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Contents
- The climate of Portland
- The best time to visit Portland
- The worst time to visit Portland
- Spring weather in Portland
- Summer weather in Portland
- Autumn weather in Portland
- Winter weather in Portland
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average sea temperature
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Dusk view of the lit skyscrapers of the Portland city in Maine
The climate of Portland
Situated in the northeastern part of the United States, Portland, Maine, demonstrates a predominantly Dfb - Humid continental climate, according to the Köppen climate classification. The weather patterns and conditions throughout the year are varied and dynamic in nature. The general weather trends throughout the year are signified by changeable temperatures, perceivable seasonal shifts, considerable precipitation in the form of both rain and snow, and consistent humidity.
From a thermic perspective, Portland experiences considerable fluctuations in temperature. In the warmer months of July and August, average highs reach 72.5°F (22.5°C) and 72.3°F (22.4°C) respectively, while in the colder months of January and February, average lows tumble to 20.7°F (-6.3°C) and 21.6°F (-5.8°C) respectively. The city's humidity remains fairly steady throughout the year, hovering around the high 70% to low 80% mark.
Analysing the precipitation patterns, it is evident that Portland undergoes a noteworthy amount of rainfall every month, ranging from 1.18" (30mm) to 2.36" (60mm). The city also sees periods of snowfall, especially during the winter months from December to February, with snowfall measurements ranging from 2.28" (58mm) to 2.91" (74mm). Seaside life in Portland can be showcased by its sea temperatures, peaking at 63.7°F (17.6°C) in August and dipping to a chilling 38°F (3.3°C) in March.
From a thermic perspective, Portland experiences considerable fluctuations in temperature. In the warmer months of July and August, average highs reach 72.5°F (22.5°C) and 72.3°F (22.4°C) respectively, while in the colder months of January and February, average lows tumble to 20.7°F (-6.3°C) and 21.6°F (-5.8°C) respectively. The city's humidity remains fairly steady throughout the year, hovering around the high 70% to low 80% mark.
Analysing the precipitation patterns, it is evident that Portland undergoes a noteworthy amount of rainfall every month, ranging from 1.18" (30mm) to 2.36" (60mm). The city also sees periods of snowfall, especially during the winter months from December to February, with snowfall measurements ranging from 2.28" (58mm) to 2.91" (74mm). Seaside life in Portland can be showcased by its sea temperatures, peaking at 63.7°F (17.6°C) in August and dipping to a chilling 38°F (3.3°C) in March.
The best time to visit Portland
The ideal time for visiting Portland largely depends on the preferences and activities of the visitor. However, bearing weather conditions into consideration, the summer months from June to August offer the most pleasant, averaging temperatures from 57.4°F (14.1°C) to 72.5°F (22.5°C). During this period, the relative humidity is consistent at 82%, and there are plenty of sunny hours (from 9.1h in June up to 10.7h in August) which are perfect for outdoor activities.
The worst time to visit Portland
Visitors may find that Portland's weather is least desirable during the winter months, specifically between December and February. During this stretch, city experiences its lowest temperatures, plunging to an average low of 20.7°F (-6.3°C) in January. Additionally, these months see the most snowfall, sometimes up to 2.91" (74mm) in February, creating difficult conditions for travel and outdoor activities.
Spring weather in Portland
Portland's springtime, particularly during March, April, and May, witnesses a transition in weather conditions. Average temperature highs rise gradually from 38.3°F (3.5°C) in March to 57.4°F (14.1°C) in May, whereas temperature lows also increase progressively from 28.4°F (-2°C) to 46.9°F (8.3°C) in the same period. Rainfall volumes amplify from 1.73" (44mm) in March to 2.13" (54mm) in June, with May also observing a significant increased number of rainy days (13.2 days). Concurrently, the sea remains relatively cold, slowly warming from 38°F (3.3°C) to 46.7°F (8.2°C).
