On August 18, 1926, a modest sheet of pale blue-green lines made history. It wasn’t flashy. It wasn’t even meant for the public. But it marked the first time a weather map was broadcast by radio from Arlington, Virginia, to the U.S. Weather Bureau in Washington, D.C..

A Technological Leap

The mastermind was C. Francis Jenkins, a pioneer of early television. Jenkins had already experimented with transmitting pictures via radio. The Weather Bureau asked: If you could send photographs, could you also send weather maps? The answer became an experiment that would change forecasting.

The process was ingenious for its time:

• The day’s weather map was drawn in black ink on thin white paper.
• A photographic negative was made, showing the map’s lines as transparent.
• This negative was wrapped around a rotating glass cylinder at the Navy’s Arlington radio station (Station NAA).
• As the cylinder spun, a pinpoint light shone through each transparent line, triggering a photoelectric cell that converted the light into electrical pulses.
• These pulses traveled by radio waves to a receiving station, where they controlled a pen on another spinning cylinder, recreating the map line by line.

Transmission took about fifty minutes. The result was crude but legible, a usable weather map, delivered without couriers or cables.

The Role of the U.S. Navy

The Navy didn’t just lend the transmitter; it tested the system’s reach. Ships like the U.S.S. Kittery and U.S.S. Trenton received the maps as far away as Guantanamo Bay, Cuba, sometimes even through thunderstorms. The trials proved that weather information could travel vast distances quickly, a potential boon for shipping and aviation.

Although we might call it “televised” in the sense that images were transmitted, there was no camera, no presenter, and no home audience. The recipient was strictly the Weather Bureau. It would take decades before weather broadcasts reached the public’s living rooms.

In Britain, for example, the Met Office had issued forecasts since 1861, but TV weather with an on-screen forecaster didn’t arrive until 1954. In the U.S., NBC’s Today show gave its first televised weather forecast on January 14, 1952, complete with a presenter.

Why It Mattered

This 1926 broadcast was about more than convenience. Before it, weather maps had to be mailed or telegraphed, often too slowly to be fully useful. By cutting delivery time to under an hour, the Jenkins method opened the door to near-real-time forecasting. For ships at sea and remote stations, that speed could mean the difference between safety and peril.

Jenkins’s radio weather map was a quiet revolution, a proof of concept for sharing visual data over the airwaves. Although eventually replaced by faster and clearer systems, the idea it embodied — that weather information should move as quickly as weather itself — still drives forecasting technology today.

From that flickering light in a glass cylinder to today’s animated radar on your phone, the line runs straight back to a summer morning in 1926, when the sky’s secrets began to travel at the speed of radio.