A blast of Arctic air over B.C. has sent temperatures plunging along the West Coast, triggering an outflow warning from Prince Rupert to Whistler, which could be extended as far south as Victoria later this week.

According to Environment Canada, the Arctic ridge in place over the Interior is pushing out to the coast along inlets and valleys.

Strong winds on B.C.'s north and central coasts and in the Whistler area could lead to wind chill values approaching –25 C overnight Tuesday and Wednesday.

The Arctic ridge has also pushed cold air further down into the South Coast, which may be subject to additional wind chill warnings beginning Wednesday, Environment Canada said.

Temperatures are expected to dip below –8 C in Metro Vancouver Tuesday overnight, and to plummet to –15 C with the added wind chill Wednesday overnight.

Forecast of temperature lows

Tuesday overnight

  • Metro Vancouver: –8 C
  • Greater Victoria: –7 C
  • Fraser Valley - west: –6 C
  • Fraser Valley - east: –16 C*
  • Howe Sound: –18 C*
  • Whistler: –24 C*
  • Sunshine Coast: –19 C*
  • Southern Gulf Islands: –7 C
  • East Vancouver Island: –8 C
  • West Vancouver Island:–6 C
  • Inland Vancouver Island: –8 C

Wednesday overnight

  • Metro Vancouver: –15 C*
  • Greater Victoria: –18 C*
  • Fraser Valley - west: –7 C
  • Fraser Valley - east: –18 C*
  • Howe Sound: –17 C*
  • Whistler: –25 C*
  • Sunshine Coast: –19 C*
  • Southern Gulf Islands: –6 C
  • East Vancouver Island: –7 C
  • West Vancouver Island:–16 C*
  • Inland Vancouver Island: –9 C

*Temperature lows calculated with wind chill predictions

Source: Environment Canada public text bulletins, 4pm Tuesday

Emergency shelters opened

With overnight temperatures in many parts of the South Coast set to plunge below –10 C Tuesday night, emergency shelters across the region are gearing up.

James Pratt, the extreme weather response coordinator for Metro Vancouver, says 384 additional spaces will be available this week at 17 different shelters.

Homeless in Vancouver

A homeless person covers up for the night in downtown Vancouver during a cold snap in December. (CBC)

"It's not a solution to homelessness of course, but it is a way to keep people safe and out of the cold on these kinds of extreme nights, because nobody should be out there when it's this cold," said Pratt.

Pratt says people can find the nearest shelter by dialing 211.

"These spaces are low barrier, which means there is not a lot of paperwork. There is just set up to get people in out of the cold for the night, get them some food, make sure they are dry and safe, and then hopefully they can find some other community resources through that as well," says Pratt.

Arctic ridge - cold air across B.C. West Coast

The Arctic ridge has also pushed cold air further down into the South Coast, which may be subject to additional wind chill warnings beginning Wednesday, Environment Canada said.