Climate of the Northeast Kingdom - Vermont

Long cold winters and short cool summers with adequate precipitation in all seasons best describes the climate of the Northeast Kingdom, Vermont. Summers are generally free of severe weather and extreme heat and humidity, but winters can have spells of severe cold. In addition, this area experiences a large winter to summer temperature range and very changeable daily weather.

The location of Northeast Kingdom (on the eastern side of a mid-latitude continent, in the hills between the Green and White Mountains, in northern New England, and about 100 miles west of the Atlantic Ocean) has a great influence on its climate. This location makes the region very susceptible to the frequent storm systems that march across the United States, but not as susceptible to severe summer weather or to coastal winter storms. Tornadoes are extremely rare in the area and only occasionally do the remnants of hurricanes or an "nor'easter" reach far enough inland to affect the weather of Northeast Kingdom.

The summers are short, but quite pleasant. The nights are cool and the afternoon highs are relatively free to extreme heat and humidity. The July average temperature is a cool 65F with afternoon high temperatures averaging 79F and morning low temperatures averaging 52F. We average only four days per summer of afternoon high temperatures above 90F and the upper 90's are very rare. In fact the hottest Northeast Kingdom has ever reached was 98F (in July of 1953).

Winters are long and cold. January temperatures average 12F with morning lows averaging 1F and afternoon highs averaging 23F. Almost every winter the temperature drops down to the -30F mark, with -41F in February of 1962 being the all-time coldest. The average date for the first 0F temperature reading of winter is December 4 and the average date of the last 0F temperature reading of the winter is March 18. Thus the heart of winter is usually 104 days long. We average 46 days per winter of morning low temperatures below 0F.

Precipitation throughout the year is quite uniform with few prolonged dry spells. This is due to frequent passage of mid-latitude migratory low pressure systems (with their associated fronts) in all seasons and occasional thunderstorms in the summer. There is dependable and adequate precipitation for most agricultural purposes. An average year has 180 days with measurable precipitation for a total of 41.25 inches. This great precipitation dependability is indicated by the fact that the probability of precipitation is near 50 percent for each day of the year and yearly totals show little variation from year to year. Unfortunately this also means a high probability of cloudiness. In fact, we have some of the lowest sunshine totals in the U.S. November and mid-March to mid-April are especially notable for their prolonged periods of cloudiness.

On the other hand, seasonal snowfall varies widely. It averages 94 inches, but in 1979-1980 there were only 55 inches (61% of normal) and in 1970-1971 there were 145.5 inches (162% of normal). The annual total accumulates as the result of many small snowfall events and only occasional major snowstorms. The snow season is long. Snow flurries have been observed during 10 months of the year and significant snowfalls (i.e., one inch or more) have occurred as early as October 10 in the fall and as late as May 11 in the spring. Continuous snow cover (i.e., one inch depth on the ground) lasts on the average for 134 days (November 25 through April 9). The maximum depth of snow on the ground usually occurs in the spring after the snow has been accumulating all winter. This maximum usually occurs in early March and averages 31 inches (it has been as great as 49 inches and as little as 17 inches). Although some new snow will continue to fall, with the increased sunshine after mid-April, the snow on ground diminishes very quickly, occasionally leading to spring flooding in the river valleys.

The transition seasons are times of long, slow change. Spring has a muddy beginning in mid-March and lingers into late May under the influence of cool air flow from eastern Canada. It is characterized by cool, damp, and cloudy days, the excitement of sugaring, and the threat of flooding from snow melt. Autumn extends from early September through mid-November. It commences with many warm pleasant days set against a backdrop of spectacular fall foliage and ends with another string of cool, damp, and cloudy days whose dreariness is broken by the excitement of the first significant snow flurries.

Since the Northeast Kingdoms climate is cool, the growing season (days between the last 32F reading in the spring and the first 32F reading in the fall) is short. The average last frost in the spring occurs on June 6 and the average first frost in the fall occurs on September 10 for an average growing season of only 96 days (the shortest was 55 days in 1965). The total heating degree day units which accumulate each year (a measure of fuel usage) are 9071, near maximum for the continental United States. On the other hand, the total cooling degree day units that accumulate each year (a measure of air conditioning usage) are minimal (138).

The Northeast Kingdom of Vermont is a good place for large woodpiles, warm clothes, thick walls and tight windows, and a hearty, self-reliant Yankee spirit!

This summary of the climate of the northeastern section of Vermont (The Northeast Kingdom) was written by Dr. Bruce Berryman of the LSC Meteorology Department