Local Weather Context
Bangkok sits in the Chao Phraya River delta, one of Southeast Asia's most flood-prone urban areas. The city's low elevation and dense canal network mean even moderate rainfall can cause street-level flooding within minutes. Real-time radar helps residents and commuters anticipate waterlogged roads before they become impassable.
Seasons
Wet season (May–October)
Southwest monsoon brings intense afternoon thunderstorms, often starting around 14:00–16:00. Monthly rainfall peaks above 300 mm in September. Flash flooding on Sukhumvit, Lat Phrao, and other low-lying roads is common after heavy downpours.
Local Weather Context
Chiang Mai lies in a mountain basin surrounded by Doi Suthep and the Thanon Thong Chai Range. This topography creates unique weather patterns: orographic lift drives heavy rainfall on western slopes, whilst the city basin can trap moisture and pollution. Storms often develop along ridgelines before descending into the Ping River valley.
Seasons
Wet season (May–October)
Southwest monsoon delivers heavy and sustained rain, with August–September averaging 200–250 mm monthly. Mountain thunderstorms can trigger flash floods along streams feeding the Ping River. The old city's moat area and low-lying Kad Farang district are particularly vulnerable.
Local Weather Context
Chon Buri province stretches along Thailand's Eastern Seaboard, encompassing the resort city of Pattaya, the industrial zone of Laem Chabang, and Si Racha's coastal communities. Sea breezes interact with inland convection to create localised storm patterns that can differ dramatically between the coast and areas just 20 km inland.
Seasons
Wet season (May–October)
Onshore winds bring frequent afternoon and evening storms. Rainfall is heaviest in September–October, often exceeding 250 mm per month. Pattaya's beachfront can see sudden squalls that develop over the Gulf of Thailand.
Local Weather Context
Kanchanaburi is Thailand's third-largest province, stretching from the Central Plains deep into the Tenasserim Hills along the Myanmar border. The Kwai Yai and Kwai Noi rivers converge at Kanchanaburi city before flowing into the Mae Klong River. The rugged western mountains catch heavy monsoon rainfall that feeds the strategically important Vajiralongkorn (Khao Laem) and Srinagarind dams.
Seasons
Wet season (May–October)
The southwest monsoon delivers heavy rain, especially to western mountain areas receiving over 2,000 mm annually. Lowland areas around the city average 150–200 mm per month during peak monsoon. Flash flooding along the Kwai rivers and mountain streams can be sudden and dangerous.
Local Weather Context
Khon Kaen is the commercial and educational hub of central Isan, situated on the Khorat Plateau at about 170 m elevation. The Chi River runs through the province, and its flat terrain makes it susceptible to widespread flooding when heavy rains saturate the clay-heavy soil. As Isan's largest city, weather disruptions affect a population of over 400,000.
Seasons
Wet season (May–October)
The southwest monsoon brings 80% of annual rainfall. July–September are the wettest months, with averages of 200–270 mm. Afternoon convective storms are common, sometimes developing into severe thunderstorms with hail over the open plateau.
Local Weather Context
Nakhon Ratchasima (Korat), the gateway to Isan, sits on Thailand's northeastern plateau at around 200 m elevation. The Dong Phaya Yen mountain range to the west creates a rain shadow effect, but when monsoon moisture pushes through the passes, storms can be intense. The flat terrain allows storm cells to travel long distances with little disruption.
Seasons
Wet season (May–October)
Southwest monsoon brings the majority of annual rainfall. August–September are the wettest months, averaging 200–250 mm. Thunderstorms often develop in the afternoon over the plateau, sometimes producing damaging winds and hail.
Local Weather Context
Nakhon Sawan sits at the confluence of the Ping, Wang, Yom, and Nan rivers — the birthplace of the Chao Phraya, Thailand's most important waterway. This strategic location means rainfall here directly affects water levels downstream to Bangkok. The city is a critical flood monitoring point for the entire Central Plains.
Seasons
Wet season (May–October)
Monsoon rainfall combines with runoff from four major rivers. September–October are critical flooding months — the 2011 floods that devastated Bangkok originated in this watershed. Monthly rainfall averages 200–250 mm during peak months.
Local Weather Context
Phuket is Thailand's largest island, exposed to the Andaman Sea on its western coast. The island's weather is governed by two monsoons: the southwest monsoon brings heavy rain and rough seas from May to October, whilst the northeast monsoon (November–April) delivers the dry season that drives peak tourism. Storms approach from the Andaman Sea with little warning due to the open ocean fetch.
Seasons
Wet season (May–October)
Southwest monsoon drives sustained heavy rainfall, often exceeding 300 mm per month from August–October. Western beaches (Patong, Kata, Karon) face large swells and dangerous rip currents. Afternoon storms are near-daily occurrences, sometimes lasting several hours.
Local Weather Context
Prachuap Khiri Khan province occupies Thailand's narrowest point — just 13 km between the Gulf of Thailand and the Myanmar border. This unique geography means weather systems from both the Gulf and the Andaman side can affect the province. Hua Hin, the royal beach resort, and Prachuap city sit directly on the Gulf coast with mountains rising sharply behind them.
Seasons
Wet season (May–November)
Both monsoons affect this narrow isthmus. The southwest monsoon (May–October) brings rain from the Andaman side over the mountains, whilst the northeast monsoon onset (October–November) adds Gulf moisture. September–November can see 200+ mm per month.
Local Weather Context
Surat Thani province spans from the Gulf of Thailand coastline to rainforest mountains inland, including the gateway to Koh Samui, Koh Phangan, and Koh Tao. The province's weather is uniquely influenced by the Gulf monsoon pattern — its wet season peaks later than western Thailand, running through November–January when other regions are dry.
Seasons
Wet season (October–January)
The northeast monsoon drives moisture from the Gulf of Thailand inland. November is the wettest month, often exceeding 400 mm. Severe flooding hit Surat Thani city and surrounding areas in multiple recent years. Koh Samui can receive its entire monthly rainfall in a single storm event.
