Micronesia
Best Time to Dive in Chuuk (Truk) Lagoon
7.39°N 151.90°E
The wildlife shows no season worth planning around, so it comes down to the weather: go August to October.
- Best time
- Aug–Oct
- Water
- 29–30 °C
- Visibility
- 20–30 m
- Dived from
- liveaboard and day boat
- Tidal range
- 0.4–0.8 m
- Species logged
- 6
Worth knowing: 12 days a month of heavy rain.
Where it is
111 km across · coastline from Natural Earth 10m
Diving in Chuuk (Truk) Lagoon — 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 | Moderate | Poor | Excellent | Excellent | Good | Good | Moderate | Excellent | Excellent | Poor | Poor |
| Water temp (°C) | 29 | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 30 | 30 | 30 | 29 |
| 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 | Quiet | Peak | Peak | Steady | Steady | Steady | Busy | Busy | Quiet | Quiet |
| Best time | Peak | Peak | Peak |
Excellent Good Moderate PoorPeak season Aug–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 Chuuk (Truk) Lagoon diving season
January to March · Shoulder season
3 monthsJFMAMJJASOND
- Water temperature
- 29–29 °C
- Visibility
- 20–30 m
- Rain
- 20 days a month
Diving conditionsRain is frequent topside. The wind is up. The sea is rougher.
April to October · Peak season
7 monthsJFMAMJJASOND
- Water temperature
- 29–30 °C
- Visibility
- 20–30 m
- Rain
- 27 days a month
Diving conditionsThis is the wet season topside. The wind eases. The sea is calmer.
November to December · Off season
2 monthsJFMAMJJASOND
- Water temperature
- 29–30 °C
- Visibility
- 20–30 m
- Rain
- 26 days a month
Diving conditionsThis is the wet season topside. The wind is up. The sea is rougher.
- Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
- Visibility is estimated from satellite chlorophyll-a.
Chuuk (Truk) Lagoon water temperature and weather
218 underwater observation records · 10 surveyed years of ocean data · 10 years of sea temperature
Water & weather
Chuuk (Truk) Lagoon 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 under 1% 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
25
wet days a month
12 of them bring heavy rain
| Month | Swell | Gusts over 40 km/h | Wet days | Heavy rain | Air | Daylight |
|---|---|---|---|---|---|---|
| January | 1.8 m | 17% | 21 | 8 | 29 °C | 11.6 h |
| February | 1.8 m | 27% | 17 | 5 | 28 °C | 11.8 h |
| March | 1.6 m | 6% | 20 | 9 | 28 °C | 12.0 h |
| April | 1.6 m | 3% | 25 | 11 | 29 °C | 12.2 h |
| May | 1.4 m | 1% | 28 | 14 | 29 °C | 12.3 h |
| June | 1.2 m | 0% | 27 | 15 | 29 °C | 12.4 h |
| July | 1.3 m | 0% | 29 | 16 | 29 °C | 12.4 h |
| August | 1.2 m | 1% | 28 | 15 | 29 °C | 12.2 h |
| September | 1.2 m | 0% | 27 | 13 | 29 °C | 12.0 h |
| October | 1.4 m | 3% | 28 | 12 | 29 °C | 11.8 h |
| November | 1.3 m | 2% | 27 | 14 | 29 °C | 11.7 h |
| December | 1.6 m | 8% | 25 | 12 | 29 °C | 11.6 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: Moderate | April week 1: Excellent | May week 1: Good | June week 1: Good | July week 1: Moderate | August week 1: Good | September week 1: Excellent | October week 1: Excellent | November week 1: Moderate | December week 1: Moderate |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week 2 | January week 2: Excellent | February week 2: Good | March week 2: Moderate | April week 2: Good | May week 2: Excellent | June week 2: Good | July week 2: Excellent | August week 2: Good | September week 2: Excellent | October week 2: Excellent | November week 2: Poor | December week 2: Poor |
| Week 3 | January week 3: Moderate | February week 3: Good | March week 3: Moderate | April week 3: Excellent | May week 3: Excellent | June week 3: Good | July week 3: Good | August week 3: Good | September week 3: Excellent | October week 3: Excellent | November week 3: Poor | December week 3: Poor |
| Week 4 | January week 4: Moderate | February week 4: Good | March week 4: Moderate | April week 4: Good | May week 4: Good | June week 4: Moderate | July week 4: Excellent | August week 4: Moderate | September week 4: Excellent | October week 4: Good | November week 4: Poor | December week 4: Poor |
Excellent Good Moderate PoorBest week to go: first of October
January, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 29 °C | 1.6 m | 34 km/h | 74% |
| Week 2 | Excellent | 29 °C | 1.8 m | 35 km/h | 70% |
| Week 3 | Moderate | 29 °C | 1.9 m | 36 km/h | 66% |
| Week 4 | Moderate | 29 °C | 1.8 m | 36 km/h | 63% |
February, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 29 °C | 1.8 m | 37 km/h | 59% |
| Week 2 | Good | 29 °C | 1.8 m | 38 km/h | 61% |
| Week 3 | Good | 29 °C | 1.8 m | 37 km/h | 60% |
| Week 4 | Good | 29 °C | 1.8 m | 36 km/h | 55% |
March, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 29 °C | 1.6 m | 35 km/h | 52% |
| Week 2 | Moderate | 29 °C | 1.7 m | 33 km/h | 60% |
| Week 3 | Moderate | 29 °C | 1.7 m | 31 km/h | 75% |
| Week 4 | Moderate | 29 °C | 1.6 m | 32 km/h | 73% |
April, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 29 °C | 1.7 m | 32 km/h | 75% |
| Week 2 | Good | 29 °C | 1.6 m | 31 km/h | 81% |
| Week 3 | Excellent | 29 °C | 1.4 m | 29 km/h | 81% |
| Week 4 | Good | 29 °C | 1.6 m | 30 km/h | 88% |
May, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 29 °C | 1.5 m | 30 km/h | 91% |
| Week 2 | Excellent | 29 °C | 1.4 m | 29 km/h | 91% |
| Week 3 | Excellent | 30 °C | 1.6 m | 28 km/h | 90% |
| Week 4 | Good | 30 °C | 1.4 m | 27 km/h | 87% |
June, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 30 °C | 1.2 m | 26 km/h | 89% |
| Week 2 | Good | 30 °C | 1.2 m | 25 km/h | 92% |
| Week 3 | Good | 30 °C | 1.2 m | 25 km/h | 93% |
| Week 4 | Moderate | 30 °C | 1.3 m | 24 km/h | 92% |
July, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 30 °C | 1.3 m | 23 km/h | 93% |
| Week 2 | Excellent | 30 °C | 1.2 m | 24 km/h | 94% |
| Week 3 | Good | 30 °C | 1.2 m | 23 km/h | 94% |
| Week 4 | Excellent | 30 °C | 1.1 m | 22 km/h | 95% |
August, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 30 °C | 1.3 m | 21 km/h | 93% |
| Week 2 | Good | 30 °C | 1.3 m | 20 km/h | 89% |
| Week 3 | Good | 30 °C | 1.1 m | 20 km/h | 87% |
| Week 4 | Moderate | 30 °C | 1.2 m | 20 km/h | 90% |
September, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 30 °C | 1.2 m | 20 km/h | 89% |
| Week 2 | Excellent | 30 °C | 1.2 m | 21 km/h | 89% |
| Week 3 | Excellent | 30 °C | 1.2 m | 21 km/h | 89% |
| Week 4 | Excellent | 30 °C | 1.2 m | 20 km/h | 86% |
October, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 30 °C | 1.2 m | 20 km/h | 87% |
| Week 2 | Excellent | 30 °C | 1.2 m | 20 km/h | 88% |
| Week 3 | Excellent | 30 °C | 1.3 m | 22 km/h | 89% |
| Week 4 | Good | 30 °C | 1.4 m | 22 km/h | 89% |
November, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 30 °C | 1.2 m | 23 km/h | 87% |
| Week 2 | Poor | 30 °C | 1.2 m | 25 km/h | 92% |
| Week 3 | Poor | 30 °C | 1.3 m | 28 km/h | 95% |
| Week 4 | Poor | 30 °C | 1.4 m | 30 km/h | 91% |
December, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 30 °C | 1.5 m | 31 km/h | 86% |
| Week 2 | Poor | 29 °C | 1.6 m | 33 km/h | 84% |
| Week 3 | Poor | 29 °C | 1.6 m | 34 km/h | 79% |
| Week 4 | Poor | 29 °C | 1.6 m | 34 km/h | 74% |
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: skin | February: skin | March: skin | April: skin | May: skin | June: skin | July: skin | August: skin | September: skin | October: skin | November: skin | December: skin |
One suit covers the whole year: a skin 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 2.5 m.
Tides
Tropical storms
4 of the last 30 Novembers saw a tropical storm pass within 250 km. Anything has been recorded Feb–May, Jul, Nov–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
Chuuk (Truk) Lagoon marine life — what you'll see diving
| Species | When | Observed window | Reliability | Evidence | Records |
|---|---|---|---|---|---|
| Grey reef shark | May | Near-guaranteed | 54 | ||
| Blacktip reef shark | Apr–May | Near-guaranteed | 51 | ||
| Whitetip reef shark | May | Likely | 23 | ||
| Silvertip shark | May | Likely | 30 | ||
| Napoleon wrasse | Apr–May | Likely | 17 | ||
| Bigeye trevally | May, Sep–Oct | Near-guaranteed | 22 |
Peak Present No survey data
- 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 Chuuk (Truk) Lagoon — common questions
- When is the best time to dive Chuuk (Truk) Lagoon?
- The wildlife shows no season worth planning around, so it comes down to the weather: go August to October.
- When is the diving season in Chuuk (Truk) Lagoon?
- The diving season in Chuuk (Truk) Lagoon runs August to October.
- Is the diving in Chuuk (Truk) Lagoon 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 Chuuk (Truk) Lagoon?
- Between 29 and 30 °C at the surface across the year, coldest in February and warmest in October. It runs cooler below the thermocline.
- What wetsuit do I need in Chuuk (Truk) Lagoon?
- A skin or 3 mm shorty covers the coldest water of the year. The same suit works all year.
- What is the visibility like in Chuuk (Truk) Lagoon?
- 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 Chuuk (Truk) Lagoon?
- The most consistently recorded species are Grey reef shark (near-guaranteed), Blacktip reef shark (near-guaranteed) and Whitetip reef shark (likely), from 218 records within 60 km.
- Does Chuuk (Truk) Lagoon get tropical storms?
- Yes. Over 30 years of records a storm passed within 250 km in Feb–May, Jul, Nov–Dec, most often in November at 4 of 30 years.
- Is there current in Chuuk (Truk) Lagoon?
- The tide rises and falls 0.8 m around the full and new moon, against 0.4 m in between. How much of that becomes current depends on the shape of the channel.
- When should I avoid Chuuk (Truk) Lagoon?
- November–December are the weakest months for conditions.
- How do you dive Chuuk (Truk) Lagoon?
- Mostly from liveaboards and day boats. Trips run through the season, Aug–Oct.