El Nino Watch

ECMWF seasonal outlook maps for Asia

Europe's 3-month rain and temperature outlook maps for Asia, updated monthly.

Data and trust

ECMWF's SEAS5 seasonal model runs 51 times each month. The app keeps its open outlook maps for Asia: rain for the next 4 overlapping 3-month seasons and temperature for the next 2.

Limits. Probabilities, not amounts. Images only (numbers are not open). The Nino plume from ECMWF is a separate source (ecmwf_nino_plume).

How to read it

Each map shows the most likely category vs 1993-2016 and how likely it is. Rain: brown/orange = drier than normal favoured (darker = more likely, up to 70-100 %), green/teal = wetter, white = no clear signal. Temperature: orange/red = warmer, blue = colder. The September 2026 run favours a dry OND 2026 over the Philippines and the South China Sea.

Why it matters for Koh Samui

Samui's main rains fall October-December; a drier outlook there means water shortages later into 2027.

Sources

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)