Smoke Shrouds Northern Thailand

Earth Observatory 

3 min read

Smoke Shrouds Northern ThailandImage of the Day for April 23, 2026

Seasonal fires have darkened skies over Southeast Asia.

NASA Earth Observatory

Apr 23, 2026 Article

View more Images of the Day:Apr 22, 2026Instruments:

• Terra — MODIS

Collections:

• Air Quality

Topics:

• Earth's Atmosphere
• Human Dimensions
• Wildfires

The MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA's Terra satellite captured this hazy view of the city and the surrounding region on April 22, 2026.NASA Earth Observatory/Lauren Dauphin

Chiang Mai, Thailand’s second-largest city, lies within a network of narrow valleys in the country's northern highlands. Though the historic city is known for panoramic views of the surrounding mountains, clear skies have become less common. In recent decades, smoke has increasingly darkened the skies during the dry season, particularly in March and April.

A NASA satellite captured this smoky view of the city and the surrounding region on April 22, 2026, when haze partially obscured valleys and ridges typically visible under clearer conditions. Most of the smoke likely comes from small agricultural and forest fires lit to burn off crop debris or maintain forest ecosystems. In 2026, satellite sensors detected small numbers of fires throughout January, but fire detections became more numerous and widespread in February, March, and April. Fire activity typically peaks in March and fades by May as seasonal rains increase. 

Research indicates that smoke from biomass burning is one of the