CHIANG RAI– The summer heat is officially giving way to the rainy season. A powerful southwest monsoon is currently sweeping across the country, prompting national weather experts to urge caution.
According to the latest 7-day outlook from the Thai Meteorological Department , a combination of a strong monsoon over the Andaman Sea and a low-pressure cell near Myanmar will bring steady rainfall to most areas. Heavy downpours are expected to trigger flash floods and sudden forest run-offs, especially in steep or low-lying communities.
Local officials are keeping a close watch on dozens of provinces, advising residents to stay alert to sudden weather changes over the next week.
Severe Weather Alerts and Safety Risks
The national weather bureau has issued a high-priority warning regarding cumulative rainfall. Because the ground is already wet from recent storms, extra rain cannot be absorbed quickly into the soil, significantly increasing the risk of flash flooding near foothills and waterways.
- Flash Flood Warning:Communities located near natural hillsides and lowlands must monitor water levels closely.
- Maritime Danger:Sailors in the Gulf of Thailand and the Andaman Sea should navigate with extreme caution.
- Small Boats Warning:Small vessels operating in the upper Andaman Sea are urged to stay ashore through June 5 due to rough conditions. Waves are expected to rise to 3 meters high during severe thunderstorms.
7-Day Weather Forecast for Chiang Rai
For residents and travelers in Chiang Rai, the upcoming week promises typical wet-season conditions. Daytime temperatures will remain quite warm and muggy, followed by late afternoon or nighttime showers.
- May 31 – June 1:Expect cloudy mornings with isolated thunderstorms rolling in by the late afternoon. Temperatures will peak around 34°C (93°F) during the day, dropping to a comfortable 22°C (72°F) at night.
- June 2 – June 3:The sky will remain mostly overcast. Humidity will hover around 80%, making the air feel much hotter than the actual thermometer reading. Showers are highly likely late in the day.
- June 4 – June 5:A surge in monsoon strength will likely bring more widespread, heavy thunderstorms to the province. Daily highs will drop slightly to 33°C (91°F) due to heavy cloud cover, with a high chance of rainfall across 60% of the area.
- June 6 – June 7:Showers will turn more scattered, appearing primarily in the early morning or late evening. Conditions will remain breezy and humid.
Regional Breakdown Across Thailand
The impact of the southwest monsoon varies slightly by geography, but rain is the common denominator across the country.
Northern and Northeastern Regions
The upper part of Thailand will experience scattered to fairly widespread downpours. Daily high temperatures will range between 31°C and 38°C, while evening lows will sit around 23°C to 27°C. The heaviest rain will hit the western mountain borders.
Central Plains and Bangkok
The Bangkok Metropolitan area and surrounding central provinces face a wet week ahead. Scattered thundershowers are on the schedule daily, with afternoon temperatures hitting a sticky 37°C. The western sections of the central plains will experience the most consistent rainfall.
Eastern and Southern Regions
The eastern coast and the southern peninsula are bearing the brunt of the monsoon winds. Provinces along the Andaman coast—including Phuket and Krabi—face widespread thundershowers and isolated, very heavy downpours. Strong southwesterly winds will keep coastal areas rocky, with rough seas and large waves expected throughout the period.
If you are living in or traveling through Thailand this week, a few simple adjustments will keep you safe. Keep a reliable umbrella or raincoat on hand, and check local road conditions before driving through low-lying areas. If you live near a river or foothill, keep an eye on official updates from your local community leaders.


