Summer weather in Portland
Summertime in Portland is characterized by warm temperatures, higher humidity, and increased sunshine hours. From June to August, the average temperature swings from a high of 64.9°F (18.3°C) to 72.5°F (22.5°C), and a low of 55°F (12.8°C) to 62.2°F (16.8°C). Rainfall dips slightly during these months, with the highest average seen in June at 2.13" (54mm). The sea temperature verges on a balmy 63.7°F (17.6°C) by August, making it a great time for water-based activities.
Autumn weather in Portland
Autumn sees cooler temperatures, shorter days and increased precipitation. In September, October, and November, the average high temperature fluctuates from 66.4°F (19.1°C) to 46°F (7.8°C), while the low drops from 56.3°F (13.5°C) to 37.2°F (2.9°C). Rainfall climbs to its yearly peak of 2.36" (60mm) in October. The sea temperature decreases progressively from 60.5°F (15.8°C) in September to 49.6°F (9.8°C) by November.
Winter weather in Portland
Winter in Portland, from December to February, can be intense, with cold temperatures, snowfall, and restricted daylight hours. Average high temperatures stick around 36.5°F (2.5°C) in December and drop to 31.1°F (-0.5°C) by January. Expected low temperatures hover around freezing, occasionally dipping below to 20.7°F (-6.3°C) in January. Snowfall becomes common place, with January witnessing a sizeable amount of 2.91" (74mm). The sea temperatures are also the coldest during these months, often dropping below freezing to a low of 38°F (3.3°C) in February.
Weather in January
Delving into the start of a new year, Portland, Maine experiences the coldest temperatures within the entire calendar year. Notably, the city expects to see from 20.7°F (-6.3°C) to 31.1°F (-0.5°C). The weather usually showcases blankets of snow decorating the surroundings. Weather in January »
Weather in February
Portland, Maine weather in February has similar characteristics as in January, with icy temperatures and frequent snowfall. An increase in temperature occurs from 21.6°F (-5.8°C) to 32.5°F (0.3°C) but snowfall decreases to 2.91" (74mm). Weather in February »
Weather in March
As the month rolls into March, signs of spring finally start to come to the surface. The climate warms up, with temperatures escalating from 28.4°F (-2°C) to 38.3°F (3.5°C). One can anticipate Portland, Maine to witness the charm of spring blossoming slowly but steadily. Weather in March »
Weather in April
Portland sees a significant shift in weather patterns during April. The city warms up to a comfortable range from 38.1°F (3.4°C) to 47.8°F (8.8°C). Spring truly onsets during this period, filling the city with vibrancy and life. Weather in April »
Weather in May
May brings about warmer temperatures, making it an enjoyable precursor to the summer. The mercury rises, hitting between 46.9°F (8.3°C) and 57.4°F (14.1°C). Portland, Maine in May experiences the city blossoming into a plethora of colors brought about by the blooming flora. Weather in May »
Weather in June
In June, Portland preps up for the peak of summer. Temperatures increase significantly, reaching from 55°F (12.8°C) up to 64.9°F (18.3°C). Music fills the air as the city hosts various music festivals, bathing in the welcomed warmth. Weather in June »
Weather in July
July in Portland, Maine can be quite an eventful time with the weather reaching its zenith. The highest temperature spikes can be expected in July, rising from 62.2°F (16.8°C) to 72.5°F (22.5°C). The city enjoys plenty of sunshine and clear skies, making it a popular period for vacationers aiming for that perfect summer break. Weather in July »
Weather in August
August carries forward the summer vibe of July into its weather patterns. The month witnesses temperature ranges near its annual high, sitting between 61.9°F (16.6°C) and 72.3°F (22.4°C). The Portland community organizes the 'Jazz in the Park' series amidst the sunny weather. Weather in August »
Weather in September
With September, the city of Portland starts transitioning from summer to fall. It experiences temperatures ranging from 56.3°F (13.5°C) to 66.4°F (19.1°C). The city embarks on the journey of seeing the leaves change their clothes from green to brown. Weather in September »
Weather in October
October allows Portland to fully embrace fall, with temperatures dropping from 47.5°F (8.6°C) to 56.3°F (13.5°C). The weather is comfortably cool, painting a beautifully rustic picture of the city. Portland's surroundings can boast of a beautiful palette of fall colors during this month. Weather in October »
Weather in November
The month of November brings about a more significant drop in temperature, ranging from 37.2°F (2.9°C) to 46°F (7.8°C). Portland, Maine gears up for the incoming winter season. The trees shed their leaves, making a crunchy carpet underfoot as the city reflects a more desolate yet serene atmosphere. Weather in November »
Weather in December
Coming to the end of the year, Portland, Maine experiences significant drops in temperature, ranging from 36.5°F (2.5°C) to 27.9°F (-2.3°C). December sees an introduction of snowy landscapes painting the city white. Christmas lights twinkle, and holiday decorations spruce up the city, lifting spirits despite the chill. Weather in December »
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year in Portland?
