Quarterly climate impacts and outlook for the Gulf of Maine region: December 2020

Gulf of Maine region significant events – September to November 2020

Long description 

The image shows text highlighting significant weather and climate events that occurred in the Gulf of Maine region in the months of September to November 2020:

The region experienced record-setting warmth in early November.
Drought conditions persisted through autumn in parts of the region.

The text overlays a background map of the Gulf of Maine region, which includes: New Brunswick, Nova Scotia, and Prince Edward Island, Maine, New Hampshire, and the eastern half of Massachusetts.


Several frosts in mid-September cut short an already difficult growing season. Caribou and Bangor, ME, had one of their 10 shortest growing seasons.

From September 26 to 30, high temperatures of up to 30°C (86°F) and low temperatures above 16°C (60°F) set dozens of temperature records in the region. Caribou, ME, had its second-latest day in the year with a high of at least 27°C (80°F).

A storm system from September 29 and 30 ended the warm spell and brought up to 76 mm (3 in.) of rain. Wind gusts of up to 116 km/h (72 mph), highest in Massachusetts, caused over 165,000 New England customers and around 49,000 Maritimes customers to lose power. Downed trees and wires led to road and school closures in New England.

Bangor, ME, had its driest September on record, while Caribou, ME, had its second driest, and Woodstock, N.B., had its third driest. Caribou had its second-fewest number of days with measurable precipitation for September.


October featured frequent storms.

On October 7, a derecho with wind gusts of up to 132 km/h (82 mph) produced widespread damage in Massachusetts and southern New Hampshire. Numerous trees were downed due to strong winds, drought stress, and being fully leafed. In Massachusetts, nearly 240,000 customers lost power and there was an EF-0 tornado. The system produced wind gusts  of up to 102 km/h (63 mph) in the Maritimes.

The first measurable snow of the season fell in northern Maine and the Maritimes from October 26 to 27, with the greatest total of 10 cm (4 in.) in Doyleville, N.B.

Caribou, ME, had its third-wettest October on record.


The region experienced unusual warmth from November 6 to 12, with high temperatures up to 25°C (77°F). More than 30 Maritimes sites and Portland and Caribou, ME, recorded their all-time hottest November day on record. In fact, multiple days during the period ranked among the 10 warmest for November. For instance, Caribou had its hottest November day as well as its second, fifth, and eighth hottest November days. Low temperatures around 10°C (50°F) ranked among the 10 warmest for November at a few sites.

November featured frequent storms.

For instance, a storm from November 1 to 2 brought up to 70 mm (3 in.) of rain, light snow, and wind gusts of up to 100 km/h (62 mph) to the Maritimes, cancelling ferry crossings.

A storm from November 30 to December 2 dropped up to 208 mm (8 in.) of rain. The greatest totals were in southern New Brunswick where some homes flooded and a family was trapped. Wind gusts of up to 113 km/h (70 mph) downed trees and wires, leaving more than 100,000 customers in Maine without power.

Regional climate overview – September to November 2020

Temperature: autumn departure from normal

Map of temperature departure from normal, averaged over September to November 2020. *Temperature normals are based on 1981 to 2010 data.

Long description 

The map of autumn temperature departure from normal (averaged over September to November 2020), shows that:

  • Nearly all areas were above normal by 0.5 °C to 2 °C
  • the highest departures from normal, of 1 °C to 2 °C, were in Prince Edward Island, the southern half of New Brunswick, parts of Nova Scotia, and eastern Massachusetts
  • Northwestern New Brunswick and northern-most Maine were near normal

The scale to the right defines the map colours. Red shades represent positive anomalies (above normal), to +5 °C and above. Blue shades represent negative anomalies (below normal), to -5 °C and below. White indicates near-normal conditions (+0.5 °C to -0.5 °C).

Autumn (averaged over September, October, and November) was up to 2°C (4°F) warmer than normal*. This autumn was among the 10 warmest on record for Caribou and Portland, ME.

September temperatures generally ranged from near normal to 2°C (4°F) above normal, with the warmest spots in New England. Portland, ME, had its seventh-warmest September on record.

October temperatures were within 1°C (2°F) of normal for most areas, with parts of Massachusetts and New Hampshire up to 2°C (4°F) warmer than normal.

November was up to 3°C (5°F) warmer than normal. This November was the warmest on record for Greenwood and Lunenburg, N.S., and among the 10 warmest for Caribou and Portland, ME, and several Maritimes sites.

