Quarterly climate impacts and outlook for the Gulf of Maine Region: June 2020

Gulf of Maine region significant events – March to May 2020

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The image shows the map of the Gulf of Maine region. It highlights significant weather and climate events that occurred in the months of March to May 2020.

A storm from April 9 to 10 led to widespread power outages, particularly in Maine.

The first half of May was cold with a late-season snowstorm but May ended with record-setting heat.


Storms moved through the region frequently during March. The most notable storm occurred from March 23 to 24 and produced strong winds and a mix of precipitation types. The greatest snow totals of up to 38 cm (15 in.) were in New Hampshire, Maine, and Cape Breton (N.S.), while the greatest rain totals of up to 75 mm (3 in.) were in eastern Massachusetts. There were thousands of power outages in Maine and Nova Scotia. Despite several storms, many areas saw below-normal precipitation and above-normal temperatures.


There were frequent storms again in April. A storm rapidly strengthened to a near-record pressure level for April for Maine, producing wind gusts of up to 108 km/h (67 mph) across the region and dumping heavy snow on parts of Maine, New Hampshire, and New Brunswick, from April 9 to 10. The greatest storm snow totals of up to 53 cm (21 in.) were in Maine, with Caribou seeing 27.7 cm (10.9 in.) of snow, its second snowiest April day on record. In Maine, the heavy, wet snow downed trees and wires, leaving more than 266,000 customers, around a third of the state, without power. In the Maritimes, more than 10,000 customers lost power and blowing snow closed some roads. Storm surge led to road closures, flooded some buildings, damaged a trail and pier in Downeast Maine, and destroyed a historic trail in Saint Andrews, N.B.

From April 12 to 14, a storm brought damaging winds and rain to the region. Wind gusts of 65 to 95 km/h (40 to 60 mph) were common, with a peak gust of 129 km/h (80 mph) in Milton, MA. The strong winds downed trees and wires, leaving more than 115,000 customers in Massachusetts and around 7,000 customers in Nova Scotia without power. The system also produced heavy rain, with the greatest totals of more than 50 mm (2 in.) in coastal Maine and central New Hampshire


High temperatures in New England on May 9 were as much as 14°C (25°F) below normal, with Caribou, ME, having its second coldest max temperature for May. With cold air in place, a nor'easter brought snow to much of the region. The greatest amounts were in northern Maine and New Brunswick, with this ranking among the largest single-day snowfalls for May. Woodstock, N.B., saw 33 cm (13 in.) of snow on May 9, making it the site's snowiest May day since 1886 and beating the old record of 10.2 cm (4 in.) from May 2, 1917. Caribou had its third snowiest May day, while Concord saw measurable snow in May for the first time in over 50 years. Wet snow and strong winds in the Maritimes caused more than 9,500 customers to lose power.

Temperatures were unusually mild from May 27 to 29. On May 28, both Bas Caraquet and Miscou Island, N.B., set monthly maximum temperature records of 33.7°C (93°F) and 32.3°C (90°F), respectively. Caribou's low temperature on May 27 and 28 ranked as the third warmest for May, while its low of 21°C (69°F) on May 29 was record warm for May. Concord recorded its second warmest May minimum temperature. Dozens of daily temperature records were broken in the Maritimes. In addition, Caribou had a dew point of 21°C (70°F) for the first time in May.

Regional climate overview - March to May 2020

Temperature: spring departure from normal

Map of temperature departure from normal, averaged over March to May 2020. Temperature normals are based on 1981 to 2010 data.
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The map of temperature departure from normal, averaged over March to May 2020, shows that most of Gulf of Maine region was within 1° C of normal. Northern Maine, northern New Brunswick, and parts of northern mainland Nova Scotia and Cape Breton were colder than average, by as much as 2° C. Some southern sections of New England were warmer than average by as much as 1° C.

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

Spring temperatures (averaged over March, April, and May) were within 1°C (2°F) of normal for most areas, with parts of the Maritimes being colder and parts of New England being warmer. Portland, ME, had its sixth warmest spring.

