Reports of rain round off Yellowknife’s warmest-ever year

Residents reported rain falling on New Year’s Eve in Yellowknife, a bizarre event that wrapped up the city’s warmest year on record.

Yellowknife’s hourly mean temperature in 2023 will be -0.5C, the warmest in a record stretching back to the 1950s.

The hourly mean involves taking all of 2023’s hourly temperature measurements from Yellowknife Airport and averaging the result.

This year’s hourly mean is the first in Yellowknife’s history to be warmer than -1C.

In 2022, the hourly mean was -4C. The average since records began in 1954 is -4.4C. Getting from -4C to -0.5C over the space of a year requires sustained periods of much warmer weather than usual.

Take December as an example.

In December this year, the hourly mean temperature in Yellowknife was -13.3C up to and including December 30.

That is far warmer than most Yellowknife Decembers. In 2022, the hourly mean was -25.1C.

Only one December on record was warmer than this – December 2005, where the hourly mean was -13.2C. But the summer of 2005 was nothing like as warm as 2023.

This year also becomes only the seventh on record in which Yellowknife did not experience a temperature of -40C without wind chill. Four of those years have come since 2010.

On New Year’s Eve, residents woke to the sound of light rain falling. By late Sunday morning, that appeared to have become freezing rain, though Yellowknife Airport’s weather station recorded the precipitation as light snow.

The weather record for Yellowknife contains no mention of rain on New Year’s Eve in the city’s history, though it’s possible that insignificant quantities of rain fell in the past but were not formally recorded.