Wednesday, January 2, 2019

2018 Year in Review

2018 was warmer and slightly drier than average in Victoria.

The mean temperature at Victoria Gonzales for 2018 was 11.0 degrees C, almost half a degree above the 30-year average of 10.6 degrees.  2018 was the 18th warmest year on record at Victoria Gonzales, going back 105 years.  The warmest year on record was 11.7 degrees in 2015.  It was also warmer than average at the Victoria Airport (10.7 degrees versus the average 10.1 degrees).  On the other hand, the  mean temperature at the University of Victoria was 10.9 degrees, which is slightly below its long term average of 11.1 degrees.

Ten of the twelve months had above normal temperatures, with only February and September being cooler than average in 2018.  While February 2018 was 1.2 degrees cooler than normal, both May and December were 1.2 degrees warmer than normal - the largest positive monthly anomaly in 2018.  July was a close third, being 1.1 degrees warmer than normal.

While 2018 was warmer than average, there were few extremely warm days during the year.  The warmest temperature was 27.2 degrees on August 14.  The warmest annual temperature at Victoria Gonzales is above 30 degrees roughly 50% of years.  The coldest temperature in 2018 was -2.2 degrees on February 21.  There were 7 days in 2018 when the temperature went below 0, compared with the long-term average of 9.5 days.

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales in 2018, compared with the long-term normal temperatures.  You can see the cold snap in late February, the unseasonably warm weather in May, as well as the generally warmer than average temperatures throughout the year.

2018 Daily Max & Min Temperatures at Victoria Gonzales

2018 was slightly drier than average in Victoria.  There was 594 mm of precipitation, 91% of the normal 654 mm.  Seven months were drier than normal.  Victoria typically experiences its driest weather in the summer months, and this year it was even drier than normal, with only 29 mm of rain from May to August, well under half the  normal 80 mm of rain for the period.

Thanks to its location in the Olympic Mountain rain shadow, Victoria receives less precipitation than surrounding locations, and 2018 was no exception.   The chart below compares annual precipitation in 2018 in locations around Victoria, Vancouver, and Seattle.  The Victoria Airport recorded 863 mm, 45% more than than the 594 mm at Victoria Gonzales.  The Seattle Airport received 908 mm of precipitation in 2018.  The Vancouver Airport recorded 1343 mm of precipitation while Vancouver Harbour recorded 1731 mm.  Interestingly, while locations in Victoria and Seattle were a bit drier than normal in 2018, the Vancouver locations were wetter than normal.  While Vancouver Harbour, on average, gets just under two and half times as much precipitation as Victoria Gonzales, in 2018 Vancouver got nearly 3 times as much.

Annual Precipitation in 2018


The chart below shows daily and cumulative precipitation at Victoria Gonzales in 2018.  You can see that the cumulative precipitation in 2018 (red line) fairly closely followed the long-term average trend (blue line).  Early spring was a little wetter than normal, followed by the dry summer.  Cumulative rainfall almost caught up to normal in November, but then fell slightly behind again by the end of the year.

2018 Daily & Cumulative Precipitation at Victoria Gonzales

There were 126 days with measurable precipitation in 2018, a little under the normal of 131 days.  The wettest day in 2018 was January 11, with 27 mm.  That was, in fact, the only day in 2018 with more than 25 mm of rain.  The long term average for Victoria Gonzales is 3 days per year with 25 mm or more precipitation.  There were 14 days with at least 10 mm of rain, compared with the  normal of 16 days.

Victoria had less snow than average in 2018, with 6 cm of snow, all of it recorded on February 21.  The long term average for Victoria is 21 cm of snow and 3 days with snowfall.  There was snow on the ground for 2 days compared with the long term average of 4.8 days.