ENSO sensitivity (how much El Nino reaches a place)
How strongly El Nino and La Nina change the weather of each place, assessed from agency and peer-reviewed sources: strong for Samui, weak for Normandy and central Russia.
El Nino basics
El Nino warms the tropical Pacific and moves the big rain-making areas. The effect reaches far-away places through the atmosphere (Teleconnections), strongly near the Pacific and weakly elsewhere.
Maenam (Southeast Asia): strong (3). El Nino usually brings less rain and more heat to the region (Juneng & Tangang 2005). On Samui, a weak north-east monsoon (October-January) leaves the reservoirs low for the dry season: PWA rotated water supply from August 2026.
Saint-Gatien-des-Bois (Normandy): weak (1). The North Atlantic dominates; the ENSO signal in Europe is small and mostly in late winter (Bronnimann 2007). The Met Office notes El Nino is one factor that can raise the risk of colder UK winters.
Gorokhovets (central Russia): weak (1). Far inland; winters are driven by the NAO / Arctic Oscillation and the Siberian High. No agency statement specific to the region was found.
For 2026-27 (a strong El Nino): Samui should prepare for a drier end of monsoon and a long, hot 2027 dry season; for Normandy and Gorokhovets, El Nino says little, so use the ECMWF seasonal anomalies on the page.
Why it matters for Koh Samui
This project exists because of the 2026 El Nino. A place with weak sensitivity is not "safe", it is simply less affected by this particular driver.
Thresholds
Score
Meaning
0
none known
1
weak / indirect
2
moderate
3
strong
4
very strong (Indonesia, coastal Peru, eastern Australia)
--
not assessed (added places outside the curated regions)
Curated, not measured: each region lists its evidence. Exposure scale: 0 very low, 1 low, 2 moderate, 3 high, 4 very high. Higher = more exposed. The colour of the matrix cell follows the same scale.