Daily average temperature departure from normal during autumn at Caribou, ME. Warmer-than-normal days are shaded red and colder-than-normal days are shaded blue.
Long description 

The time series graph displays the daily average temperature departure from normal during autumn (September to November 2020) at Caribou, Maine. It shows:

  • Very warm conditions during the last week of September, the second week of November, and near the end of November, with daily average temperatures as much as 9 °C to 17 °C more than the long term average
  • Temperatures varying above and below normal during the rest of the period, with variations above or below normal of up to about 10 °C

The vertical scale on the right in Celsius ranges from -8 °C to +17 °C (difference from normal), with blue and red shading indicating days with negative and positive departures, respectively.

See table for details:

Daily average temperature departure (°C) from normal for the date, Sept. to Nov. 2020, Caribou, Maine
Day of Month September October November
1 -0.6 4.8 -0.8
2 1.8 0.8 -1.4
3 5.3 0.2 -5.9
4 3.2 -2.4 -7.1
5 0.1 0.1 4.5
6 -1.1 3.1 10.0
7 0.7 5.5 8.6
8 5.6 -1.2 3.8
9 -0.3 -1.8 11.5
10 -1.2 5.8 16.4
11 -1.8 -3.7 14.2
12 -1.1 -3.2 8.3
13 1.9 -1.3 -0.4
14 -1.2 2.2 2.3
15 -3.8 3.6 -1.3
16 1.2 6.2 3.7
17 -2.5 -0.5 -0.8
18 -5.3 0.6 -3.6
19 -3.7 2.9 -5.1
20 -5.2 2.6 3.2
21 -4.1 0.0 3.8
22 -3.3 4.1 -2.1
23 4.4 4.1 3.4
24 2.4 2.8 -2.7
25 -1.0 -3.6 -4.4
26 4.5 -5.3 0.3
27 8.9 -3.2 6.7
28 10.8 -4.1 4.1
29 13.8 -1.7 5.2
30 7.6 -5.1 9.1
31   -5.2  

Precipitation: autumn percent of normal

Autumn precipitation total as a percentage of normal (September to November 2020). U.S. precipitation normals are based on 1981 to 2010 data. Canadian precipitation normals are based on 2002 to 2019 data.
Long description 

The map displays total precipitation as a percentage of normal precipitation over autumn (totalled over September to November 2020). It shows:

  • much drier-than-normal conditions over most of the Maritimes, southern Maine, New Hampshire, and eastern Massachusetts
  • the driest areas, with precipitation as low as half the average amount, over southwestern Nova Scotia, southwestern and southeastern New Brunswick, eastern Prince Edward Island, northern mainland Nova Scotia, and Cape Breton.
  • above-normal to near-normal precipitation amounts over northwestern New Brunswick and northern Maine.

The scale on the right shows above normal (110% of normal and above) in shades of green, below normal (90% of normal and less) in shades of brown, and near normal (90% to 110% of normal) in white.

Autumn precipitation (accumulated from September to November) ranged from 50% of normal to near normal for a majority of the region.

September was dry for most areas, with parts of Maine and western New Brunswick seeing less than 25% of normal precipitation.

In October, southern parts of the Maritimes were dry while northern parts of the Maritimes and New England were wet, with precipitation ranging from 25% of normal to more than 200% of normal.

November precipitation ranged from 25% of normal to near normal for most areas, with the driest spots in western Maine and northern New Hampshire. However, northern Maine was wetter than normal.

Sea Surface Temperature: autumn departure from normal

Sea surface temperature (SST) departure from normal during autumn. SST normals are based on 1985 to 2014 data.
Long description 

The map of sea surface temperature departure from normal, averaged over autumn (September to November 2020), shows that nearly all marine areas of the Gulf of Maine, Bay of Fundy, and waters south of Nova Scotia were warmer than normal. The main text gives more details.

The scale to the right defines the map colours. Red shades represent positive anomalies (above normal), to +3 °C. Blue shades represent negative anomalies (below normal), to -3 °C. White indicates near-normal conditions (departures near 0 °C).

Sea surface temperatures over the entire Gulf of Maine were above normal during autumn. Anomalies were strongest (greater than 2.0°C [4°F]) over the deeper basins of the western Gulf, greater than 1.0°C (2°F) over most of the rest of the region, and weakest over the deeper basins in the eastern Gulf (around 0.5°C [0.9°F]). The entire Bay of Fundy and Scotian Shelf were around 1.0°C (2°F) above normal.

Regional Impacts – September to November 2020

Drought Conditions

During September,drought conditions intensified in New England, with severe to extreme drought in many areas, but some Maritimes locations saw slight improvement. From mid-October through November, conditions improved in some areas.

