What is the sea temperature in Phuket by month?
Between 28.8 °C in 一月 and 31.0 °C in 五月 as a monthly normal (median of 2022–2026, Open-Meteo Marine API at 7.99°N 98.28°E). Every month of the year is above 28 °C; the year-round mean is 29.7 °C.
普吉岛逐月海水温度、空气质量与登革热
西海岸外安达曼海每月有多暖、普吉镇 PM2.5 监测站记录到什么、全府每周通报多少登革热病例——三组旅行者切身感受得到的环境数据，全部转录自公开来源，绝不估算。
来源：Open-Meteo Marine API，7.99°N 98.28°E 点位逐日海面温度，2022-12–2026-08. 统计 · 最佳旅行时间 · 全部来源
29.9 °C
海水温度，2026年8月
五月 · 31.0 °C
最暖海水（常年值）
一月 · 28.8 °C
最凉海水（常年值）
11.3 µg/m³
PM2.5，2026年8月
0 / 62
超过泰国 24 小时标准的天数
1,546
登革热病例，2025
按月份的海面温度，°C（2022–2026 中位数）
| 月份 | 均值，°C | 最凉一天 | 最暖一天 | n 年 |
|---|---|---|---|---|
| 一月 | 28.8 | 28.2 | 29.5 | 3 |
| 二月 | 29.1 | 28.5 | 30.1 | 3 |
| 三月 | 29.8 | 28.6 | 31.1 | 4 |
| 四月 | 30.7 | 28.6 | 32.2 | 4 |
| 五月 | 31.0 | 29.6 | 32.3 | 4 |
| 六月 | 30.1 | 29.3 | 31.8 | 4 |
| 七月 | 29.9 | 29.2 | 31.0 | 4 |
| 八月 | 29.9 | 29.1 | 31.2 | 4 |
| 九月 | 29.2 | 28.4 | 30.3 | 3 |
| 十月 | 29.5 | 28.7 | 30.6 | 3 |
| 十一月 | 29.8 | 28.5 | 30.8 | 3 |
| 十二月 | 29.0 | 28.2 | 30.0 | 4 |
均值，°C: median of the monthly means over the years on file; 最凉一天 / 最暖一天: extreme daily values seen in that calendar month, any year. The warmest month is marked. 来源：Open-Meteo Marine API，7.99°N 98.28°E 点位逐日海面温度，2022-12–2026-08.
海面温度，最近 24 个月，°C
均值，°C常年值
| 月份 | 均值，°C | 最凉一天 | 最暖一天 | 常年值 | Δ |
|---|---|---|---|---|---|
| 2026年8月 | 29.9 | 29.5 | 30.5 | 29.9 | 0.0 |
| 2026年7月 | 30.1 | 29.7 | 30.7 | 29.9 | +0.2 |
| 2026年6月 | 30.0 | 29.3 | 30.7 | 30.1 | -0.1 |
| 2026年5月 | 31.1 | 29.8 | 32.2 | 31.0 | +0.1 |
| 2026年4月 | 30.9 | 30.2 | 32.0 | 30.7 | +0.2 |
| 2026年3月 | 29.6 | 28.6 | 30.7 | 29.8 | -0.2 |
| 2026年2月 | 29.1 | 28.7 | 29.8 | 29.1 | 0.0 |
| 2026年1月 | 28.8 | 28.5 | 29.4 | 28.8 | 0.0 |
| 2025年12月 | 28.9 | 28.5 | 29.3 | 29.0 | -0.1 |
| 2025年11月 | 28.9 | 28.5 | 29.6 | 29.8 | -0.9 |
| 2025年10月 | 29.2 | 28.7 | 29.9 | 29.5 | -0.3 |
| 2025年9月 | 29.0 | 28.6 | 29.5 | 29.2 | -0.2 |
| 2025年8月 | 29.8 | 29.2 | 30.4 | 29.9 | -0.1 |
| 2025年7月 | 29.7 | 29.5 | 30.1 | 29.9 | -0.2 |
| 2025年6月 | 29.8 | 29.3 | 30.4 | 30.1 | -0.3 |
| 2025年5月 | 30.2 | 29.6 | 31.5 | 31.0 | -0.8 |
| 2025年4月 | 30.5 | 29.9 | 31.5 | 30.7 | -0.2 |
| 2025年3月 | 30.0 | 29.3 | 30.6 | 29.8 | +0.2 |
| 2024年12月 | 29.4 | 29.1 | 30.0 | 29.0 | +0.4 |
| 2024年11月 | 29.8 | 29.1 | 30.6 | 29.8 | 0.0 |
| 2024年10月 | 29.8 | 29.1 | 30.5 | 29.5 | +0.3 |
| 2024年9月 | 29.2 | 28.4 | 30.1 | 29.2 | 0.0 |
| 2024年8月 | 30.6 | 29.7 | 31.2 | 29.9 | +0.7 |
| 2024年7月 | 30.4 | 30.0 | 31.0 | 29.9 | +0.5 |
Δ: month minus its normal, °C. Newest first. 来源：Open-Meteo Marine API，7.99°N 98.28°E 点位逐日海面温度，2022-12–2026-08.
