World Meteorological Day

What Is World Meteorological Day?

Every March 23rd is "World Meteorological Day." It commemorates the entry into force of the World Meteorological Organization (WMO) Convention on March 23, 1950, marking the official founding of the WMO. It's a day to raise awareness about weather, climate, and water resources, and to reaffirm the importance of international cooperation in weather observation, disaster prevention, and environmental conservation. Each year, a global theme is set based on current issues facing the planet, and awareness campaigns are held around the world.

The History of International Cooperation in Weather Observation

Weather doesn't respect borders, so global cooperation is essential.

• The role of the WMO: Headquartered in Geneva, Switzerland, the WMO is a UN specialized agency that coordinates the standardization and real-time sharing of weather data worldwide. This makes it possible to achieve forecast accuracy that no single country could reach on its own.
• Japan and international observation: Japan has been a WMO member since 1953, and through operations like the Himawari geostationary weather satellites, it has continued to play a leading role in weather monitoring across Asia and the western Pacific.

Climate Change and Disaster Prevention: The Scientific Facts

Weather observation data provides the scientific foundation for understanding our planet's present and safeguarding its future.

• Monitoring global warming: Long-term weather data has scientifically confirmed that global average temperatures are rising. The WMO publishes detailed reports on the progress of climate change, including greenhouse gas concentrations, sea level rise, and glacier melt.
• The importance of early warning systems: Early warning systems based on accurate weather forecasting are among the most effective tools for minimizing the damage caused by natural disasters. The WMO has set a goal of "Early Warnings for All," supporting developing countries in strengthening their disaster preparedness.

Interesting Facts About Weather

• Himawari's view: The Himawari weather satellite watches over Earth from about 36,000km above. By observing multiple wavelengths, including infrared, it can track cloud movement and sea surface temperature even at night.
• AMeDAS's dense network: Japan's AMeDAS (Automated Meteorological Data Acquisition System) consists of around 1,300 stations nationwide, spaced an average of about 17km apart—an extremely dense observation network that helps catch localized heavy rain early.
• Supercomputer forecasting: Weather forecasts are produced using numerical prediction models that solve physical equations describing atmospheric motion. This requires enormous computing power, which is why some of the world's most powerful supercomputers run around the clock.
• A shared naming system for clouds: Clouds in the sky are classified using a globally shared system of ten basic cloud types. The Latin names proposed by Britain's Luke Howard in the 19th century are still the international standard today.
• Different "weather days": Japan has its own "Meteorological Day" on June 1st, marking the start of weather observations by the Tokyo Meteorological Observatory in 1875, while March 23rd is the international day for thinking about weather worldwide.

Tips for Spending World Meteorological Day

• Open the latest version of your national weather service's website or app, and check the warning criteria for your area and the evacuation sites on your local hazard map to boost your disaster preparedness
• Look up at the sky and observe the shapes of clouds and the direction of the wind, sensing with your own senses the dynamism of Earth's constantly circulating atmosphere
• Read up on the latest international news about climate change, and deepen your understanding—from an objective viewpoint—of how global warming affects your life and the world's food production
• Listen carefully to weather presenters and consider the "observation data" and "forecast confidence" behind their reports, building your media literacy around weather information

An Intelligent Eye on the Sky Gently Protects Your Safety and the Future of Our Planet

March 23rd is a day to look at the sky above us through the eyes of science, and to feel gratitude for the workings of this great life-support system we call Earth. Weather can sometimes bare its teeth, but with accurate knowledge, observation technology, and cooperation among people around the world, we can predict its threats and overcome them together. Being sensitive to changes in the sky is also a reflection of a heart that loves and wants to protect nature. That curiosity—reading the wind, knowing the clouds—becomes a force that protects both your precious daily life and the beautiful climate we pass on to the next generation.