March temperatures ranged from near normal in the Maritimes to 3°C (5°F) above normal in New England. Portland had its seventh warmest March and earliest 21°C (70°F) day.

April was as much as 3°C (5°F) colder than normal. The highest temperature reached in April in Boston, MA, and Portland was the coldest for April and second coldest for Concord, NH.

May temperatures were within 1°C (2°F) of normal for many areas but cooler at a few Maritimes sites. Bangor, ME, did not reach 21°C (70°F) until May 7, its third latest date on record.

Daily average temperature departure from normal during spring at Caribou, ME. Warmer-than-normal days are shaded red and colder-than-normal days are shaded blue.
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The time series graph displays the daily average temperature departure from normal during spring (March to May 2020) at Caribou, Maine. It shows:

  • frequent temperature swings above and below normal in March,
  • a period of warmer-than-average days in late March and early April,
  • an extended period of colder-than-normal days in the rest of April and the first half of May
  • a dramatic warming to well-above normal temperatures in the last week of May.

The vertical scale on the right in Celsius ranges from -11° to +14° C.

Precipitation: spring percent of normal

Spring precipitation total as a percentage of normal (March to May 2020). U.S. precipitation normals are based on 1981 to 2010 data. Canadian precipitation normals are based on 2002 to 2019 data.
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The map displays total precipitation as a percentage of normal precipitation over the months of March to May 2020. Conditions were drier than normal over much of the region. Driest areas were southeastern New Brunswick, western and northern mainland Nova Scotia, and Prince Edward Island, which received as little as half the normal amount of total precipitation.

The scale on the right has above normal (110% of normal and above) shown 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.

Spring precipitation (accumulated from March to May) ranged from 50% of normal to 110% of normal for much of the region.

Most areas saw 25% to 110% of normal precipitation in March; however, northern Maine and Cape Breton, N.S., saw up to 175% of normal precipitation. This March was among the 10 driest on record for some sites in New Brunswick and Nova Scotia.

April precipitation ranged from 25% of normal in eastern P.E.I. to 200% of normal in central New Hampshire. Charlottetown and Summerside, P.E.I., had one of their three driest Aprils on record.

May precipitation ranged from 25% to 110% of normal for most areas, except in southern Nova Scotia, which saw up to 150% of normal.

Sea surface temperatures: spring departure from normal

Sea surface temperature (SST) anomalies during spring. SST normals are based on 1985 to 2014 data.
Long description

The map of sea surface temperature departure from normal, averaged over March to May 2020, shows that the Gulf of Maine waters and coastal waters of Nova Scotia were warmer than normal. The text gives more details.

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

Sea surface temperature anomalies during spring over the entire Gulf of Maine were above normal, strongest (around 1.2°C [2.2°F]) in the Bay of Fundy and along the coast of Maine and weaker (0.3 to 0.8°C [0.5 to 1.4°F]) over the deeper basins in the center of the Gulf. Anomalies over the Scotian Shelf were a mix of weak positive (0.4°C [0.7°F]) and weak negative (-0.2°C [-0.4°F]) values.

Spring Snowfall

Left: Snowfall on April 10 in Bangor, ME. Credit: Maura Thomas. Right: Snowfall on May 10 in New Maryland, N.B. Credit: Russell Emery.
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The photo on the left of snowfall on April 10 in Bangor, ME shows snow-covered deciduous trees, some bowed down by the weight of the snow.

The photo on the right of snowfall on May 10 in New Maryland, N.B., shows a back-yard deck and deck table covered in snow.

March snowfall was below normal for most of the region. Boston recorded only a trace of snow during March, tying as the least snowy March on record. However, northern Maine, northwestern New Brunswick, and Cape Breton, N.S., saw more snowfall than usual.

