As January draws to a close, I want to reflect upon the past year’s weather before 2018 gets any farther away in the rearview mirror.
Temperatures holding steady
Month to month, average temperatures were up and down throughout the year. Some months were cooler than normal and some warmer.
January and February were both warmer than average, followed by much-cooler-than-average temperatures in March and April. Then we had a fairly normal May, June and July, followed by below-normal temperatures each month from August through December.
When you boil the temperatures down to annual averages, here is how they came out for the entire year:
• The average high temperature was 52 degrees. That is 2 degrees cooler than the historical average of 54 degrees.
• The average low temperature was 25 degrees. That is 2 degrees warmer than the historical average of 23 degrees.
• Averaging the annual high and low temperatures for the year provides an annual mean temperature, which was 38.5 degrees for 2018. Remarkably, that is exactly Jackson’s average annual mean temperature. This year we nailed it.
Temperatures in 2018 mimicked the two previous years. Both 2016 and 2017 had high temperatures that were cooler than the long-term average, along with low temperatures that were warmer than the long-term average.
The good explanation of that trend has to do with annual precipitation.
Considerably wetter in Jackson
For the last three years running, the town of Jackson has been wetter than normal.
Total precipitation in town for 2018 was 19.1 inches. Jackson’s long-term average annual precipitation is 15.84 inches. That extra 3.26 inches puts 2018’s precipitation at 21 percent above the average.
In 2017 total precipitation in town was 23.27 inches, 47 percent above average.
Annual precipitation in 2016 was between 2017 and 2018’s totals.
Wetter-than-normal years usually translate to a greater number of cloudy days, resulting in cooler daytime high temperatures. A greater number of cloudy nights usually results in warmer overnight temperatures.
Let it snow
Total snowfall from January through December was 84 inches, 7 inches more than the long-term average annual snowfall in town of 77 inches.
That makes three calendar years in a row with above-normal annual snowfall in the town of Jackson.
The annual snowfall number is a bit misleading, since it spans parts of two winters. While the winter of 2017-18 was below normal for snowfall, 2018’s total received a boost from the nearly 2 feet of snow that fell during November.
Highest highs, lowest lows
The hottest day of 2018 was Aug. 11 at 90 degrees. It’s the first time the Jackson Climate Station has recorded a high temperature of 90 degrees since Aug. 1, 2008.
But despite that high of 90 degrees August ended a full 3 degrees cooler than normal.
The coldest day of 2018 was Dec. 5, when the thermometer hit minus 16. As a side note, on Jan. 1 the low temperature hit minus 25 degrees.
May was the wettest month of 2018, with a total of 3.44 inches of precipitation, nearly double the May average of 1.80 inches.
As mentioned, November was the snowiest month, with 23.5 inches in town. That is well above the average November snowfall of 9 inches, but well short of the record November snowfall of 40 inches set back in 1985.