Portland's January weather, marked by an average high temperature of 31.1°F (-0.5°C) and an average low temperature of 20.7°F (-6.3°C), is the coldest in the year.
How many days does it rain in Portland?
Throughout the year, in Portland, Maine, there are 127 rainfall days, and 21.93" (557mm) of precipitation is accumulated.
When does it snow in Portland?
Months with snowfall are January through April, October through December.
How much does it snow in Portland?
Throughout the year, in Portland, Maine, there are 29.7 snowfall days, and 11.73" (298mm) of snow is accumulated.
When is the lowest UV index in Portland?
The months with the lowest UV index in Portland are January through March, November and December, with an average maximum UV index of 2.
When does it snow the most in Portland?
February is the month with the most snowfall in Portland. Snow falls for 6.8 days and accumulates 2.91" (74mm) of snow.
What month is the ocean coldest in Portland?
With an average ocean temperature of 37.9°F (3.3°C), March is the month with the coldest seawater in Portland.
When is Daylight Saving Time (DST) in Portland?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Portland, Maine, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
When it does not snow in Portland?
In Portland, snow does not fall in May through September.
What are the most humid months in Portland?
June and July, with an average relative humidity of 82%, are most humid months in Portland.
When are the longest days in Portland?
With an average of 15h and 24min of daylight, June has the longest days of the year in Portland.
What is the month with the highest UV index in Portland?
The months with the highest UV index are June through August, with an average maximum UV index of 5.
What is the warmest month in Portland?
July is Portland's warmest month, registering average high temperatures of 72.5°F (22.5°C) and lows of 62.2°F (16.8°C).
When is the ocean warmest in Portland?
The month with the warmest seawater is August, with an average ocean temperature of 63.9°F (17.7°C).
What month has the most sunshine in Portland?
The month with the most sunshine is August, with an average of 10.7h of sunshine.
What is the driest month in Portland?
September is the month with the least rainfall in Portland. Rain falls for 10.2 days and accumulates 1.18" (30mm) of precipitation.
What is the rainiest month in Portland?
October is the month with the most rainfall in Portland. Rain falls for 11.5 days and accumulates 2.36" (60mm) of precipitation.
What is the least humid month in Portland?
The least humid month in Portland, Maine, is November, with an average relative humidity of 74%.
What is the month with the shortest days in Portland?
December has the shortest days of the year in Portland, with an average of 9h and 0min of daylight.
What is the month with the least sunshine in Portland?
December has the least sunshine of the year, with an average of 4.8h of sunshine.
Average temperature
Portland, ME
The warmest month (with the highest average high temperature) is July (72.5°F).
The month with the lowest average high temperature is January (31.1°F).
