WMO's work addresses many thematic areas. Each thematic page below provides accessible information: a definition, the impact and an introduction to WMO's work in each area. Across the website, we link back to these pages as references.

Main themes

Large thunderstorm cloud illuminated by lightning over the ocean at night, with stars visible in the sky and a small coastal area lit on the right side.

Weather
Dense forest with tall trees in the foreground, covered in morning mist, under a bright orange sunrise sky.

Climate
A child in a pink shirt and striped shorts rinses their face with water from an outdoor faucet on a sunny day.

Water

Natural hazards

Cracked, dry ground stretches toward a distant water reservoir, with hills and a clear blue sky in the background.

Drought
Heatwave on the city with the glowing sun background

Extreme Heat
Person in shorts wades through knee-deep water, pushing a bicycle. The lower part of the bike and legs are partially submerged.

Floods
A huge cloud of sand blows over a city.

Sand and dust storms
Satellite view of a large, swirling hurricane over the ocean near a continent, with a clear eye at the center and surrounding cloud bands.

Tropical cyclone

Wildfires

Sectors

Drone in storm over roiling waters

Artificial intelligence

flying above the clouds watching the landscape

Aviation
Image shows solar panels, wind mills and a power grid against a blu sky with small clouds

Energy
People ride motorbikes across a rusty metal bridge in an urban area, with buildings visible on the right and a sidewalk running alongside the road.

Health

Earth System domains

Nepal's mount everest at sunset.

Cryosphere
Image of a satellite in orbit around the Earth

Earth observation satellites
Panoramic view of a glacier winding between rugged mountains under a blue sky with scattered clouds. Rocky foreground leads to the expansive ice flow, surrounded by green slopes and rocky peaks.

Glaciers and Ice Caps
Aerial view of ocean waves with white foam and deep blue water.

Ocean
Ice floes floating on a vast ocean under a clear blue sky, showcasing a polar seascape.

Sea Ice
Snow-covered mountain landscape under a blue sky with scattered clouds, featuring two prominent peaks and soft shadows on the snow.

Snow
Stratospheric Ozone

The Ozone Layer

Atmospheric phenomena

Silver Lining on the ocean

El Niño / La Niña Phenomena
Smoke rises from a power plant at sunset.

Greenhouse gases
Last updated: 17 September 2026