SW AP-060 CA-816037 Aurora Borealis - Canada

The Northern Lights (Aurora Borealis) can be seen on a clear winter night from many parts of northern Canada.

From an official site of the Canadian Tourism Commission (quite a sales pitch!):

Race to the window or run outside to see ribbons of green, red, blue and purple rippling across the sky, gathering momentum until the Northern Lights shimmer and loop over the entire horizon in surreal swathes of colour. Watch in silence in Nunavut and you’ll understand how many Inuit believe the lights become so intense they sing or crackle. The Aurora Borealis is Mother Nature’s light show so grab a front row seat in fall, winter and early spring when nights are long and dark. Try your luck at fly-fishing for Arctic Char by the lights of the Aurora in far Northern Quebec or pair light-peeping in the Northwest Territories with a locally sourced, gourmet meal of caribou, or pickerel plucked from an icy lake near your log lodge. The Aurora is so bright it can light the way for snowmobilers on Labrador's epic Cain's Quest or for dog mushers and cross-country skiers in the Yukon. But the breathtaking displays are just as enjoyable from within the cozy confines of a cabin, tent or glimpsed through the steam of an outdoor hot tub in the lap of luxury. Then slide under a duvet or into a sleeping bag and dream of Technicolor cosmic fairies.

This beautiful postcard was sent by Sarah K (blubutterfly) of Alberta, Canada (23 April 2014) Swap-bot.
.....
This second postcard is a Zazzle card from Meeghan (Postcrossing, July 2018) who said that they could see the Northern Lights from their home location.

and the stamp that she used also shows (I think) the Northern Lights over Canada.