Thailand
Best Time to Dive in Koh Phi Phi
7.70°N 98.77°E
The best conditions run December to April, when the downpours ease — 2 days a month of heavy rain instead of 9. Too few records to show a wildlife season, so the weather picks the month.
- Best time
- Dec–Apr
- Water
- 29–31 °C
- Visibility
- 10–25 m
- Dived from
- day boat
- Tidal range
- 1.1–2.5 m
- Species logged
- 4
Where it is
111 km across · coastline from Natural Earth 10m
Diving in Koh Phi Phi — 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 | Poor | Moderate | Poor | Poor | Poor | Poor | Poor | Good |
| Water temp (°C) | 29 | 29 | 30 | 31 | 31 | 30 | 30 | 30 | 30 | 29 | 29 | 29 |
| Visibility (m) | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 10–20 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 | 15–25 |
| Marine life | Busy | Steady | Peak | Peak | Steady | Steady | Steady | Busy | Steady | Busy | Steady | Steady |
| Best time | Peak | Peak | Peak | Peak | Peak |
Excellent Good Moderate PoorPeak season Dec–Apr
Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.
The Koh Phi Phi diving season
May to November · Off season
7 monthsJFMAMJJASOND
- Water temperature
- 29–31 °C
- Visibility
- 15–25 m
- Rain
- 24 days a month
Diving conditionsThe sea is rougher. It rains more.
Marine lifeWhale shark (hit-or-miss) peaks at Koh Phi Phi in these months.
December to April · Peak season
5 monthsJFMAMJJASOND
- Water temperature
- 29–31 °C
- Visibility
- 15–25 m
- Rain
- 12 days a month
Diving conditionsThe sea is calmer. It rains less.
Marine lifeWhale shark (hit-or-miss) peaks at Koh Phi Phi in these months.
- Spring tides run 2.5 m against 1.1 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.
Koh Phi Phi water temperature and weather
195 underwater observation records · 22 surveyed years of ocean data · 10 years of sea temperature
Water & weather
Koh Phi Phi 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 1.5 m on 2% 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
19
wet days a month
6 of them bring heavy rain
| Month | Swell | Gusts over 40 km/h | Wet days | Heavy rain | Air | Daylight |
|---|---|---|---|---|---|---|
| January | 0.7 m | 0% | 9 | 1 | 29 °C | 11.6 h |
| February | 0.7 m | 0% | 6 | 0 | 30 °C | 11.8 h |
| March | 0.6 m | 0% | 11 | 1 | 30 °C | 11.9 h |
| April | 0.6 m | 0% | 21 | 4 | 30 °C | 12.2 h |
| May | 1.1 m | 1% | 26 | 9 | 30 °C | 12.4 h |
| June | 1.2 m | 1% | 21 | 7 | 29 °C | 12.4 h |
| July | 1.5 m | 2% | 20 | 8 | 29 °C | 12.4 h |
| August | 1.2 m | 1% | 22 | 8 | 29 °C | 12.3 h |
| September | 1.4 m | 3% | 23 | 10 | 29 °C | 12.0 h |
| October | 1.1 m | 0% | 28 | 11 | 29 °C | 11.8 h |
| November | 0.7 m | 0% | 25 | 9 | 29 °C | 11.6 h |
| December | 0.6 m | 0% | 15 | 3 | 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: Good | February week 1: Excellent | March week 1: Excellent | April week 1: Excellent | May week 1: Moderate | June week 1: Poor | July week 1: Moderate | August week 1: Poor | September week 1: Poor | October week 1: Poor | November week 1: Poor | December week 1: Moderate |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Week 2 | January week 2: Good | February week 2: Excellent | March week 2: Excellent | April week 2: Good | May week 2: Moderate | June week 2: Moderate | July week 2: Poor | August week 2: Poor | September week 2: Poor | October week 2: Poor | November week 2: Moderate | December week 2: Moderate |
| Week 3 | January week 3: Good | February week 3: Excellent | March week 3: Excellent | April week 3: Good | May week 3: Poor | June week 3: Moderate | July week 3: Poor | August week 3: Poor | September week 3: Poor | October week 3: Poor | November week 3: Moderate | 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: Poor | June week 4: Moderate | July week 4: Poor | August week 4: Poor | September week 4: Poor | October week 4: Poor | November week 4: Poor | December week 4: Excellent |
Excellent Good Moderate PoorBest week to go: second of March
January, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Good | 29 °C | 0.6 m | 25 km/h | 31% |
| Week 2 | Good | 29 °C | 0.6 m | 25 km/h | 31% |
| Week 3 | Good | 29 °C | 0.7 m | 25 km/h | 32% |
| Week 4 | Excellent | 29 °C | 0.7 m | 25 km/h | 23% |
February, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 29 °C | 0.7 m | 25 km/h | 16% |
| Week 2 | Excellent | 29 °C | 0.6 m | 24 km/h | 18% |
| Week 3 | Excellent | 29 °C | 0.7 m | 25 km/h | 23% |
| Week 4 | Excellent | 29 °C | 0.7 m | 26 km/h | 22% |
March, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 29 °C | 0.7 m | 24 km/h | 21% |
| Week 2 | Excellent | 29 °C | 0.6 m | 23 km/h | 23% |
| Week 3 | Excellent | 30 °C | 0.6 m | 22 km/h | 32% |