April snowfall was above to much above normal for Maine, northern New Hampshire, and much of the Maritimes, particularly northwestern New Brunswick and Cape Breton, N.S. This April ranked among the 10 snowiest for Sydney, N.S.; Bas Caraquet, N.B.; and Caribou, ME. A storm on April 19 dropped 43 cm (17 in.) of snow in Sydney, N.S., making it the site's second snowiest April day since 1870. Also, Caribou recorded its second longest streak with at least 3 cm (1 in.) of snow depth at 159 days (November 12, 2019 to April 18, 2020). The record of 163 consecutive days was set last year. April snowfall was below normal for parts of mainland Nova Scotia, eastern P.E.I., and southern New Hampshire.

May snowfall was above normal for the Maritimes, Maine, and New Hampshire. Woodstock, N.B., had it snowiest May on record. In fact, the snowfall total in Woodstock, N.B., from the May 9 to 10 storm alone eclipsed the previous highest snow total on record for the entire month, set in 1917. Bas Caraquet, N.B., had its second snowiest May, while Caribou, ME, had its third snowiest and Concord, NH, had its sixth snowiest. Eastern Massachusetts saw near-normal May snowfall.

Spring snowfall was below normal for Massachusetts, most of New Hampshire, southern Maine, southern New Brunswick, much of mainland Nova Scotia, and eastern P.E.I. However, western P.E.I., Cape Breton (N.S.), northern New Brunswick, and northern Maine saw above-normal spring snowfall, with Caribou having its 10th snowiest spring. For the snow season (October through May), Caribou had its sixth snowiest season, while Boston had its eighth least snowy.

 Modeled snow depth on April 1. Credit: NOAA National Operational Hydrologic Remote Sensing Center (NOHRSC).
Long description

The map of modelled snow depth on April 1 shows much of the Maritimes, Maine, and northern New Hampshire covered in snow, with snow depths in northern New Brunswick and Maine of over 50 cm. Southern and coastal areas of New England and the Maritimes show no snow, or snow depths of 5 cm or less.

Regional impacts – March to May 2020

Air Quality

According to NASA, “...the data indicate that the nitrogen dioxide levels in March 2020 are about 30% lower on average across the region of the I-95 corridor from Washington, DC to Boston than when compared to the March mean of 2015-19.” Reduced greenhouse gas emissions this spring were partially attributed to less transportation and industrial output due to stay-at-home orders during the coronavirus outbreak.

Spring Conditions

Spring leaf out occurred more than a week earlier than usual in eastern Massachusetts due in part to mild March conditions; however, colder weather in April and May contributed to leaf out occurring more than a week later than usual for much of Maine, as well as spring bloom occurring later than usual for parts of New England. In the Maritimes, a cool start to May delayed seeding operations and frost affected some fruit trees. Dry conditions in P.E.I. were favorable for planting potatoes with about half the crop planted by late May.

The spring freshet in New Brunswick showed three peaks in water levels (April 8 to 9, April 15 to 17, and May 3 to 8) that caused two sites to go above flood stage along the Saint John River basin; however, no major flooding occurred as in the past two years, which saw record-setting levels. With below-normal spring precipitation, moderate drought and abnormal dryness developed in southeastern New Brunswick, northern Nova Scotia, P.E.I., parts of Maine, southern New Hampshire, and northeastern Massachusetts. Some areas saw increased forest fire activity. Maine saw 55 brush fires during Memorial Day weekend (May 22 to 25), bringing the year-to-date total as of June 2 to 600 fires, more than the state saw in all of 2019. Even with burn bans in place, there were more than 70 fires since May 18 in New Brunswick, with a fire near Blackville being one of the largest fires in the province since the mid-1990s. As of June 3, there were 232 fires with 1120 hectares burned in New Brunswick, well above the 10-year average of 150 fires with 191 hectares burned for the same period. A brush fire at Porters Lake, N.S., led to the evacuation of more than 500 homes and burned about 50 hectares. Ipswich and Georgetown, MA, enacted mandatory water restrictions effective June 1 due in part to below-normal precipitation and below-normal streamflow on the Ipswich and Parker Rivers.

