Phuket Wassertemperatur, Luftqualität und Dengue nach Monat

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 Januar and the warmest 31.0 °C in Mai, a span of 2.2 degrees around a year-round mean of 29.8 °C.

The coolest sea comes with the monsoon swell and the mixing it brings: Januar at 28.8 °C, and the lowest single month on record is Januar 2023 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.

The latest month on file, August 2026, 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 (Juli 2026 to August 2026) 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 Juli 2026 is claimed.

The shape of the year follows the rain with a lag: the peak month was Juli 2025 with 280 cases and the quietest Dezember 2025 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.

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. Quelle: Open-Meteo Marine API, tägliche Wassertemperatur am Punkt 7.99°N 98.28°E, 2022-12–2026-09. Quelle: Air4Thai, Pollution Control Department – Station Municipal Health Center, Talat Yai, Mueang Phuket, stündliche PM2.5-Werte. Quelle: Department of Disease Control, thailändisches Gesundheitsministerium – Dengue-Lagebericht, Gesundheitsregion 11, Zeile der Provinz Phuket. Retrieved 2026-10-08. 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.