| Week 4 | Good | 30 °C | 0.5 m | 22 km/h | 55% |
April, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Excellent | 30 °C | 0.5 m | 21 km/h | 64% |
| Week 2 | Good | 30 °C | 0.6 m | 21 km/h | 59% |
| Week 3 | Good | 31 °C | 0.6 m | 21 km/h | 68% |
| Week 4 | Excellent | 31 °C | 0.5 m | 20 km/h | 83% |
May, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 31 °C | 0.7 m | 19 km/h | 88% |
| Week 2 | Moderate | 31 °C | 0.9 m | 19 km/h | 89% |
| Week 3 | Poor | 31 °C | 1.1 m | 20 km/h | 86% |
| Week 4 | Poor | 30 °C | 1.3 m | 21 km/h | 81% |
June, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 30 °C | 1.4 m | 22 km/h | 73% |
| Week 2 | Moderate | 30 °C | 1.2 m | 22 km/h | 62% |
| Week 3 | Moderate | 30 °C | 1.1 m | 22 km/h | 68% |
| Week 4 | Moderate | 30 °C | 1.2 m | 22 km/h | 69% |
July, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 30 °C | 1.2 m | 22 km/h | 66% |
| Week 2 | Poor | 30 °C | 1.5 m | 24 km/h | 70% |
| Week 3 | Poor | 30 °C | 1.5 m | 23 km/h | 63% |
| Week 4 | Poor | 30 °C | 1.2 m | 24 km/h | 63% |
August, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 30 °C | 1.1 m | 26 km/h | 69% |
| Week 2 | Poor | 30 °C | 1.1 m | 25 km/h | 71% |
| Week 3 | Poor | 30 °C | 1.1 m | 25 km/h | 70% |
| Week 4 | Poor | 30 °C | 1.3 m | 23 km/h | 73% |
September, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 30 °C | 1.4 m | 23 km/h | 76% |
| Week 2 | Poor | 30 °C | 1.3 m | 25 km/h | 77% |
| Week 3 | Poor | 30 °C | 1.3 m | 25 km/h | 76% |
| Week 4 | Poor | 29 °C | 1.4 m | 23 km/h | 77% |
October, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 1.1 m | 21 km/h | 86% |
| Week 2 | Poor | 29 °C | 0.9 m | 21 km/h | 90% |
| Week 3 | Poor | 29 °C | 1.2 m | 20 km/h | 87% |
| Week 4 | Poor | 29 °C | 1.1 m | 20 km/h | 88% |
November, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Poor | 29 °C | 0.9 m | 20 km/h | 89% |
| Week 2 | Moderate | 29 °C | 0.7 m | 20 km/h | 86% |
| Week 3 | Moderate | 29 °C | 0.6 m | 21 km/h | 84% |
| Week 4 | Poor | 29 °C | 0.7 m | 24 km/h | 80% |
December, week by week
| Week | Conditions | Water | Swell | Wind | Rain chance |
|---|---|---|---|---|---|
| Week 1 | Moderate | 29 °C | 0.6 m | 25 km/h | 65% |
| Week 2 | Moderate | 29 °C | 0.6 m | 24 km/h | 53% |
| Week 3 | Good | 29 °C | 0.6 m | 23 km/h | 47% |
| Week 4 | Excellent | 29 °C | 0.6 m | 24 km/h | 34% |
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 1.5 m.
Tides
Tropical storms
1 of the last 30 Januarys saw a tropical storm pass within 250 km. January is the only month with a recorded pass.
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
Koh Phi Phi marine life — what you'll see diving
Only 195 records have been logged within 60 km. A thin record is not an empty reef.
| Species | When | Observed window | Reliability | Evidence | Records |
|---|---|---|---|---|---|
| Blacktip reef shark | All year | Likely | 81 | ||
| Hawksbill turtle | All year | Likely | 35 | ||
| Zebra shark | Mar–Apr, Oct | Near-guaranteed | 35 | ||
| Whale shark | Jan, Mar–Apr, Aug | Hit-or-miss | 17 |
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 Koh Phi Phi — common questions
- When is the best time to dive Koh Phi Phi?
- The best conditions run December to April, when the downpours ease — 2 days a month of heavy rain instead of 9. Too few records to show a wildlife season, so the weather picks the month.
- When is the diving season in Koh Phi Phi?
- The diving season in Koh Phi Phi runs December to April.
- Is the diving in Koh Phi Phi good for beginners?
- Yes. It suits Open Water divers, so it works for a first trip after certification.
- How warm is the water in Koh Phi Phi?
- Between 29 and 31 °C at the surface across the year, coldest in January and warmest in May. It runs cooler below the thermocline.
- What wetsuit do I need in Koh Phi Phi?
- 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 Koh Phi Phi?
- Roughly 10 to 25 m depending on the month. That is estimated from satellite chlorophyll-a rather than measured in the water.
- What will I see diving Koh Phi Phi?
- The most consistently recorded species are Blacktip reef shark (likely), Hawksbill turtle (likely) and Zebra shark (near-guaranteed), from 195 records within 60 km.
- Does Koh Phi Phi get tropical storms?
- Yes. Over 30 years of records a storm passed within 250 km in Jan, most often in January at 1 of 30 years.
- Is there current in Koh Phi Phi?
- The tide rises and falls 2.5 m around the full and new moon, against 1.1 m in between. How much of that becomes current depends on the shape of the channel.
- When should I avoid Koh Phi Phi?
- July, September are the weakest months for conditions.
- How do you dive Koh Phi Phi?
- Mostly from day boats. Trips run through the season, Dec–Apr.