November 30, 2020 North American Drought Monitor

Long description 

The North American Drought Monitor map for the end of November shows:

  • an area of extreme drought (drought category D3) over southeastern New Hampshire
  • an area of severe drought (drought category D2) over southwestern-most Maine
  • moderate drought (drought category D1) over southeastern New Brunswick, southwestern Nova Scotia, parts of northern Nova Scotia, all of Prince Edward Island, coastal Maine, and much of the rest of New Hampshire
  • abnormal dryness (drought category D0) in locations bordering the areas of moderate drought
  • no drought or abnormal dryness over northern Maine, northwestern New Brunswick, or the eastern shore of Nova Scotia

The letters “SL” on the map over the Maritimes, and over New Hampshire, indicates both short-term impacts (typically <6 months) (for example, agriculture, grasslands) and long-term impacts (>6 months) (for example, hydrology, ecology).

Drought Monitor map categories are as follows:

  • D0 (Abnormally Dry), yellow
  • D1 (Moderate Drought), tan
  • D2 (Severe Drought), orange
  • D3 (Extreme Drought), red
  • D4 (Exceptional Drought), dark red

Agriculture: Forage yields were expected to be reduced by up to 75% in Maine and New Hampshire and up to 50% in the Maritimes. Farmers bought hay to feed livestock, but there were hay shortages and increased prices, with one New Hampshire farmer spending around $14,000 on feed. Potato yields were down by at least 20% in northern Maine and P.E.I. and by as much as 50%  in New Brunswick, meaning revenue losses of up to $50 million. Apples were smaller than usual and yields were down in parts of New England. A Massachusetts farm lost around a third of its Christmas tree saplings. A lack of water presented challenges for cranberry growers, with some losses in Massachusetts. Wild blueberry yields were down in Maine and the Maritimes due to drought and frost. Crop yields were expected to be half of normal in Maine. In New Brunswick, fields that normally yield 8,000 lbs per acre yielded less than 1,000 lbs per acre. New England farmers saw increased expenses due to the drought, with irrigation and labor costs exceeding $50,000 at a Massachusetts farm and around $30,000 at a New Hampshire farm. However, it was a good season for garlic in P.E.I.

Wildfires: New England saw an unusually high number of fires, which burned deeper and took longer to extinguish. Massachusetts had more than 1,000 wildfires as of late September, with 52 fires in a nine-day period from late September to early October. The state’s fire tower network was extended due to increased fire risk. Maine had its worst year for fires in 35 years with 1,150 wildfires as of early December. In New Hampshire, an emergency drought law banning outdoor fires near public woods was in effect for a month, and several communities and the White Mountains National Forest had burn bans. Drought conditions also dried up or reduced water supplies that some firefighters rely on to fight fires. There were 176 fires in Nova Scotia that burned 710 hectares, the highest losses since 2016. In New Brunswick, there have been 462 fires through late November with 1388 hectares burned, well above the 10-year averages of 236 fires and 319 hectares.

Water Resources: The Aroostook River at Washburn and Masardis, ME, dropped to an all-time record-low flow. River levels in the Maritimes hovered near to slightly below historic lows at many locations in the summer and into mid-fall. Water restrictions were in place for hundreds of Massachusetts and New Hampshire locations. Dry wells were reported across New England, including more than 1,000 in New Hampshire, with some well drilling contractors having a waitlist of over 100 people or a 6 to 12 week wait. A lower-than-usual water table helped construction move ahead of schedule along the waterfront in Bangor, ME.

Record-low streamflow along the Aroostook River at Washburn, ME. Photo courtesy: James Sinko.
Long description 

Photograph of record-low streamflow along the Aroostook River at Washburn, ME. It shows 2 bridges crossing the river. There are wide expanses of bare ground or exposed river bottom on each side.

Hurricane season

It was the fifth consecutive year with above-normal tropical activity in the Atlantic Ocean. There were a record-setting 30 named storms of which 13 became hurricanes (second most on record) including six major hurricanes (second most on record). An average season produces 12 named storms of which six become hurricanes including three major hurricanes. In mid-September, there were five tropical systems in the Atlantic at the same time for only the second time on record. The month finished with a record 10 named storms. November had two major hurricanes for the first time on record. Three tropical systems affected the region during summer and another three impacted the region during autumn.

Five named tropical systems in the Atlantic on September 14, 2020. Credit: National Oceanic and Atmospheric Administration (NOAA)
Long description 

Satellite photograph showing 5 named tropical systems in the Atlantic on September 14, 2020. From west to east: Sally (west of Florida), Paulette (east of Cape Hatteras), Rene, Teddy (further south), and Vicky (over the eastern Atlantic).

Hurricane Teddy produced rough surf, minor coastal flooding, and extremely high fire danger due to winds in New England as it moved north in the Atlantic Ocean on September 22. Teddy transitioned into a post-tropical storm before making landfall near Ecum Secum, N.S., on September 23. The storm brought heavy rain, strong winds, and pounding surf to the Atlantic coast of Nova Scotia. Offshore buoys recorded significant wave heights of up to 12 m (39 ft.), with peak waves of up to 25 m (82 ft.), while the Halifax buoy had significant wave heights of up to 5 m (16 ft.) with a peak of 7 m (23 ft.). The greatest rain totals ranged from around 80 to 125 mm (3 to 5 in.). Wind gusts of up to 100 km/h (62 mph) were recorded in Nova Scotia, with the highest gust of 119 km/h (74 mph) at Eskasoni. The strong winds caused power outages throughout the Maritimes. Crop damage was generally localized, with some apple orchards in Nova Scotia losing around 10% of their apples.

