Pacific Decadal Oscillation

climatology

Also known as: PDO, PDV, Pacific Decadal Variability

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 17, 2026

Quick Summary

The Pacific Decadal Oscillation (PDO) is a pattern of ocean-atmosphere interaction that influences climate over decades. It involves changes in sea surface temperatures in the North Pacific Ocean. These temperature shifts affect the Aleutian Low, a pressure system that, in turn, impacts precipitation patterns along North America's Pacific Coast.1

The PDO has two phases:
* Cool phase: Coastal Alaska is drier, and the Pacific Northwest is wetter.1
* Warm phase: Coastal Alaska experiences higher precipitation, while the Pacific Northwest is drier.1

Records spanning at least four centuries document these variations. The PDO is one of several decadal climate variations, including the Atlantic Multidecadal Oscillation (AMO), that are subjects of intense study by climatologists.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

4 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

climate change
Decadal variation
One such variation is the Pacific Decadal Oscillation (PDO), also referred to as the Pacific Decadal Variability (PDV), which involves changing sea surface temperatures (SSTs) in the North Pacific Ocean. The SSTs influence the strength and position of the Aleutian Low, which in turn strongly affects precipitation patterns along the…
Read More
One such variation is the Pacific Decadal Oscillation (PDO), also referred to as the Pacific Decadal Variability (PDV), which involves changing sea surface temperatures (SSTs) in the North Pacific Ocean. The SSTs influence the strength and position of the Aleutian Low, which in turn strongly affects precipitation patterns along the…
Read More