El Nino Watch

NASA POWER vs ERA5 cross-check

How closely NASA POWER and Open-Meteo ERA5 agree for Samui, day by day.

Forecasts and bulletins

For the days both have, the mean difference and mean absolute difference of daily maximum and minimum temperature and rain between NASA POWER and ERA5.

Limits. Both are coarse models; neither is a rain gauge on the island.

How to read it

Small mean differences (under 1 degC) mean the two reanalyses agree. On 2026-09-24: max temperature +0.6 degC on average over 55 days; rain POWER 290 mm vs ERA5 189 mm.

Why it matters for Koh Samui

When two independent sources agree, a drought or heat signal is more trustworthy.

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)