Phang Nga has two seasons: a dry, sunny high season from November to April and a green monsoon season from May to October — the same Andaman-coast calendar as Phuket and Krabi. Here is what each month feels like, how the sea affects Phang Nga Bay and the Similan Islands, when to come — and what to pack.
Phang Nga sits on the Andaman coast directly north of Phuket, in a tropical monsoon climate — hot and humid all year, with daytime temperatures almost always between 24°C and 34°C. What changes is the rain and the sea, on the same calendar as Phuket and Krabi: the dry high season (November–April) brings sunshine, calm water and full access to Phang Nga Bay and the Similan Islands; the green monsoon season (May–October) brings warm downpours, lower prices — and the closure of the Similan and Surin Islands national parks for roughly five months. The single best stretch is December to February; the wettest month is September; the hottest is April. For live rents by area, use the BAANLYY Phang Nga hub.
Temperatures barely shift across the year; the real story is rainfall and sea state. Months marked ★ are the classic dry-season favourites.
| Month | Season | Typical temp | Rain & sea | Verdict |
|---|---|---|---|---|
| January | High / dry | 24–32°C | Very dry, calm sea | ★ Peak — sunniest, least humid |
| February | High / dry | 25–33°C | Dry, calm sea | ★ Peak — arguably the ideal month |
| March | High → hot | 26–34°C | Dry, calm, warming up | ★ Excellent, starting to get hot |
| April | Hot | 27–36°C | Hot & humid, mostly dry, Songkran | Good but very hot; sea still calm |
| May | Green begins | 26–33°C | Monsoon rains arrive, sea roughening | Shoulder — Similan/Surin parks close mid-month |
| June | Green / monsoon | 25–32°C | Frequent showers, rougher sea | Low-season value; island access limited |
| July | Green / monsoon | 25–32°C | Showers with dry spells | Low season; lush, intermittent rain |
| August | Green / monsoon | 25–32°C | Wet, rougher Andaman sea | Low season; rain often in bursts |
| September | Green / wettest | 25–31°C | Wettest month, strong swells | Quietest & cheapest, most rain |
| October | Green easing | 25–31°C | Wet early, easing late | Transitional; Similan/Surin reopen mid-month |
| November | Dry returns | 25–32°C | Drying out, sea calming | Shoulder — great value, improving fast |
| December | High / dry | 24–31°C | Dry, calm, festive | ★ Peak — busy & beautiful |
Guide figures; weather varies year to year and the monsoon can arrive early or linger.
The dry / high season (Nov–Apr) is driven by the northeast monsoon, keeping Phang Nga dry and sunny — peak months for touring Phang Nga Bay, James Bond Island and the Similan and Surin Islands, with the calmest seas of the year. March and especially April heat up sharply ahead of the rains, with April the hottest month and the Songkran water festival mid-month. The green / monsoon season (May–Oct) is driven by the southwest monsoon: warm, heavy showers that often pass in bursts, dramatic skies, the lushest landscapes and the lowest prices, but also the most significant seasonal disruption of any Andaman province — the Similan and Surin Islands close entirely. September is typically the wettest month, and October can stay wet before clearing late.
This is the section that matters most for anyone planning Phang Nga's signature boat trips and islands.
The Andaman Sea is generally calm and clear along the Phang Nga coast during these months, and this is when Phang Nga Bay's limestone karsts, James Bond Island, Koh Panyi and the Similan and Surin island chains are all at their best and most accessible by longtail and speedboat.
The southwest monsoon brings swells, wind and rougher water. Most significantly for Phang Nga, the Similan Islands and Surin Islands national parks close to all visitors for roughly five months each year, typically mid-May to mid-October, both to protect the marine ecosystem from monsoon-season damage and because sea conditions make the crossing genuinely unsafe. Phang Nga Bay's more sheltered, mangrove-lined waters around Koh Panyi and James Bond Island stay more accessible than the exposed open-sea Similan/Surin routes, but tours still slow down and can be cancelled in the worst weather.