A storm system associated with the remnants of Hurricane Delta produced up to 102 mm (4 in.) of rain in the region, with the greatest amounts in New England, from October 12 to 14. Caribou, ME, had its largest two-day precipitation total since October 2017.

On October 30, the remnants of Tropical Storm Zeta brought up to 16.5 cm (6.5 in.) of snow to New England. The greatest amounts were in eastern Massachusetts, where branches and wires were downed due to the weight of the snow. Boston, MA, had its snowiest October and snowiest October day on record. Combined with late spring snowfall, Boston tied its shortest time between measurable snowfalls on record, at 194 days (April 18 to October 30).

Regional outlook – Winter 2020-2021

Temperature and precipitation

Forecast probability of temperature above normal for December 2020 to February 2021. U.S. Climate Prediction Center (CPC) temperature map (left) produced November 19 (left). ECCC temperature map (right) produced November 30.
Long description 

Maps of probability of above-normal temperatures for winter (averaged over December 2020 to February 2021) for New England (left) and the Maritimes (right).
The forecast for the winter season is for warmer than normal conditions over all areas, with high confidence.

For December to February, NOAA's Climate Prediction Center (CPC) and Environment and Climate Change Canada (ECCC)  favour increased chances of above-normal temperatures for the Gulf of Maine region.

The precipitation outlook from ECCC favours above-normal precipitation for the Maritimes for December to February. There is an increased likelihood of above-normal precipitation for northern New Hampshire for December to February, according to CPC. Equal chances of below-, near-, or above-normal precipitation were forecast for the rest of New England.


Climate Prediction Center (CPC) drought map produced December 17.
Long description 

Seasonal drought outlook for New England. The map shows only southern New Hampshire and southern-most Maine still possibly affected by drought.
In those areas, the map shows two categories of possibility:

  • drought removal likely
  • drought remains but improves.

NOAA's Climate Prediction Center indicates that drought conditions are expected to ease in New England between December 17, 2020 and March 31, 2021. The exception is southeastern New Hampshire, where drought conditions are expected to improve but linger. The forecast is based on current La Niña conditions, which tends to shift the storm track toward interior New England.

La Niña

Early-December 2020 official probabilistic El Niño Southern Oscillation (EÑSO) forecasts, issued by the U.S. Climate Prediction Center (CPC) and the International Research Institute (IRI) for Climate and Society.
Long description 

The time series graph shows the forecast probabilities of El Niño, La Niña, and Neutral conditions through the next 12 months, as well as the climatological probabilities, produced in early December 2020.

The chart shows that the probability of La Niña conditions is very high for winter. Neutral conditions become most probable by summer.

Vertical bars represent the forecast probabilities. Lines represent the climatological probabilities. The colours blue, grey, and red, represent La Niña, Neutral, and El Niño conditions, respectively. Each bar represents probabilities over 3 months. Each interval overlaps by 2 months.

The table below gives the forecast probabilities of La Niña, Neutral, and El Niño conditions for each 3-month interval.

Official ENSO forecast probabilities (as a percentage (%))

Season La Niña Neutral El Niño
NDJ 2020 100 0 0
DJF 2021 100 0 0
JFM 2021 95 5 0
FMA 2021 85 15 0
MAM 2021 68 32 0
AMJ 2021 48 50 2
MJJ 2021 34 59 7
JJA 2021 27 57 16
JAS 2021 28 51 21

The climatological probabilities of La Niña, Neutral, and El Niño conditions (solid lines) are as follows:

  • La Niña: about 35% in the winter, 25% in the spring, and 25% in the summer
  • Neutral: about 30% in the winter, 55% in the spring, and 50% in the summer
  • El Niño: about 35% in the winter, 20% in the spring, and 25% in the summer

During November, La Niña conditions persisted in the equatorial Pacific Ocean. NOAA's Climate Prediction Center indicates there is a 95% chance La Niña will continue through winter and around a 50% chance of ENSO-neutral conditions during spring 2021. This La Niña is expected to be moderate strength.


Environment and Climate Change Canada
Email : ec.enviroinfo.ec@canada.ca

National Oceanic and Atmospheric Administration

Northeast Regional Climate Center

Name: Ellen Mecray
Email: Ellen.L.Mecray@noaa.gov
Name: Samantha Borisoff
Email: sgh58@cornell.edu

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