INSTRUMENT / SEA TEMPERATURE
Similan Islands Water Temperature
Updated Fri 13:55 (Asia/Bangkok)
Thailand · Forecast updated Nov 6, 2026, 13:55 UTC
Current Sea Temperature
30.6°C
87.1°F
Very warm water
Valid Nov 6, 2026, 13:55 (Asia/Bangkok). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
1.3°C above
The typical November average is 29.3°C (84.7°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 30.1°C, versus 30.0°C in the prior seven days.
What to wear
Very warm water
Swimwear is usually enough; a rash guard adds sun protection.
Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions or replace the snorkel forecast.
Typical Sea Temperature Over the Year
In the historical baseline for Similan Islands, typical monthly averages range from about 28.8°C (83.8°F) in September to 30.8°C (87.4°F) in May.
Over the past 30 days, the average sea temperature in Similan Islands has been 30.0°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Similan Islands, calculated from hourly observations for 2022–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 28.6–29.1°C | 28.9°C / 84.0°F |
| February | 29.0–29.3°C | 29.2°C / 84.6°F |
| March | 29.4–30.3°C | 29.9°C / 85.8°F |
| April | 30.2–31.2°C | 30.6°C / 87.1°F |
| May | 30.1–31.5°C | 30.8°C / 87.4°F |
| June | 29.5–30.3°C | 29.8°C / 85.6°F |
| July | 29.0–29.6°C | 29.3°C / 84.7°F |
| August | 29.1–29.8°C | 29.4°C / 84.9°F |
| September | 28.6–29.0°C | 28.8°C / 83.8°F |
| October | 28.8–29.6°C | 29.2°C / 84.6°F |
| November | 28.8–29.7°C | 29.3°C / 84.7°F |
| December | 28.7–29.3°C | 28.9°C / 84.0°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (8.63, 97.63). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Water temperature by month
Each month uses the 2022–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Similan Islands in January
Typical January water temperature near Similan Islands is 28.9°C (84.0°F), with yearly monthly means from 28.6–29.1°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: December 28.9°C · February 29.2°C.
Explore Similan Islands sea temperature in January, including swim comfort and month comparisons →
Similan Islands in February
Typical February water temperature near Similan Islands is 29.2°C (84.6°F), with yearly monthly means from 29.0–29.3°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: January 28.9°C · March 29.9°C.
Explore Similan Islands sea temperature in February, including swim comfort and month comparisons →
Similan Islands in March
Typical March water temperature near Similan Islands is 29.9°C (85.8°F), with yearly monthly means from 29.4–30.3°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: February 29.2°C · April 30.6°C.
Explore Similan Islands sea temperature in March, including swim comfort and month comparisons →
Similan Islands in April
Typical April water temperature near Similan Islands is 30.6°C (87.1°F), with yearly monthly means from 30.2–31.2°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: March 29.9°C · May 30.8°C.
Explore Similan Islands sea temperature in April, including swim comfort and month comparisons →
Similan Islands in May
Typical May water temperature near Similan Islands is 30.8°C (87.4°F), with yearly monthly means from 30.1–31.5°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: April 30.6°C · June 29.8°C.
Explore Similan Islands sea temperature in May, including swim comfort and month comparisons →
Similan Islands in June
Typical June water temperature near Similan Islands is 29.8°C (85.6°F), with yearly monthly means from 29.5–30.3°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: May 30.8°C · July 29.3°C.
Explore Similan Islands sea temperature in June, including swim comfort and month comparisons →
Similan Islands in July
Typical July water temperature near Similan Islands is 29.3°C (84.7°F), with yearly monthly means from 29.0–29.6°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: June 29.8°C · August 29.4°C.
Explore Similan Islands sea temperature in July, including swim comfort and month comparisons →
Similan Islands in August
Typical August water temperature near Similan Islands is 29.4°C (84.9°F), with yearly monthly means from 29.1–29.8°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: July 29.3°C · September 28.8°C.
Explore Similan Islands sea temperature in August, including swim comfort and month comparisons →
Similan Islands in September
Typical September water temperature near Similan Islands is 28.8°C (83.8°F), with yearly monthly means from 28.6–29.0°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: August 29.4°C · October 29.2°C.
Explore Similan Islands sea temperature in September, including swim comfort and month comparisons →
Similan Islands in October
Typical October water temperature near Similan Islands is 29.2°C (84.6°F), with yearly monthly means from 28.8–29.6°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: September 28.8°C · November 29.3°C.
Explore Similan Islands sea temperature in October, including swim comfort and month comparisons →
Similan Islands in November
Typical November water temperature near Similan Islands is 29.3°C (84.7°F), with yearly monthly means from 28.8–29.7°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: October 29.2°C · December 28.9°C.
Explore Similan Islands sea temperature in November, including swim comfort and month comparisons →
Similan Islands in December
Typical December water temperature near Similan Islands is 28.9°C (84.0°F), with yearly monthly means from 28.7–29.3°C.
Swimming and snorkeling: very warm water. Swimwear is usually enough; a rash guard adds sun protection.
Adjacent months: November 29.3°C · January 28.9°C.
Explore Similan Islands sea temperature in December, including swim comfort and month comparisons →
Forecast archive (growing)
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| Month | Min | Average | Max |
|---|---|---|---|
| June | 29.0°C / 84.2°F | 29.6°C / 85.2°F | 30.4°C / 86.7°F |
| July | 29.1°C / 84.4°F | 29.5°C / 85.0°F | 29.9°C / 85.8°F |
| August | 28.9°C / 84.0°F | 29.2°C / 84.5°F | 29.7°C / 85.5°F |
| September | 28.5°C / 83.3°F | 29.0°C / 84.2°F | 29.6°C / 85.3°F |
| October | 29.2°C / 84.6°F | 29.9°C / 85.8°F | 30.8°C / 87.4°F |
| November | 29.6°C / 85.3°F | 30.2°C / 86.4°F | 30.6°C / 87.1°F |
Partial coverage: 6 calendar months with records. Profile calculated from 3814 hourly forecast records across 6 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Similan Islands
Andaman archipelago marine park with granite boulders and crystal-clear reefs.
- Area
- Phang Nga
Similan Islands Water Temperature: Common Questions
What is the water temperature in Similan Islands today?
The current sea surface temperature near Similan Islands is 30.6°C (87.1°F). Over the last 30 days, the average has been 30.0°C.
When is the water warmest in Similan Islands?
The water is typically warmest in May, at around 30.8°C (87.4°F) in the 2022–2025 historical baseline.
When is the water coldest in Similan Islands?
The water is typically coldest in September, at around 28.8°C (83.8°F) in the same historical baseline.
Can you swim in Similan Islands today?
At 30.6°C, the water is usually comfortable for swimming and snorkeling.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Similan Islands.
View Snorkel Forecast →