Corley Sunday, 9, and her 6-year-old brother, Adin, play in the sprinkler at their home in Paris on June 23, 2020. Southern Maine’s warmest period last year was between June 1 and July 15, with July being the all-time hottest month on record. File photo by Daryn Slover/Sun Journal Buy this Photo

The year 2020 will be remembered for decades to come for so many reasons that aren’t related to the weather. All we can do is hope there won’t be another one like it. Once again here in Maine, we’ve shown how resilient we are and how, in spite of the fluctuation of our four seasons, we’ve put our ingenuity and coping skills to use and learned to adapt, whether facing heat, dryness or COVID-19.

With all the headline-making news we’ve had to deal with on a daily basis, some folks may not realize that 2020 was southern Maine’s (Portland) warmest year on record. The average temperature was 49.4 degrees; 2.9 degrees above normal. Portland also reported the all-time warmest summer ever recorded, and the warmest July on record. And that record was broken despite the city experiencing its coolest July 4 in 22 years, with the high temperature only reaching 70 degrees.

“Daily records for the year included many warmest high and low temperatures, but no coldest high or low temperatures. This is a trend we’re seeing, with more warmest records and fewer coldest records being broken, as a result of climate change,” said Jessica Spaccio, climatologist at the Department of Earth and Atmospheric Science, Northeast Regional Climate Center, at Cornell University in Ithaca, New York.

For comparison, previous records set for warmest years were in 2010 and 2012 with 49.2-degree averages. The coolest year was 1962, with an average 43.3 degrees.

This year’s findings should come as no surprise. Our planet’s global average surface temperature in 2020 tied with 2016 as the warmest year on record, according to an analysis by NASA.

“The last seven years have been the warmest seven years on record, typifying the ongoing and dramatic warming trend,” wrote Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, in the organization’s year-end report. “Whether one year is a record or not is not really that important – the important things are long-term trends. With these trends, and as the human impact on the climate increases, we have to expect that records will continue to be broken.”

Portland felt this trend as the city experienced a long summer simmer with warm temperatures and high humidity, including 13 total days of temperatures reaching 90 degrees or more. They included three straight days of 90+ temperatures, a heat wave the likes of which hasn’t happened in nine years. The humidity blocked the cooling relief that usually comes with lower evening temperatures in Maine. The result is that temperatures never went lower than the 70s for several days and featured a tropical-like atmosphere.

The low temperature on July 27 didn’t drop below 78 degrees, by far the warmest low temperature ever recorded in Portland.

2020’s growing season, as defined as the longest consecutive days above freezing, was 169 days, from April 23 (one of the earliest official spring freezes on record) through Oct. 9, 10 days longer than the norm of 159 days. (The longest growing season recorded to date is 197 days in 2014.)

This past year’s growing season was a conspicuously dry one, with total precipitation of only 41.48 for the year. That’s 5.77 inches below normal, giving the area the driest year since 2004 even though there were 14 days with at least 1 inch of rain, 2.5 days more than normal. (To compare, the wettest year was in 2005 with 66.45 inches of rain measured.)

The below-normal precipitation measurement, above-normal temperatures, low streamflow, and declining soil moisture led to the expansion of abnormal dryness and the introduction of moderate drought to all of New England during June. These conditions expanded in Maine with warnings of harmful algal blooms for lakes, reports of wells going dry, and farmers noting they were watering crops more frequently.

Perhaps not surprising, 2020 was the worst year for wildfires in the state in 20 years with over 1.000 reported.

To add to Maine’s drought conditions, snowfall statistics (normally listed by season rather than by calendar year), showed that 2020 had 53.3 inches of total snowfall, 8.6 inches below normal. This was the first calendar year with below normal snowfall since 2010. Within the calendar year, there were 11 days where a measurable depth of an inch or more of snowfall was recorded, including only two storms with more than 6 inches: On Jan. 16, 2020, 6 inches of snow fell, while the biggest snow of the year started falling on Dec. 17, 2020, and 17.6 inches were measured in a little more than 12 hours.

A SEASON-BY-SEASON GLANCE

WINTER

Winter 2020 wasn’t much to write home about. The first snowstorm of the year on Jan. 16 with its mere 6 inches of snow was hardly enough to cause excitement, even if it did turn out to be one of the biggest storms of the year. Jan. 21 gets the prize for the coldest day of the year with its temperature of minus 4, one of only three days when the temperature dipped below 0 degrees.

An inch of rain ushered in February — an indicator of the record-breaking warm year ahead? — but snow bunnies became hopeful when 5 inches of snow fell on Feb. 6 and the temperatures were cold enough to sustain the snow pack. Those conditions didn’t last long, however. Mild weather and heavy rain at the end of the month washed most of that snow away.

A 61-degree day on March 3 signaled an early spring, and to punctuate that, Portland experienced a record-breaking day on March 9 when the temperature climbed to 70 degrees, the earliest 70-degree day on record.

