Characteristic of the Regional Rainy Season Onset over Vietnam: Tailoring to Agricultural Application

Owing to its unique position within multiple monsoon regimes, latitudinal extent, and complex topography, Vietnam is divided into seven agroclimatic zones, each with distinct rainy season characteristics. Variation in the dominant rainfall system across zones affects climatology, primary water resource for regional crops. This study explores creation of an agronomic onset based on high-resolution data zone applications agricultural context. Onset information has huge practical importance both agriculture economy. The spatiotemporal characteristics zonal date are analyzed using integrated approaches spatial interannual variability, temporal changes, estimation predictability teleconnection Niño 3.4 sea surface temperature anomalies (SSTA) 1980 2010. Results suggest that northern southern experience dates May, while central late August. variability lower higher which latitudinally extended. variation found be approximately two weeks all zones. significant negative trend Central Coast South suggesting shifted earlier entire period. In decadal scale, mean later Northwest Highlands. Out climate a positive correlation only noticed Highlands between SSTA Dec–Jan–Feb, potential seasonal scale respect preceding El Niño-Southern Oscillation (ENSO) events.