Phang Nga Bay itself is a large, largely enclosed limestone-karst bay and stays comparatively calmer year-round than the fully exposed Andaman further out — it's the open-water crossings to the Similan and Surin Islands, and to a lesser extent Khao Lak's beaches, that the monsoon affects most.
If a Similan or Surin Islands trip is a must-do, build your visit around the November–April window — outside those months the parks are simply not open, regardless of how calm any individual day looks.
For sun, calm seas and full access to every island, target December–February; for the best balance of good weather and value, the shoulder months of November and April are hard to beat. If you are relocating rather than holidaying, the green season often brings softer short-term rents and far less competition for the best units.
| When | What to pack |
|---|---|
| Year-round | Light, breathable clothing, strong sun protection, a hat and sunglasses, reef-safe sunscreen, and good sandals or reef shoes for rocky beaches and boat landings — it is hot and humid in every month. |
| Dry / high season | Add a light layer for air-conditioned spaces and cooler December–January evenings; book Similan/Surin tours, Phang Nga Bay cruises and accommodation early, as this is peak demand across the Andaman coast. |
| Green / monsoon season | Pack a compact umbrella or rain shell, quick-dry footwear, and a dry bag for electronics on boat trips; remember the Similan and Surin Islands are simply closed for most of this window, so plan Andaman island-hopping around Phang Nga Bay's more sheltered routes instead. |
Because the whole province shares one climate, the weather questions that matter for renters are local: drainage, elevation and exposure to the open coast versus the more sheltered bay side. Year-round heat also makes air-conditioning efficiency and cross-breeze worth checking when you view a condo or villa — it directly shapes your electricity bill. Explore the trade-offs area by area on the Phang Nga hub, and model seasonal costs with the Phang Nga cost-of-living guide.
November to April is Phang Nga's dry high season, with the sunniest skies, the calmest Andaman Sea and full access to Phang Nga Bay, the Similan Islands and the Surin Islands. The sweet spot is December to February, when humidity is lowest and evenings are pleasantly cooler. March is excellent but warming up, and April is hot.
The green or monsoon season runs roughly May to October, driven by the southwest monsoon. September is typically the wettest month, and October can stay wet before clearing late in the month. Rain often falls in heavy bursts rather than all day, and the province is at its lushest, cheapest and quietest during this window.
No. The Similan Islands National Park and the neighbouring Surin Islands National Park close to all visitors for roughly five months each year, typically from mid-May to mid-October (exact dates are set annually by Thailand's National Parks department), to protect the marine ecosystem from monsoon damage and because open-sea crossings become genuinely unsafe in that window. If a Similan or Surin trip is a priority, plan your visit for November through April.
April is typically the hottest month, with daytime highs around 34–36°C ahead of the rains, often coinciding with the Songkran water festival. September is usually the wettest month, when the southwest monsoon peaks. January and February are the driest and most comfortable months of the year.
Often yes, with more caveats than in the dry season. Phang Nga Bay is a largely sheltered, mangrove-lined limestone-karst bay, so it holds up better in rough weather than the fully exposed open-sea routes to the Similan and Surin Islands, which are simply closed for most of the monsoon. Even in the bay, tours can slow down or pause in the worst storms, so always check conditions and never pressure a boat operator to sail in dangerous seas.
Somewhat. The whole province shares the same monsoon pattern, so the bigger local questions are drainage, elevation and exposure to the open coast versus the more sheltered bay side. Supply is thinner and more seasonal than in Phuket, so securing a long lease before high season is worth doing early. Each BAANLYY Phang Nga area guide notes the local feel, and the cost-of-living guide covers seasonal pricing.
Primary and official sources are cited above. Government rules, fees and procedures in Thailand change over time and vary by office; always confirm current requirements with the relevant authority before relying on them. BAANLYY never takes paid placement in editorial content.
Whether you come for the dry-season sun or the green-season value, match the right Phang Nga area and home to how you want to live.
Hero photo by Laura Meinhardt on Pexels.