El Nino Watch

River level stations (% of bank height)

ThaiWater river gauges, shown as a percentage of the bank height: 100% means the water has reached the top of the bank, more than 100% means it overflows.

Hazards

About 800 ThaiWater river and canal stations report their water level. The percentage is the water depth above the station's ground level, divided by the height of the lower bank at that point (for example Lam Takhong: water at 351.97 m, ground 344.19 m, bank 348.40 m = 184.7%). It is a direct measure of how close a river is to flooding the land around it.

ThaiWater's own scale: over 100% overflow, over 70% high, over 30% normal, over 10% low, 10% or less critically low. The map draws only stations at 80% or more.

How to read it

Square icons with a gauge. Click one for the station, the percentage and the time. A river over its bank upstream usually reaches the towns downstream within hours to days.

Why it matters for Koh Samui

In 2011 the Chao Phraya overflow flooded Bangkok for weeks. Rivers over the bank on the routes to Surat Thani or Bangkok can cut roads and railways out of the South.

Thresholds

% of bankMeaningColour
Below 80%Normal to high waterNot drawn
80 to 99%Near the bank: watchOrange
100% or moreAt or over the bank: flooding nearbyRed

Each station popup shows its own percentage and the time of the reading (ICT).

Sources

Related

ENSO status now

ONI (NOAA CPC)
+1.80 °C, JJA 2026 (previous +1.39 °C)
RONI (NOAA CPC)
+1.36 °C, JJA 2026
Nino 3.4 weekly (NOAA CPC / OISST)
+3.0 °C anomaly, week of 16 Sep 2026 (SST 29.6 °C)