Another snowstorm dropped almost 6 inches of snow over March 25 and 26, but it melted so quickly it was not considered “measurable,” with returning mild weather and incoming rain finishing it off.

SPRING

The next few months were frequently cloudy and wet. In fact, from April into June, there were 47 days with measurable precipitation in Portland, the most since 1973. The heaviest rains fell on April 26 and 27, then again on May 28 and 29.

Days of special note include April 9 and 10 when Portland had 3 inches of heavy, wet snow and strong winds that downed trees and caused more than 266,000 households and businesses — about a third of the state — to lose power. Coastal flooding was also documented. The last freeze of the season was April 23.

On May 9, the temperature dropped enough to change this rainy day over to a snowy one. Although the surprise snow didn’t accumulate to measurable depth, it was definitely a rarity to have snow that late in the season and more than two weeks after the last official freeze was recorded. Soon after, conditions changed dramatically as hardly any precipitation fell over a 40-day period that began in mid-May.

As a matter of fact, between May 16 and June 27, Portland had only .38 inches of precipitation, the least amount in that same period since records started to be kept in 1871.

The most notable warm days were April 13, when temperatures reached 73 degrees, and May 26, when the temperature soared to 84 degrees. This dry spell continued to the end of June, when over the last three days of the month thunderstorms heralded in 3 inches of rain.

SUMMER

Portland’s warmest period occurred between June 1 and July 15, with July being the all-time hottest month on record. The hottest minimum temperature for any month since 1940 was a recorded low of 78 degrees on July 27. The average temperature for the month was 73.7 degrees, which was 4.6 degrees above normal and the warmest month on record at Portland, surpassing 2019’s record-setting July by .6 degrees.

Tropical Storm Isaias broke the heat wave and humidity in early August, bringing in cooler, drier weather. Even so, Portland recorded six days with a high of at least 90 degrees for that month, tying the existing record for August.

More than an inch of rain fell on Aug. 29, but this was the last significant rainfall for a while as drought conditions intensified in September.

FALL

Fall 2020 was the 8th driest on record with only 18 per cent of normal precipitation in Portland, even though on Sept. 29 and 30 a storm system brought rain with wind gusts up to 72 mph. More than 100,000 customers in the state lost power during that storm.

Maine’s drought conditions continued, but frequent storms with howling winds and heavy precipitation helped to ease those concerns a bit by mid-October.

The remainder of the fall had some ups and downs with colder than usual temperatures and even some snow the day before Halloween. Conversely, the temperature was over 60 degrees on seven days in November. Three of those days were over 70 degrees, with a high of 74 degrees on Nov. 7, tying with the warmest November temperature on record.

A stormy weather pattern cast away that warm spell with 52 mph winds and heavy rain on Nov. 30 into Dec. 1. A Nor’easter with rain, snow and gusty winds from 40 to 70 mph shook things up on Dec. 5 and 6. Heavy snow and strong winds brought down limbs and wires, resulting in power outages for approximately 230,000 households and businesses, more than a quarter of the state.

Colder temperatures prevailed, readying us for the biggest snowstorm of 2020, when 17.6 inches of snow fell within a bit over a 12-hour period in Portland beginning on Dec. 17. The storm helped to put us in the mood for the upcoming holidays, but our dreams of a white Christmas were dashed when high winds and heavy rain moved in on Dec. 25, washing away nearly every trace of snow, as we segued quietly and hopefully into 2021.

2020 ANNUAL STATISTICS
— Total precipitation: 41.48 inches; historical average: 47.25
— Total snowfall: 53.3 inches; historical average: 61.9
— Average temperature: 49.4 degrees; historical average: 46.5
— Average high temperature: 58.5; historical average: 55.8
— Average low temperature: 40.3; historical average: 37.2
— 13 days with temperature of 90 or hotter (ranks the 3rd most: 1955 was 16; 1988 was 15); historical average: 4.6 days
— 3 days with temperature below 0; historical average 7.7
— High temperature: 94 on July 20
— Low temperature: -4 on Jan. 21

RECORDS BROKEN IN PORTLAND IN 2020 FOR THE SPECIFIC DATE

Warmest maximum temperature
— Jan. 11: 63
— March 3: 61
— March 9: 70
— Nov. 6: 71
— Nov. 7: 74 (ties for record warmest November day)
— Nov. 11: 69

Warmest minimum temperature
— July 20: 73
— July 27: 78
— July 28: 73
— July 30: 69
— Aug. 12: 72
— Sept. 10: 66
— Sept. 28: 65
— Sept. 29: 63
— Nov. 11: 53
— Dec. 25: 47

Most precipitation
— April 9: 1.33 inches
— Oct. 13: 1.96 inches
— Nov. 23: 2.32 inches
— Dec. 5: 1.99 inches


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