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure
Portland, ME
- Average pressure in January:
29.98"Hg - Average pressure in February:
29.97"Hg - Average pressure in March:
30.02"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
29.99"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.93"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.05"Hg - Average pressure in December:
30.01"Hg
The months with the highest atmospheric pressure are September and November (30.05"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Portland, ME
- Average wind speed in January:
12.5mph - Average wind speed in February:
11.9mph - Average wind speed in March:
11.7mph - Average wind speed in April:
10.4mph - Average wind speed in May:
9mph - Average wind speed in June:
8.3mph
- Average wind speed in July:
7.5mph - Average wind speed in August:
7.5mph - Average wind speed in September:
8.5mph - Average wind speed in October:
10.4mph - Average wind speed in November:
11.2mph - Average wind speed in December:
11.6mph
The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest months (with the lowest average wind speed) are July and August (7.5mph).
Average humidity
Portland, ME
The months with the highest relative humidity are June and July (82%).
The month with the lowest relative humidity is November (74%).
Average rainfall
Portland, ME
- Average rainfall in January:
1.34" - Average rainfall in February:
1.54" - Average rainfall in March:
1.73" - Average rainfall in April:
2.05" - Average rainfall in May:
1.85" - Average rainfall in June:
2.13"
- Average rainfall in July:
1.85" - Average rainfall in August:
2.2" - Average rainfall in September:
1.18" - Average rainfall in October:
2.36" - Average rainfall in November:
1.69" - Average rainfall in December:
2.01"
The wettest month (with the highest rainfall) is October (2.36").
The driest month (with the least rainfall) is September (1.18").
Average rainfall days
Portland, ME
- Average rainfall days in January:
5.7 days - Average rainfall days in February:
5.8 days - Average rainfall days in March:
9.3 days - Average rainfall days in April:
13.2 days - Average rainfall days in May:
13.2 days - Average rainfall days in June:
13.2 days
- Average rainfall days in July:
14.7 days - Average rainfall days in August:
13.4 days - Average rainfall days in September:
10.2 days - Average rainfall days in October:
11.5 days - Average rainfall days in November:
8.9 days - Average rainfall days in December:
7.9 days
The month with the highest number of rainy days is July (14.7 days).
The month with the least rainy days is January (5.7 days).
Average snowfall
Portland, ME
The month with the highest snowfall is February (2.91").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Portland, ME
- Average snowfall days in January:
7.9 days - Average snowfall days in February:
6.8 days - Average snowfall days in March:
5.8 days - Average snowfall days in April:
1.6 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.1 days - Average snowfall days in November:
2.1 days - Average snowfall days in December:
5.4 days
The month with the highest number of snowfall days is January (7.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature
Portland, ME
The best month for swimming (with the highest average sea temperature) is August (63.7°F).
The coldest month (with the lowest average sea temperature) is March (38°F).
Average daylight / Average sunshine
Portland, ME
- Average daylight in January:
9h and 2min - Average daylight in February:
10h and 3min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 3min - Average daylight in May:
14h and 4min - Average daylight in June:
15h and 2min
- Average daylight in July:
15h and 1min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 4min - Average daylight in December:
9h and 0min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in January:
5h and 1min - Average sunshine in February:
4h and 5min - Average sunshine in March:
5h and 5min - Average sunshine in April:
8h and 1min - Average sunshine in May:
8h and 2min - Average sunshine in June:
9h and 1min
- Average sunshine in July:
10h and 2min - Average sunshine in August:
10h and 4min - Average sunshine in September:
8h and 4min - Average sunshine in October:
6h and 2min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).
Average sunshine days
Portland, ME
- Average sunshine days in January:
18.8 days - Average sunshine days in February:
16.8 days - Average sunshine days in March:
15.6 days - Average sunshine days in April:
14.3 days - Average sunshine days in May:
16 days - Average sunshine days in June:
15 days
- Average sunshine days in July:
13.8 days - Average sunshine days in August:
14.4 days - Average sunshine days in September:
17.5 days - Average sunshine days in October:
17.4 days - Average sunshine days in November:
19 days - Average sunshine days in December:
17.6 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is July (13.8 days).
Average UV index
Portland, ME
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover
Portland, ME
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility
Portland, ME
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Portland, Maine, USA
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