, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 28 °C | 1.4 m | 22 km/h | 42% |
| Week 2 | Good | 28 °C | 1.7 m | 24 km/h | 48% |
| Week 3 | Good | 28 °C | 1.7 m | 24 km/h | 53% |
| Week 4 | Good | 28 °C | 1.5 m | 24 km/h | 47% |
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: 3 mm | February: 3 mm | March: 3 mm | April: 3 mm | May: skin | June: skin | July: skin | August: skin | September: skin | October: skin | November: skin | December: skin |
- Jan–Apr3 mm full suit
- May–Decskin or 3 mm shorty
Swell through the year
The rough end of each month — nine days in ten come in under it.
Amber is over 1.5 m.
Tides
Tropical storms
13 of the last 30 Augusts saw a tropical storm pass within 250 km. Anything has been recorded Jul–Dec.
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
St. Croix marine life — what you'll see diving
| Species | When | Observed window | Reliability | Evidence | Records |
|---|---|---|---|---|---|
| Southern stingray | All year | Near-guaranteed | 251 | ||
| Spotted eagle ray | All year | Near-guaranteed | 179 | ||
| Hawksbill turtle | All year | Near-guaranteed | 54 | ||
| Green turtle | All year | Likely | 341 | ||
| Yellowfin tuna | All year | Hit-or-miss | 113 | ||
| Nassau grouper | Jun, Sep–Oct | Near-guaranteed | 286 | ||
| Humpback whale | Jan, Mar | Hit-or-miss | 9 | ||
| Nurse shark | Jun, Sep–Oct | Near-guaranteed | 210 | ||
| Lemon shark | Jun, Sep–Oct | Likely | 49 | ||
| Goliath grouper | Jun, Sep | Hit-or-miss | 24 |
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 St. Croix — common questions
- When is the best time to dive St. Croix?
- The animals show up September to October. 23% of years see a tropical storm pass within 250 km then, while the calmest water is February to June. Diving holds up from November to July.
- When is the diving season in St. Croix?
- Conditions are good November to July, but most divers come September to October for the marine life.
- Is the diving in St. Croix good for beginners?
- Yes. It suits Open Water divers, so it works for a first trip after certification.
- How warm is the water in St. Croix?
- Between 27 and 30 °C at the surface across the year, coldest in February and warmest in September. It runs cooler below the thermocline.
- What wetsuit do I need in St. Croix?
- A 3 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 St. Croix?
- Roughly 20 to 35 m depending on the month. That is estimated from satellite chlorophyll-a rather than measured in the water.
- What will I see diving St. Croix?
- The most consistently recorded species are Southern stingray (near-guaranteed), Spotted eagle ray (near-guaranteed) and Hawksbill turtle (near-guaranteed), from 1,941 records within 60 km.
- Does St. Croix get tropical storms?
- Yes. Over 30 years of records a storm passed within 250 km in Jul–Dec, most often in August at 13 of 30 years.
- Is there current in St. Croix?
- The tide rises and falls 0.3 m around the full and new moon, against 0.1 m in between. How much of that becomes current depends on the shape of the channel.
- When should I avoid St. Croix?
- August is the weakest month for conditions.
- How do you dive St. Croix?
- Mostly from day boats and the shore. Trips run through the season, Nov–Jul.