逐月 PM2.5，µg/m³
| 月份 | 月均值 | 最差一天 | 天数 > 37.5 | 天数 > 15 | 监测天数 |
|---|---|---|---|---|---|
| 2026年8月 | 11.3 | 26.8 | 0 | 6 | 31 |
| 2026年7月 | 8.7 | 16.2 | 0 | 1 | 31 |
µg/m³; 天数 > 37.5: daily means above Thailand's 24-hour standard (37.5 µg/m³); 天数 > 15: above the WHO 2021 guideline (15 µg/m³). 来源：Air4Thai，泰国污染控制厅——Municipal Health Center, Talat Yai, Mueang Phuket 监测站，逐小时 PM2.5.
逐月登革热病例，2025
| 月份 | 病例 | 死亡 | 周数 |
|---|---|---|---|
| 2025年1月 | 152 | 0 | 5 |
| 2025年2月 | 68 | 0 | 4 |
| 2025年3月 | 45 | 0 | 4 |
| 2025年4月 | 100 | 0 | 5 |
| 2025年5月 | 140 | 0 | 4 |
| 2025年6月 | 278 | 1 | 4 |
| 2025年7月 | 280 | 0 | 5 |
| 2025年8月 | 142 | 0 | 4 |
| 2025年9月 | 98 | 0 | 4 |
| 2025年10月 | 101 | 0 | 5 |
| 2025年11月 | 101 | 0 | 4 |
| 2025年12月 | 41 | 0 | 5 |
approximation — each epi week counted in the month that contains its Wednesday. The peak month is marked. 来源：泰国公共卫生部疾病控制厅——登革热疫情报告，第 11 卫生区，普吉府一行.
What the sea temperature series measures
The sea-surface temperature on this page is the Open-Meteo Marine API's daily value at 7.99°N 98.28°E, a point in the Andaman Sea a few kilometres off the west coast between 邦涛 and 拉扬. The marine archive carries the variable for this point from 2022-11-24, so the first complete month is 2022年12月 and the file runs to 2026年8月 — 43 complete months over 2022–2026. Each month stores three numbers: the mean of the daily means, the lowest daily minimum and the highest daily maximum. A month is written only when every day has a value; 2025年1月 and 2025年2月 are missing from the archive and stay empty here rather than being filled from neighbours. The normals table is the median of the monthly means over the 4 years on file for each calendar month — a short record compared with the eleven-year land climate normals on the best-time page, and the n column says so for every row.
The Open-Meteo marine product is a model reanalysis of the open sea, not a thermometer on the beach: water inside a shallow bay at noon in April is warmer than the number, the water at the reef after a monsoon upwelling can be cooler. What the series is good for is the shape of the year and the month-to-month comparison, which is stable from year to year, and the honest answer to the question every visitor asks — whether the sea is warm enough to swim in — which for Phuket is yes in every month: the coolest normal on file is 28.8 °C in 一月 and the warmest 31.0 °C in 五月, a span of 2.2 degrees around a year-round mean of 29.7 °C.
Warmest and coolest sea: 五月 against 一月
The Andaman off Phuket is warmest at the end of the dry season, when the north-east monsoon has died and the south-west monsoon has not yet stirred the water: 五月 at 31.0 °C, with 8 of the twelve normals at or above 29.5 °C. The single warmest month on record is 2024年5月 at 31.8 °C; the highest daily maximum in any 五月 on file is 32.3 °C. Those are coral-bleaching temperatures — the 2024 bleaching event on Phuket's reefs coincided with exactly this kind of April–May peak — and the reason the snorkelling trips to Racha and Coral Island are best in the cooler, clearer months rather than in the hottest ones.
The coolest sea comes with the monsoon swell and the mixing it brings: 一月 at 28.8 °C, and the lowest single month on record is 2023年1月 at 28.6 °C. Even that is warmer than a Mediterranean August, which is the point of the comparison for visitors from Europe: there is no month in which the sea temperature argues against a swim; the argument in the green season is the flags on the beach and the rough-sea days on the best-time page, not the temperature. The last-24-months table shows how each month compared with its normal; a monsoon month that runs warm usually means a weak swell and a calmer sea than usual.
Air quality: what the PM2.5 monitor in 普吉镇 records
PM2.5 is fine particulate matter — the pollutant behind the haze seasons of Chiang Mai and Bangkok — and the question travellers ask about Thailand is whether Phuket has one. The station used here is the Pollution Control Department's reference monitor 43t at the Municipal Health Center in Talat Yai, 普吉镇, which is published on the Air4Thai network; the page stores one line per month from its hourly readings: the mean of the daily means, the worst single day, and the number of days above 37.5 µg/m³ (Thailand's 24-hour standard) and above 15 µg/m³ (the WHO 2021 guideline). A day needs at least 18 valid hours to count and a month at least 24 days.
