October was Nunavut’s warmest on record, and climate change is to blame: meteorologist
Most of territory hovered 5 C above normal on average last month
With less ice and snow, the weather has felt unusually mild in Nunavut this autumn, and now there are numbers to back it up. Environment and Climate Change Canada says this October was the territory’s warmest on record.
The warming trend was seen across Nunavut, all the way up to its northernmost communities. In fact, Resolute saw six days stay above freezing in October this year alone. The total number of times the community has ever seen the mercury stay above zero for that month since weather data for the area has been recorded? Eight.
“Resolute is indicative of what we are seeing,” Castellan said.
Most of Nunavut was around 5 C warmer than usual last month, while the north Baffin area was 8 C warmer than usual.
Hundreds of individual daily temperature records were broken across the territory, too. The department records daily highs and daily low temperatures for every Nunavut community. The department measured record-breaking high temperatures 135 times throughout the month, and daily lows stayed warmer than ever 184 times.
Nunavik had higher temperatures last month as well, he said. For example, Puvirnituq was 5 C warmer on average than usual for the month of October.
There are multiple reasons for the record-breaking temperatures, Castellan said.
Wind patterns throughout Canada interacted in a way that brought warmer winds up from the south, he said.
But what exacerbated the warm winds was a lack of sea ice for this time of year, Castellan said. Sea-ice coverage has been below average in the Canadian Arctic for the entire year.
Usually, sea ice cools warm southerly winds, preventing warmer temperatures in the North. Without the usual amount of sea ice for October, those warm southerly winds stayed warm.
The thinning and disappearance of sea ice is a long-term consequence of climate change, Castellan said, and its effect on thermometers makes that effect measurable.
For example, temperatures in the Arctic are around three times warmer than pre-industrial times, while parts of the globe near the equator are now 1.5 degrees warmer than pre-industrial times.
“It’s virtually impossible to have this type of climate without [a changed environment],” he said.
Castellan said the unusual temperatures aren’t going away soon — people across the North can expect a warmer than usual start to winter too.