Wednesday, December 12, 2018

Victoria's Fall of 2018: slightly warmer and drier than nomal

November 30 marked the end of meteorological fall (September, October, and November), so it's time to take a look back at the fall of 2018 in Victoria.  Overall, the summer was slightly drier and warmer than normal.  This was due to warmer and drier than normal conditions in October and November, since September was actually slightly cooler and wetter than normal.

Victoria received 186 mm of rain during the September to November period at Victoria Gonzales.  That's about 18% less than the 30-year average fall rainfall of 226 mm.  Rainfall was actually a bit above normal in September (28 mm in 2018 vs. the average 24 mm).  However, this was followed by a drier than average October (50 mm vs. 72 mm) and November (108 mm vs. 130 mm).  

There were 39 days with measurable precipitation this fall, with 11 days in September, 13 days in October, and 15 days in November.  That's actually slightly above the 37 days with measurable rainfall that Victoria typically receives during the fall (7 days in September, 12 days in October, and 19 days in November).  

The chart below shows daily rainfall during fall 2018, and compares the cumulative rainfall with the 30-year average.  September and early October were slightly wetter than normal.  This was followed by a two-week dry spell during the middle of October.  The end of October and beginning of November was the wettest period of the fall, with  nearly half of Victoria's fall rainfall this year being recorded over a 9-day stretch from October 27 to November 4.  This period included the wettest single day of the fall: 19.6 mm on November 1.  The remainder of November was a little drier than normal.


Daily & Cumulative Rainfall in Victoria, Fall 2018
The chart below compares the rainfall amounts in Victoria this fall with other locations in the regions.  As is typically the case, Victoria Gonzales had the lowest amount, with a total of 186 mm.  Victoria Airport had 280 mm mm of rain throughout the fall, about 50% more than Victoria Gonzales.  It was wetter still in Vancouver, with 425 mm at the Vancouver Airport and 552 mm at Vancouver Harbour - nearly 3 times what Victoria received.  By comparison, it was relatively dry in Seattle, with 260 mm.  That's less than Victoria Airport received, but still about 40% more rainfall than Victoria Gonzales.  

Fall 2018 Rainfall


The mean temperature this fall at Victoria Gonzales was 11.4 degrees, warmer than the 30-year average of 11.0.  Fall 2018 was tied for the 21st warmest in 105 years of record-keeping at Gonzales, so only about 1 in 5 falls have been warmer.  (Fall 1987 was the warmest on record, at 12.3 degrees.)  September 2018 was actually a bit cooler than average (14.3 degrees vs. the average 14.6).  However, both October and November were warmer than average.  In October it was 11.2 degrees vs. the average 10.9, while in November it was 8.7 vs. the average 7.5 degrees.  November was the 14th warmest on record at Victoria Gonzales (going back 105 years).  

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales during fall 2018, compared with the 30-year averages.  You can see that September was generally a bit cooler than average, while October and November were both a bit warmer than average.  The warmest day of the fall was 23.3 degrees on September 5, although it also reached 23.1 degrees on September 28, which was a greater anomaly from the average (which is 17.5 degrees for that date).  The coolest temperature was 2.7 degrees on November 19.


Daily Max & Min Temperatures in Victoria, Fall 2018

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