May 31, 2020 North American Drought Monitor.
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The North American Drought Monitor map for the end of May shows an area of moderate drought or abnormally dry conditions in southeastern New Brunswick, western Nova Scotia, and Prince Edward Island. The “S” on the map in the location of moderate drought indicates short-term drought impacts (typically <6 months). Other sections of northern Maine, southern New Hampshire, and eastern Massachusetts were abnormally dry.

May 29, 2020 North American Water Watch streamflow.
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The North American Water Watch stream flow map displays daily streamflow compared to historical streamflows. For the end of May it shows normal flows at sites in the northern half of New Brunswick and parts of northern Maine and New Hampshire. Elsewhere river flows were generally below normal. River flows were much below normal at a few sites in southeastern New Brunswick and southern Maine. In contrast a few sites in western Cape Breton had much above normal stream flows.

Regional outlook – summer 2020

Temperature and precipitation

For June to August, NOAA's Climate Prediction Center (CPC) and Environment and Climate Change Canada (ECCC) favor increased chances of above-normal temperatures for the region.

An increased likelihood of below-normal precipitation is forecast for New Brunswick, northern and western Nova Scotia, and western P.E.I. for June to August. Equal chances of below-, near-, or above-normal precipitation were predicted for New England and the rest of the Maritimes.

Forecast probability of temperature above normal, period: June to August 2020. U.S. Climate Prediction Center (CPC) temperature map (left) produced May 21. ECCC temperature map (right) produced May 31.
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Map of probability of above-normal temperatures for summer (averaged over June to August 2020) for New England (left) and the Maritimes (right).

The summer months are forecast to be warmer than normal over all areas. Probabilities of above-average temperatures are 60 to 70% for much of New England and 40 to 60% for the Maritimes.

Atlantic Hurricane Season

NOAA's 2020 Atlantic hurricane season outlook indicates an above-normal season is most likely, with “a likely range of 13 to 19 named storms of which 6 to 10 could become hurricanes, including 3 to 6 major hurricanes (Category 3 or higher).” Factors such as a lack of El Niño conditions and warmer-than-normal sea surface temperatures favor increased storm activity. For the sixth consecutive year the season started early, with the first storm forming on May 16, the second storm on May 27, and already the third storm on June 2. The season runs from June 1 through November 30, peaking from mid-August to late October.

Quantity 2020 Atlantic season outlook Average season
Number of named storms 13 to 19 12
Number of hurricanes 6 to 10 6
Number of major hurricanes 3 to 6 3

El Niño/Southern Oscillation (ENSO)

Early-June 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.
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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 June 2020.

In summary, there is about a 60% chance of neutral conditions during summer 2020, with roughly equal chances (40 to 50%) of La Niña or neutral during the autumn and winter 2020 to 2021.

The forecast probabilities are plotted as vertical bars. The climatological probabilities are plotted as lines. 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 first 3-month interval is March-June-July 2020. The fall months of September-October-November 2020 are in the middle of the graph. The last 3-month interval is January-February-March 2021.

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

Season La Niña Neutral El Niño
MJJ 2020 25% 73% 2%
JJA 2020 37% 60% 3%
JAS 2020 44% 52% 4%
ASO 2020 46% 48% 6%
SON 2020 46% 46% 8%
OND 2020 46% 45% 9%
NDJ 2020 to 2021 46% 43% 11%
DJF 2020 to 2021 44% 43% 13%
JFM 2021 42% 42% 16%

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

  • La Niña: about 25% in the spring and summer, increasing to about 35% in the fall and winter
  • Neutral: about 50% in the spring and summer, decreasing to 30% in the winter
  • El Niño: about 25% in the spring and summer, increasing to about 35% in the fall and winter

The EÑSO state is based on NINO3.4 Sea surface temperature (SST) Anomaly. The neutral EÑSO is defined as -0.5° C to 0.5° C.

During May, El Niño-Southern Oscillation (ENSO)-neutral conditions were observed in the equatorial Pacific Ocean. NOAA's Climate Prediction Center indicates there is a 60% chance ENSO-neutral conditions will continue through summer and nearly equal chances (40 to 50%) of ENSO-neutral or La Niña conditions during autumn and winter.


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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