Island Climatic Types

There are four climatic types of islands in the Grand Line: Winter Islands, Summer Islands, Spring Islands, and Fall Islands. Each of these islands have a climate similar to their namesake seasons. There are still different seasons on each island, with the weather in each season dependent on the type of island. The Red Line is composed of such islands grouped together.

Winter Island
A Winter Island (冬島) is an island with cold climate. On winter islands, snow is normally seen even in the summer.
 * Drum Island
 * Karakuri
 * Yukiryu Island
 * Unnamed island belonging to Kaido (in the New World)

Spring Island
A Spring Island (春島) is blooming with plant life and has nice warm weather.
 * Jaya
 * Unnamed island where the On Air Pirates were last seen (in the New World).

Summer Island
A Summer Island (夏島) has a hot and dry climate.
 * Alabasta

Fall Island
A Fall Island (秋島) has yet to appear in the series, although according to Nico Robin, the island that comes after Alabasta is an Autumn Island.

Special cases

 * The Red Line, according to Nami, is composed of several islands linked together, each with its own climatic zone.
 * Rusukaina is a forty-eight season island whose climate changes every week.
 * Little Garden is a prehistoric island which has an extreme climate and dinosaurs still exist there.

Island Climatic Zones
The climatic type of an island is reflected upon the sea which surrounds the island itself. So, when sailing through the Grand Line the weather becomes stable, then most there is most likely an island in proximity. Between the islands, the weather is inconsistent and unpredictable. A particular case of this phenomenon is the immediate first part of the Grand Line, after Twin Cape, because the influences of the first seven island climatic zones and their magnetic field make the weather chaotic.

Trivia

 * Nami realizes how to "ride" Reverse Mountain when she realized it was a Winter Island. This does not follow because it was Vivi who told them about the different islands and had not yet joined them.