The latest month on file, 2026年8月, averaged 11.3 µg/m³ with a worst day of 26.8 µg/m³, 0 days above the Thai standard and 6 above the WHO guideline. Across the 2 months recorded (2026年7月 to 2026年8月) the mean is 10.0 µg/m³ and 0 of 62 measured days exceeded 37.5 µg/m³. The Air4Thai history service serves only the most recent weeks, so this series began with the site's first collection and grows by one month every refresh; the months that matter most for the haze question — February to April, when smoke from field burning on the mainland and in Sumatra occasionally reaches the island — will appear here as they are recorded, and nothing before 2026年7月 is claimed.
Dengue: 1,546 cases in 2025
Dengue fever is the health risk Phuket actually has, and the one visitors most often ask about after the beach flags. The series is the Department of Disease Control's weekly situation report for Health Region 11, published as open data with one row per district and sub-district and one row for the province; only the province row is used here, so nothing is double-counted. Cases are reports under the R506 surveillance system by epidemiological week — week 1 runs from 1 January to the first Saturday — and the monthly figures assign each week to the month that contains its Wednesday, which is why the month table carries a weeks column. In 2025 Phuket reported 1,546 cases and 1 death over 53 weeks, about 29.2 cases a week for a province of roughly 420,000 registered residents and many more actual ones.
The shape of the year follows the rain with a lag: the peak month was 2025年7月 with 280 cases and the quietest 2025年12月 with 41; 67% of the year's cases fell in May–October, the south-west monsoon months when standing water breeds the Aedes mosquito that carries the virus. The peak week was week 26 with 82 cases. The practical reading for a visitor is about behaviour, not fear: the Aedes mosquito bites by day, in and around houses and gardens rather than on the beach, so repellent at dawn and dusk, screens or air-conditioning at night and no standing water on a villa terrace do most of the work. Dengue is treated in every hospital on the island; the test is quick and the disease is dangerous mainly on a second infection, which is why residents take it more seriously than tourists do. Only 2025 is on file so far: the open-data file publishes the current year, and earlier years will be added from the archived reports as they are located; no historical figure is estimated in the meantime.
Coverage, gaps and updates
Three sources, three cadences. The sea temperature is recomputed for the last three complete months on the 1st and the 8th of every month by the same routine that refreshes the land climate file, so a revised reanalysis month replaces the earlier value; older months are left exactly as committed. PM2.5 is collected on the 5th of every month for the previous month from the Air4Thai hourly service and appended, never revised. The dengue file is re-read on the same day and the current year replaced in full, because the DDC report adds late notifications to earlier weeks. Every figure carries its month or week; where a source has no value the cell is empty, and no month is interpolated.
The three series are free to reuse under CC BY 4.0 with attribution to phukettravels.com and the named sources; the CSV below carries every month with sea temperature (mean, lowest day, warmest day), PM2.5 (monthly mean, days above 37.5 and 15 µg/m³) and dengue cases and deaths. 来源：Open-Meteo Marine API，7.99°N 98.28°E 点位逐日海面温度，2022-12–2026-08. 来源：Air4Thai，泰国污染控制厅——Municipal Health Center, Talat Yai, Mueang Phuket 监测站，逐小时 PM2.5. 来源：泰国公共卫生部疾病控制厅——登革热疫情报告，第 11 卫生区，普吉府一行. Retrieved 2026-09-05. The land climate normals — rain, sunshine, temperature and rough-sea days — are on the best-time page, and every external source with its URL and licence is on the sources page.
常见问题
When is the sea warmest in Phuket?
五月, with a normal of 31.0 °C and daily maxima up to 32.3 °C — the end of the dry season before the south-west monsoon mixes the water. The single warmest month on record is 2024年5月 (31.8 °C).
Is the sea cold in Phuket during the monsoon?
No. The coolest normal is 28.8 °C in 一月, and the lowest single month on record 28.6 °C (2023年1月). What changes in the monsoon is the swell and the red flags, not the temperature.
Does Phuket have a PM2.5 haze season?
The PCD monitor in 普吉镇 recorded a monthly mean of 11.3 µg/m³ in 2026年8月 with 0 days above Thailand's 37.5 µg/m³ standard. Phuket is far from the northern burning season; the months to watch are February–April, and the series on this page grows by one month every refresh so those months will be reported as measured, not assumed.
How many dengue cases does Phuket have (2025)?
1,546 reported cases and 1 death in 2025 over 53 epidemiological weeks (Department of Disease Control, Health Region 11 report), peaking in 2025年7月 with 280 cases; 67% of the year's cases fell in May–October. The Aedes mosquito bites by day; repellent and no standing water are the practical defence.
开放数据
下载逐月海水温度、PM2.5 与登革热数据 CSV · 完整数据集，JSON
CC BY 4.0 — free to use with attribution to phukettravels.com, Open-Meteo Marine API, Air4Thai, Pollution Control Department and the Department of Disease Control, Ministry of Public Health. 全部来源 · 统计 · 燃油、工资与电费 · Monsoon season guide