The Coldest Day in British Columbia’s History

As a followup to British Columbia’s most extreme heatwave, this page looks at the province’s most extreme coldsnap. As with before, it’s not an examination of the coldest week, month, or season, and instead is a comparison of extreme cold days. The temperatures are mostly listed in Fahrenheit because that’s what they were recorded as back when the province used to actually get winters. Additionally, the Fahrenheit numbers sound more impressive than the Celsius ones.

The most extreme cold I have experienced in my lifetime happened in November of 1985 (and the same goes for you too if you were born after 1968), so that year will be our reference by which we judge all others. In line with the extreme heatwave format, Figure 1 compares November 1985 with the other 15 coldest days on record.

extremecoldBC

Figure 1: British Columbia’s 16 most extreme cold snaps.

The temptation is to look at the province’s all time extreme coldest temperature, set on January 31st, 1947 at Smith River, and declare that coldsnap the winner — but should an extreme event in the far north count if it didn’t spread to the south? Of course not. Therefore, all weather stations across the province are treated equally; 20 degrees below average in Kelowna is equivalent to 20 degrees below average in Fort Nelson.

14mostextreme

Figure 2: Timeline of BC’s most extreme coldsnaps.

Figure 2 displays the coldsnaps on a timeline. The 1985 coldsnap is the only one from November, and half the remaining dates occurred in January with the rest divided between December and February. Notice that such events stopped after the winter of 1968/69, which incidentally enough, was the coldest winter ever recorded in BC (in terms of the average winter temperature). It’s almost as if Mother Nature pushed out one last hurrah that year, and had nothing left to give.

ColdestDay

-80 at Mayo, Yukon

Severe cold spells used to hit every five years before around 1960. Mid-January of 1911 was the harshest to strike the northeast. The Peace area was especially hard hit, and down river from Fort St. John at Fort Vermilion, Alberta,  the temperature plunged to −60.6 °C (−77 °F). This is the coldest temperature ever record in Canada outside of the Yukon. In fact, there’s only ever been three other years where a temperature this cold was recorded in North America.

  1. February 1947: -81.4°F was recorded at Snag, Yukon;  -80°F was recorded at Mayo, Yukon
  2. January 1971: -80°F at Prospect Creek Camp, Alaska
  3. January 1997: -77°F at Manley Hot Springs, Alaska

The January/February coldsnap of 1947 spilled into BC, and on January 31st, Smith River, BC set the province’s all time record at -74 °F (-58.9°C). The extreme cold didn’t penetrate that far into the province, however, leaving it at only 14th spot all time province-wide.

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Okanagan Lake in 1936

There have been others as well, but two coldsnaps stand head and shoulders above the rest — December of 1968 and January of 1950.

The winter of 1968/69 was brutal from north to south, and even though the temperatures bottomed out in December, the deep freeze in January was almost as cold and much longer. On the south coast, the Lower Mainland managed an astounding 14 days in a row without the temperature rising above freezing. And in the north, Lower Post, near the Yukon border, averaged below -30°C (-22°F) that winter — a feat that has never been matched anywhere in the province before or since.

The winter was cold, but the extreme cold days occurred at the end of December of ’68. The Chilcotin weather station at Puntzi Mountain, situated in the lower third of the province, dropped down to a bone chilling -63°F (-52.8°C), marking the coldest temperature ever recorded in the province during the month of December. Northern cities like Whitehorse and Yellowknife don’t even get this cold. Even in the mild Okanagan valley the temperature was ridiculously cold. Kelowna set the city’s all time record at -33°F (-36.1°C) as did Vernon with a reading of -38°F (-38.9°C).  Victoria broke that city’s all time record cold with a reading of 4°F (-15.6°C).

The only other extreme cold snap that trumps the late December 1968 surge happened 19 years earlier in January of 1950. At that time, British Columbia went into a deep freeze for 6 solid weeks, and the cold was so intense that homes were left without water after city pipes froze solid. Okanagan lake froze 20 cm thick all the way across and Prince George averaged 20 degrees Celsius (36°F) below average for the month. In the middle of this coldsnap, the temperatures in the central interior were so cold that even the Inuit were impressed.

The official weather stations at Prince George and Kleena Kleene dropped to -58°F (-50°C), while anecdotal reports exist about unofficial readings of -60°F at Lone Butte, -72°F at Lac La Hache, and -74°F at Puntzi Mountain.

Elsewhere, official records show that Vavenby was -51°F, Westwold near Vernon was -50°F, and Joe Rich Creek near Kelowna was -45°F (Joe Rich Creek managed to exceed this mark in 1968 by two degrees). The Okanagan valley bottom itself remained above -40 in 1950, but the extreme and prolonged cold had a devastating impact on the fruit industry. If such an event were to strike again, the impact would be worse because orchardists have become complacent with their choice of frost-hardy fruit after four decades of mild winters.

1950 on the BC coast also experienced new records. The Vancouver airport, situated by the water, set the all time record of 0°F (-17.8°C). This temperature was matched almost 20 years later in December of 1968. While some places managed to match or even beat their all time records in 1968, most of the province was colder in 1950.

On a final note, measureable changes in extreme cold even over the years might leave you tempted to concluded that extremes are becoming less frequent as we warm, and you would be right if we stick to extreme cold, but extreme heat is largely replacing the lack of extreme cold. Figure 3 below highlights this trend.

extrmeheatandcold

Figure 3: Graphical representation of British Columbia’s most extreme temperature events.

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3 Responses to The Coldest Day in British Columbia’s History

  1. Pingback: British Columbia’s Most Extreme Heatwave | Questioning The Data

  2. M. Watts says:

    In the third paragraph you mention Ft. smith as the coldest place in BC at 74 deg F. I believe you mean Smith River. Ft. Smith is in the NWT. A not uncommon mistake.

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