Berkeley Weather Beacon in Boston, Massachusetts

The Berkeley Building, affectionately known as the “Old John Hancock Building,” is a 495-foot tall, 26-story office building located in the Back Bay neighborhood of Boston, Massachusetts. Completed in 1947, the building was the second tallest in the city until the completion of the Prudential Tower in 1964. However, it remains an iconic Boston landmark. A drawing of the building even appeared for many years as part of the John Hancock Insurance Company logo.

Bostonians may best know the Berkeley Building for its lighted weather beacon. In 1950, a 65-foot tall tower was installed on the building’s roof. First lit on March 15, 1950, the seven-story tall structure is illuminated by 288 red and blue neon lights.

The color and pattern of the lights indicate the Boston weather forecast. The weather beacon is run from an operations center in the building’s basement and controlled by a series of electrical switches. Building engineers regularly monitor the National Weather Service and modify the lighting based on weather projections. On clear days, the beacon can be seen from miles away and serves as a landmark for passengers flying into Boston’s Logan Airport.

A clever rhyme helps people interpret the lighting patterns: “Steady blue, clear view/Flashing blue, clouds due/Steady red, rain ahead/Flashing red, snow instead.”

The beacon faithfully forecasted the weather until 1973, when it was shut off to serve as an example of the power of conservation during an energy crisis. It was relit in 1983. The beacon temporarily stopped forecasting the weather again on March 9, 2020 due to the Covid-19 pandemic, as the steady blue lights were used to celebrate hospital workers. 

In addition to forecasting the weather, the beacon sometimes provides information about the Boston Red Sox baseball team. Flashing red lights indicate when a home game at Fenway Park is postponed. In 2004, the beacon flashed blue and red simultaneously for the very first time to celebrate the Red Sox World Series victory after a drought of 86 years. That event required adding a new line to the rhyme: “Flashing Blue and Red, when The Curse of the Bambino is dead.” The blue and red flashing was repeated in 2007 and 2013 when the World Series trophy returned to Boston.

Smartphones have now made the beacon somewhat obsolete. However, representatives of John Hancock Insurance promise that the weather beacon will continue to forecast Boston’s weather for many years to come.