Dominant Climate of Indochina: Tropical Monsoon Explained

The Indochinese Peninsula—comprising Vietnam, Laos, Cambodia, Thailand, and Myanmar—experiences a classic tropical monsoon climate. This climate is defined by two sharply contrasting seasons driven by seasonal wind reversals.

Wet Season (May – October)

Southwest monsoon winds bring abundant moisture from the Indian Ocean and the South China Sea. Rainfall is heavy and frequent, with monthly totals often exceeding 200 mm. Temperatures remain warm, averaging 27–30 °C (81–86 °F), and humidity is high.

Dry Season (November – April)

Northeast monsoon winds deliver cooler, drier air from the Asian interior. Rainfall drops dramatically, skies clear, and temperatures can be slightly lower, especially in northern areas where night-time lows may dip below 20 °C (68 °F).

Key Statistics

• Average annual temperature: ~27 °C (80.6 °F)
• Average annual rainfall: ~1,500 mm (59 in)

These patterns shape agriculture, water resources, and daily life across the region, making the monsoon cycle the single most influential climatic feature of Indochina.