A cold and dry January in Victoria

January was another cold month in Victoria, following a cold December, with continued “Arctic outbreaks” of cold dry air from the B.C. Interior, interspersed with periods of milder Pacific air.  The mean monthly temperature of 3.9 degrees was nearly a full two degrees below the 30-year average of 5.8 degrees.  In fact, January 2017 was the coldest January since 1993 - nearly 25 years ago.  The average daily max and min temperature in January was 6.2/1.5, compared with the normal of 7.7/3.8.  The warmest temperature during the month was 12.2 degrees on the 17^th, while the coldest temperature was -3.2 degrees, recorded on both the 3^rd and the 12^th.  The daily maximum exceeded the monthly average of 7.6 degrees on only 10 days this January.  On the other hand, the overnight minimum was lower than the monthly average of 3.8 degrees on 25 days this January.  There were 9 days when overnight lows dropped below freezing, compared with the long term average of 2.9 days.

The chart below shows the daily maximum and minimum temperatures in Victoria this past month, compared with the average temperatures.  You can see that temperatures were below average during the first half of the month (with an average daily max/min of 3.6/-0.9).  The second half of January saw slightly above average temperatures ( average max/min of 8.5/3.9), except for a dip during the last few days of the month.

Daily Maximum and Minimum Temperatures, January 2017

While January 2017 was cold, the frequent Arctic outbreaks meant it was also dry.  There was only 24.7 mm of precipitation recorded at Victoria Gonzales in January.  This is about one quarter of the normal 104 mm, making this January the 5th driest in the past 100 years at Victoria Gonzales.  Victoria saw precipitation on just 8 days in January 2017, compared with the usual 17 days.  Two thirds of the month’s rainfall came in a short 3-day stretch from January 17 to 19.  Despite the cold, there wasn’t much snow in Victoria this January, just a 1 cm dusting on January 1^st that melted away by noon.

The chart below shows daily and cumulative precipitation in Victoria this January, compared with the long-term average cumulative precipitation.  You can see that the amount is well below normal.

Daily and Cumulative Precipitation, January 2017

As I’ve mentioned many times on this blog, Victoria tends to get significantly less rainfall than surrounding areas, and this past month that trend was even more evident.  The chart below compares the total precipitation for January 2017 at Victoria Gonzales and a number of nearby locations.  The Victoria Airport, 30 kms to the north, had  more than twice as much precipitation as Victoria Gonzales.  Nanaimo had 3 times as much precipitation as Victoria, Seattle had more than 4 times as much, and Vancouver had more than 5 times as much.  In the winter time, the differences usually aren’t this great.  The Arctic outbreaks we had this month tended to push the jet stream further south, with lots of precipitation going into California.  As a result, Los Angeles, received  over 200 mm of rain - more than 8 times as much as Victoria.