If you've been wondering what's going on with the iconic lights on top of the historic Canada Life building in Toronto's downtown core right now, you're not alone.

The famed topper of the landmark edifice at 330 University Avenue is being upgraded with LED lights, partly in the name of energy efficiency.

The illuminated tower, which was added to the 1930s Beaux Arts building in 1951, hasn't seen any considerable revamps in 66 years.

Are they upgrading the lights to LED’s on the Canada Life building? pic.twitter.com/nkmjdntOsK

— Mikey Riot (@mikeyriotphoto) November 27, 2019

Some may not be familiar with the fact that the 12.5 m tall structure of lights perched high above the city's streets actually serves as a weather beacon — the oldest of its kind in the country — relaying Environment Canada forecasts to residents across Toronto.

The coloured top box indicates if it's due to be clear (green), cloudy (red), rainy (flashing red) or snowy (flashing white).

The lights below the box broadcast whether the temperature is rising (lights running up), cooling down (lights running down) or remaining steady (no movement).

In total, there are 1,500 bulbs and nearly 3,000 m of wiring that comprise the building's glowing, characteristic crown.

You know that thing at the top the Canada Life building at Queen and University? That thing with lights that go up and down. Well, it’s a weather beacon that in 1951, long preceded the smartphone to help Torontonians know the forecast. Here’s the code to understand it: pic.twitter.com/WNjTaJkiiM

— Josh Matlow (@JoshMatlow) March 4, 2019

The current work will be completed by the end of next week, and will not alter how the beacon appears or operates — but will ensure it can continue to do so for many more years to come.