Whoever guessed closest to Monday, May 4th at 6:41 pm was right.

That's when the ice on the Yukon River at Dawson City started to move this year, as temperatures reached 12 degrees on Monday.

The annual breakup is a sure sign of spring.

Every year in Dawson City the breakup is marked by a clock which stops at the pull of a cable. The cable is attached to a tripod placed on the river's frozen surface.

The clock this year was again checked by a member of IODE, a group once called the Imperial Order of Daughters of the Empire. The charitable order of Yukon women dates back more than a century and has been running the ice-guessing contest since the 1940s.

The official website which tracks the Yukon River breaking says: "As the focus of a vigorous betting tradition, the exact time and date of breakup has been recorded annually since 1896."

The ice breakup this year is not unusual. Records show that most years it happens in early May.

The breakup is good news for local residents as it reduces the risk of flooding and means a local ferry will soon begin carrying people across the river.