Japan
Best Time to Dive in Okinawa
26.19°N 127.33°E
Dive it January to May, clear of the storm season — the months either side see a tropical storm in 33% of years. The marine life holds steady all year, so the weather picks the month.
- Best time
- Jan–May
- Water
- 22–29 °C
- Visibility
- 20–30 m
- Dived from
- day boat
- Tidal range
- 1.0–2.0 m
- Species logged
- 4
Worth knowing: 46% of days see seas over 1.5 m.
Where it is
111 km across · coastline from Natural Earth 10m
Diving in Okinawa — 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 | Moderate | Moderate | Poor | Poor | Moderate | Excellent | Moderate |
| Water temp (°C) | 23 | 22 | 22 | 23 | 25 | 27 | 29 | 29 | 29 | 28 | 26 | 24 |
| Visibility (m) | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 | 20–30 |
| Marine life | Steady | Steady | Steady | Steady | Steady | Steady | Steady | Steady | Steady | Steady | Steady | Steady |
| Best time | Peak | Peak | Peak | Peak | Peak |
Excellent Good Moderate PoorPeak season Jan–May
Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.
The Okinawa diving season
January to May · Peak season
5 monthsJFMAMJJASOND
- Water temperature
- 22–25 °C
- Visibility
- 20–30 m
- Rain
- 13 days a month
Diving conditionsSwell is common, and crossings can be rough.
June to July · Shoulder season
2 monthsJFMAMJJASOND
- Water temperature
- 27–29 °C
- Visibility
- 20–30 m
- Rain
- 14 days a month
Diving conditionsExpect some swell.
August to September · Off season
2 monthsJFMAMJJASOND
- Water temperature
- 29–29 °C
- Visibility
- 20–30 m
- Rain
- 16 days a month
Diving conditionsThe wind eases. The sea is calmer.
October to November · Shoulder season
2 monthsJFMAMJJASOND
- Water temperature
- 26–28 °C
- Visibility
- 20–30 m
- Rain
- 12 days a month
Diving conditionsSwell is common, and crossings can be rough.
December · Shoulder season
1 monthJFMAMJJASOND
- Water temperature
- 24–24 °C
- Visibility
- 20–30 m
- Rain
- 14 days a month
Diving conditionsSwell is common, and crossings can be rough. The wind is up.
- Spring tides run 2.0 m against 1.0 m on neaps, so currents build around the full and new moon.
- Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
- Visibility is estimated from satellite chlorophyll-a.
Okinawa water temperature and weather
1,945 underwater observation records · 24 surveyed years of ocean data · 10 years of sea temperature
Water & weather
Okinawa 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
14
rough days a month
Seas top 1.5 m on 46% of days. Enough to cancel a day boat
7
blowy days a month
Gusts over 40 km/h, about where a day boat stays in port
14
wet days a month
5 of them bring heavy rain
| Month | Swell | Gusts over 40 km/h | Wet days | Heavy rain | Air | Daylight |
|---|---|---|---|---|---|---|
| January | 2.8 m | 35% | 13 | 4 | 20 °C | 10.5 h |
| February | 2.6 m | 35% | 12 | 3 | 20 °C | 11.1 h |
| March | 2.5 m | 24% | 13 | 4 | 21 °C | 11.8 h |
| April | 2.1 m | 16% | 12 | 6 | 23 °C | 12.6 h |
| May | 2.0 m | 8% | 16 | 7 | 25 °C | 13.3 h |
| June | 2.0 m | 11% | 17 | 9 | 28 °C | 13.6 h |
| July | 2.9 m | 17% | 12 | 4 | 29 °C | 13.5 h |
| August | 2.3 m | 17% | 15 | 4 | 29 °C | 12.9 h |
| September | 2.9 m | 20% | 16 | 6 | 29 °C | 12.1 h |
| October | 2.8 m | 27% | 12 | 4 | 27 °C | 11.4 h |
| November | 2.6 m | 33% | 12 | 3 | 25 °C | 10.7 h |
| December | 3.1 m | 47% | 14 | 4 | 22 °C | 10.4 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: Good | February week 1: Good | March week 1: Good | April week 1: Excellent | May week 1: Excellent | June week 1: Poor | July week 1: Good | August week 1: Poor | September week 1: Poor | October week 1: Moderate | November week 1: Excellent | December week 1: Moderate |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week 2 | January week 2: Excellent | February week 2: Excellent | March week 2: Excellent | April week 2: Excellent | May week 2: Excellent | June week 2: Moderate | July week 2: Good | August week 2: Poor | September week 2: Poor | October week 2: Moderate | November week 2: Excellent | December week 2: Moderate |
| Week 3 | January week 3: Good | February week 3: Good | March week 3: Excellent | April week 3: Excellent | May week 3: Excellent | June week 3: Moderate | July week 3: Poor | August week 3: Moderate | September week 3: Poor | October week 3: Moderate | November week 3: Good | December week 3: Moderate |
| Week 4 | January week 4: Good | February week 4: Good | March week 4: Excellent | April week 4: Excellent | May week 4: Good | June week 4: Good | July week 4: Poor | August week 4: Moderate | September week 4: Poor | October week 4: Poor | November week 4: Good | December week 4: Moderate |
Excellent Good Moderate PoorBest week to go: fourth of April
January, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 23 °C | 2.5 m | 36 km/h | 48% |
| Week 2 | Excellent | 23 °C | 2.7 m | 36 km/h | 44% |
| Week 3 | Good | 23 °C | 3.1 m | 37 km/h | 42% |
| Week 4 | Good | 23 °C | 3.1 m | 36 km/h | 41% |
February, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 22 °C | 2.7 m | 36 km/h | 42% |
| Week 2 | Excellent | 22 °C | 2.5 m | 36 km/h | 40% |
| Week 3 | Good | 22 °C | 2.6 m | 36 km/h | 41% |
| Week 4 | Good | 22 °C | 2.7 m | 36 km/h | 45% |
March, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 22 °C | 2.4 m | 34 km/h | 47% |
| Week 2 | Excellent | 22 °C | 2.4 m | 32 km/h | 42% |
| Week 3 | Excellent | 22 °C | 2.4 m | 32 km/h | 37% |
| Week 4 | Excellent | 22 °C | 2.4 m | 33 km/h | 40% |
April, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 23 °C | 2.2 m | 32 km/h | 39% |
| Week 2 | Excellent | 23 °C | 2.2 m | 31 km/h | 39% |
| Week 3 | Excellent | 23 °C | 2.0 m | 31 km/h | 46% |
| Week 4 | Excellent | 24 °C | 1.6 m | 31 km/h | 46% |
May, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 24 °C | 1.6 m | 30 km/h | 44% |
| Week 2 | Excellent | 25 °C | 1.7 m | 29 km/h | 46% |
| Week 3 | Excellent | 25 °C | 2.0 m | 29 km/h | 53% |
| Week 4 | Good | 26 °C | 2.7 m | 30 km/h | 59% |
June, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 26 °C | 2.9 m | 29 km/h | 59% |
| Week 2 | Moderate | 27 °C | 2.1 m | 31 km/h | 64% |
| Week 3 | Moderate | 27 °C | 1.9 m | 32 km/h | 58% |
| Week 4 | Good | 28 °C | 1.5 m | 30 km/h | 42% |
July, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 28 °C | 1.8 m | 29 km/h | 37% |
| Week 2 | Good | 29 °C | 2.0 m | 28 km/h | 34% |
| Week 3 | Poor | 29 °C | 3.0 m | 28 km/h | 38% |
| Week 4 | Poor | 29 °C | 4.1 m | 27 km/h | 46% |
August, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 4.1 m | 28 km/h | 51% |
| Week 2 | Poor | 29 °C | 2.7 m | 26 km/h | 49% |
| Week 3 | Moderate | 29 °C | 1.8 m | 24 km/h | 44% |
| Week 4 | Moderate | 30 °C | 2.3 m | 24 km/h | 45% |
September, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 2.7 m | 25 km/h | 56% |
| Week 2 | Poor | 29 °C | 2.7 m | 25 km/h | 60% |
| Week 3 | Poor | 29 °C | 3.0 m | 27 km/h | 52% |
| Week 4 | Poor | 29 °C | 2.9 m | 28 km/h | 45% |
October, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 28 °C | 2.6 m | 30 km/h | 39% |
| Week 2 | Moderate | 28 °C | 2.4 m | 32 km/h | 39% |
| Week 3 | Moderate | 28 °C | 2.5 m | 33 km/h | 42% |
| Week 4 | Poor | 27 °C | 2.9 m | 35 km/h | 37% |
November, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 27 °C | 2.8 m | 36 km/h | 34% |
| Week 2 | Excellent | 26 °C | 2.8 m | 35 km/h | 41% |
| Week 3 | Good | 26 °C | 2.9 m | 36 km/h | 45% |
| Week 4 | Good | 26 °C | 2.6 m | 37 km/h | 45% |
December, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 25 °C | 2.7 m | 39 km/h | 47% |
| Week 2 | Moderate | 25 °C | 3.0 m | 39 km/h | 42% |
| Week 3 | Moderate | 24 °C | 3.2 m | 39 km/h | 42% |
| Week 4 | Moderate | 24 °C | 3.1 m | 37 km/h | 48% |
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: 5 mm | May: 5 mm | June: 3 mm | July: skin | August: skin | September: skin | October: 3 mm | November: 3 mm | December: 5 mm |
- Dec–May5 mm full suit
- Jun3 mm full suit
- Jul–Sepskin or 3 mm shorty
- Oct–Nov3 mm full suit
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
20 of the last 30 Septembers saw a tropical storm pass within 250 km. Anything has been recorded Apr–Oct.
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
Okinawa marine life — what you'll see diving
| Species | When | Observed window | Reliability | Evidence | Records |
|---|---|---|---|---|---|
| Humpback whale | Feb–Mar | Near-guaranteed | 1158 | ||
| Green turtle | All year | Near-guaranteed | 725 | ||
| Hawksbill turtle | All year | Likely | 26 | ||
| Whitetip reef shark | Feb, Dec | Hit-or-miss | 8 |
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 Okinawa — common questions
- When is the best time to dive Okinawa?
- Dive it January to May, clear of the storm season — the months either side see a tropical storm in 33% of years. The marine life holds steady all year, so the weather picks the month.
- When is the diving season in Okinawa?
- The diving season in Okinawa runs January to May.
- Is the diving in Okinawa good for beginners?
- Yes. It suits Open Water divers, so it works for a first trip after certification.
- How warm is the water in Okinawa?
- Between 22 and 29 °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 Okinawa?
- 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 Okinawa?
- Roughly 20 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 Okinawa?
- The most consistently recorded species are Humpback whale (near-guaranteed), Green turtle (near-guaranteed) and Hawksbill turtle (likely), from 1,945 records within 60 km.
- Does Okinawa get tropical storms?
- Yes. Over 30 years of records a storm passed within 250 km in Apr–Oct, most often in September at 20 of 30 years.
- Is there current in Okinawa?
- The tide rises and falls 2.0 m around the full and new moon, against 1.0 m in between. How much of that becomes current depends on the shape of the channel.
- When should I avoid Okinawa?
- September is the weakest month for conditions.
- How do you dive Okinawa?
- Mostly from day boats. Trips run through the season, Jan–May.