International Amateur Radio Day

It all began in Paris on April 18, 1925, when amateur radio pioneers from 23 countries across Europe, the Americas, and Asia gathered for an International Amateur Congress with a bold idea: to give their scattered hobby a united voice. A constitution was adopted on April 17, and the formation of the International Amateur Radio Union was ratified on April 18, 1925. The protocol of the congress was written in English, French, and Esperanto, a fitting start for a hobby devoted to talking across borders. From those founding countries, a worldwide community was born, and April 18 has belonged to amateur radio ever since. Picture the scene: delegates in 1920s Paris, some of whom had built their own transmitters by hand, agreeing that their hobby deserved a united voice. Esperanto on the protocol was a lovely touch: a universal language for a universal hobby. They could not have imagined the wonders to come, but they built the foundation for all of it. It is humbling to think that every modern contact, from a kitchen-table chat to a contest heard around the world, traces back to that Paris meeting room.

The founders had something urgent to protect. Amateur experimenters had been the first to discover that the shortwave spectrum, dismissed by many as a wasteland, could carry signals around the entire world, a discovery that changed communications forever. But in the rush to use those shorter wavelengths, amateur radio was in grave danger of being pushed aside by bigger commercial and government interests hungry for spectrum. The pioneers met in Paris to create an organization that would defend and support amateur radio worldwide, and just two years later, at the 1927 International Radiotelegraph Conference, amateur radio won frequency allocations still recognized today: the 160, 80, 40, 20, and 10 meter bands. That victory secured the hobby’s home on the dial for a century to come. It was a landmark victory for the little station against the big interests, and it proved what organized amateurs could achieve. Those bands, 160, 80, 40, 20, and 10 meters, remain the backbone of the hobby, carrying voices, Morse code, and digital signals around the clock.

A century later, the IARU has grown from those founding countries to more than 160 member societies across three regions: Region 1 covering Europe, Africa, the Middle East, and Northern Asia; Region 2 covering the Americas; and Region 3 covering Australia, New Zealand, the Pacific island nations, and most of Asia. The International Telecommunication Union recognizes the IARU as the voice of amateur radio on the world stage. More than 3,000,000 licensed operators are on the air today, experimenting with new digital modes, competing in contests, building their own antennas and rigs, and making friends across oceans with a microphone or a Morse key. In 2025 the IARU marked its centenary with the theme “A Century of Connections,” celebrating 100 years of innovation, community, and advocacy, and each April 18 brings a new theme to carry that spirit forward. The centenary theme said it best: a century of connections. From spark-gap pioneers to software-defined radio, the tools have changed beyond recognition, but the thrill of hearing a distant voice answer your call has not changed at all. The equipment evolves, the wonder stays exactly the same, and that is why the hobby keeps winning new hearts a century later.

Amateur radio is also serious business when it counts. When storms knock out phones and the internet, trained volunteer operators step in with emergency communications that keep rescue teams and shelters connected, a role they have played in disaster after disaster. It is a gateway to science and engineering too, and many leaders in global communications trace the start of their careers to a humble ham shack and a first crackling contact that sparked a lifelong fascination. So on April 18, member societies take to the airwaves to show the public what they can do and to enjoy a little global friendship, one contact at a time. All it takes to join the party is curiosity, a listening ear, and a willingness to say hello to a stranger across the static. Many operators describe their first contact the way others describe a first love: the crackle, the call sign coming back, the sudden realization that someone on the other side of the planet is listening. April 18 is the day the whole world celebrates that feeling together.

THE STORY BEHIND INTERNATIONAL AMATEUR RADIO DAY

📡 Paris, 1925: A Union Is Born
Delegates from 23 countries met at the International Amateur Congress in Paris. The constitution was adopted on April 17 and the International Amateur Radio Union was ratified on April 18, 1925, in a protocol written in English, French, and Esperanto, a fitting start for a border-crossing hobby that now spans the globe. Three languages, one protocol, and a shared dream of the airwaves.

⚡ The Shortwave Gamble
Amateur experimenters were the first to prove that shortwave signals could circle the globe, turning a dismissed slice of spectrum into a worldwide highway. With commercial interests crowding the airwaves and the hobby in grave danger of being pushed aside, the pioneers created the IARU to defend the airwaves they loved. David versus Goliath, with antennas.

📻 Bands Won for a Century
At the 1927 International Radiotelegraph Conference, amateur radio secured the 160, 80, 40, 20, and 10 meter bands. Those allocations, won nearly a century ago through the IARU’s advocacy, are still recognized today, a lasting monument to what organized amateurs can achieve. Won in 1927, still on the air today.

🛳 Three Million Strong
The IARU now represents more than 160 member societies in three regions, recognized by the International Telecommunication Union as the voice of amateur radio. Over 3,000,000 licensed operators keep the airwaves lively, from weekend contests to emergency nets that spring into action when disaster strikes and other communications fail. When all else fails, amateur radio gets through.

WAYS TO CELEBRATE

📻 Listen to the Airwaves
Tune a shortwave receiver or an online WebSDR and listen for amateur conversations drifting in from other countries. You are eavesdropping on a century-old global party line, and it costs nothing to listen in on the friendship flowing through the static. Try the 20 meter band in the daytime; it is often alive with distant voices.

📡 Visit a Club Station
Find a local amateur radio club and ask about an open house or field day on April 18. Operators love showing off their rigs, explaining the dials and antennas, and answering every question, and you might even get to say hello on the air yourself. Bring your curiosity; operators bring the rest.

🌐 Learn the Lingo
Learn what “CQ” means, a general call inviting anyone listening to answer, and that “73” is ham shorthand for best regards. Drop a friendly 73 to a radio amateur and you will make their day, because every operator remembers the thrill of being answered. Two letters, CQ, open a conversation with the world.

Celebrate International Amateur Radio Day

So on April 18, look up at the invisible waves carrying voices around the planet and give a little wave back. CQ, CQ, this is Celebration Nation calling: 73 and happy Amateur Radio Day to every operator, experimenter, and midnight listener out there. Turn on a receiver, send out a call, and join a century of connections.