CHIANG RAI – The Department of Disaster Prevention and Mitigation (DDPM) and Mae Sai authorities are closely monitoring the water levels in the Sai River. The current situation at the Friendship Bridge 1 station shows water is nearly at the top, with levels expected to keep rising.
People living in low-lying areas along the Sai River should stay alert to the risk of possible flooding. This includes residents in:
- Sailomjoy Community, Moo 1, Wiang Pang Kham Subdistrict
- Koh Sai Community, Moo 7, Mae Sai Subdistrict
- Mai Lung Khan Community, Mae Sai Subdistrict
- Muang Daeng Community, Mae Sai Subdistrict
Take extra care of those who may need help, such as elderly people and those with limited mobility. Keep up to date with updates and guidance from your local officials.
The Department of Disaster Prevention and Mitigation DDPM has teamed up with mobile providers AIS, True, and NT to send out flood alerts for the Sai River area using the Cell Broadcast system.
Mae Sai communities at higher risk include:
- Sailomjoy Community, Moo 1, Wiang Pang Kham Subdistrict, Mae Sai District, Chiang Rai
- Koh Sai Community, Moo 7, Mae Sai Subdistrict, Mae Sai District, Chiang Rai
- Mai Lung Khan Community, Moo 10, Mae Sai Subdistrict, Mae Sai District, Chiang Rai
- Muang Daeng Community, Moo 2, Mae Sai Subdistrict, Mae Sai District, Chiang Rai
If you need help or want to report an emergency, you can use the “แจ้ง 1784” LINE channel or add @1784DDPM on LINE. You can also call the 1784 emergency hotline at any time, day or night.
Weather Forecast for Chiang Rai Province, September 24–26, 2025
Chiang Rai Province in northern Thailand is in its rainy season during late September, characterized by warm temperatures, high humidity, and frequent showers or thunderstorms.
Expect daytime highs around 28–30°C (82–86°F) and nighttime lows around 23–24°C (73–75°F), with a high chance of precipitation (over 80% daily) and total rainfall potentially exceeding 30mm over the period. Winds will be light (5–15 km/h, southerly). These conditions are typical for the region, but always check local updates closer to the date for any tropical storm influences.
Province-Wide Summary (Based on Mueang Chiang Rai Area)
| Date | High/Low (°C) | Conditions | Precipitation Chance | Rainfall (mm) | Wind |
|---|---|---|---|---|---|
| Sept 24 (Wed) | 29/23 | Thunderstorms, humid | 90% | ~19 (PM heavy) | Light S, 5–10 km/h |
| Sept 25 (Thu) | 29/23 | Scattered thunderstorms | 80% | ~3 (AM) | Light S, 5–10 km/h |
| Sept 26 (Fri) | 25/22 | Heavy rain, cooling trend | 95% | ~15 (AM heavy) | Light S, 10 km/h |
Mae Sai District (Northern Border Area)
Mae Sai, located in the northern tip of Chiang Rai Province near the Myanmar border, often experiences slightly cooler and heavy rain conditions due to its higher elevation (~400m) and topography. Temperatures will mirror the province, but with potentially more persistent rain. Highs around 28–29°C (82–84°F), lows 23–22°C (73–72°F), humidity 85–95%, and winds light (5–10 km/h, variable)
| Date | High/Low (°C) | Conditions | Precipitation Chance | Rainfall (mm) | Wind |
|---|---|---|---|---|---|
| Sept 24 (Wed) | 28/23 | Thunderstorm AM, moderate rain PM | 85% | ~12 (PM heavy) | Light W, 5 km/h |
| Sept 25 (Thu) | 29/23 | Thunderstorms all day, heavy at night | 90% | ~12 (Night) | Light S, 5–10 km/h |
| Sept 26 (Fri) | 24/22 | Heavy rain AM, thunderstorms PM | 95% | ~14 (AM heavy) | Light S, 10 km/h |
Typhoon Ragasa Impact (September 23-26, 2025): The typhoon is bringing heavy to very heavy rain (up to 100-150 mm/day in northern areas), increasing flood risks in Chiang Rai. Seas in the upper Gulf of Thailand are rough (2-3 meter waves), but this indirectly affects river levels through sustained rainfall.
The Sai River has overflowed multiple times in 2025 (e.g., May, July) and 2024, flooding border markets like Sai Lom Joy and communities such as Ban Koh Sai and Ban Mai Lung. Past events highlight vulnerabilities like embankment leaks and transboundary dredging delays from Myanmar. Residents in Mae Sai have expressed fears of repeats, with ongoing reinforcements to flood barriers.
