Climate and monthly weather forecastSouth Portland, ME
Climate and monthly weather forecast
The climate of South Portland
South Portland, Maine is situated in a climatic region identified by Köppen's climate classification as Dfb. This classification denotes a humid continental climate, characterized by no dry season and a warm summer. Unpacking weather data reveals a strong annual variation in weather conditions, dictated by this climate type.Temperatures in South Portland illustrate this variation clearly. In the coldest month of February, the average low descends to 20.7°F (-6.3°C), while the highs might only reach 32.5°F (0.3°C). The situation contrasts sharply with July, the warmest month, where temperatures can climb from a low of 62.2°F (16.8°C) to a high of 72.5°F (22.5°C). Seasons in South Portland therefore advance, switching from stark, frigid winter cold to a moderate, welcoming summer warmth.
When it comes to precipitation, South Portland follows a consistent pattern throughout the year. Every month will have its share of rainfall, varying from 1.34" (34mm) in January to a peak of 2.36" (60mm) in October. Conversely, snowy conditions are confined to the period from November to April, with February experiencing the most snowfall at 2.91" (74mm).
The daylight hours follow a predictable pattern of extending from 9.4 hours in January to a lengthy 15.4 hours in June, before retreating again. Sunshine hours rise and fall in tandem, maxing out at 10.7 hours in August.
The unique patterns and variations in South Portland’s weather are epitomized in the climate’s humidity. With humidity levels hovering around 80% throughout the year, a consistent backdrop of moist air is present, shaping weather and its manifestation in South Portland.
The best time to visit South Portland
Considering all climatic features, the period between June and August appears to be the most conducive for visiting South Portland. During this time, the city basks under temperatures ranging from 55°F (12.8°C) to 72.5°F (22.5°C), providing hospitable conditions for outdoor activities and sightseeing. Moreover, with daylight hours exceeding 15 on average, visitors have extended periods to explore and take in the charm of South Portland. Over 10 hours of this can be in vibrant sunshine in July and August, adding further allure to this period.The worst time to visit South Portland
South Portland’s harsh winter culminates in the months of January and February. Throughout this period, average high temperatures fail to surpass the freezing point. The piercing chill is intensified by the prevalent snowy weather, with snowfall reaching 2.91" (74mm) in February. The overcast skies prevalent during these months reduce visibility and diminish the region’s overall appeal for visitors seeking outdoor activities. Hence, planning a trip during this time should be avoided, unless winter-related pursuits are the focus.Spring weather in South Portland
Between March to May, South Portland strides from winter’s end into the welcoming arms of spring. Temperature courses upward, beginning with an average high of 38.3°F (3.5°C) in March and ending spring by touching a pleasant 57.4°F (14.1°C) in May. Simultaneously, the average low climbs from 28.4°F (-2°C) to 46.9°F (8.3°C). The city also starts receiving more sunshine with 8.1 hours per day in April, leading to longer days with up to 14.7 hours of daylight in May. Rainfall is generally consistent during this time varying between 1.73" (44mm) to 1.85" (47mm) monthly.Summer weather in South Portland
Summers in South Portland, from June to August, are temperate and delightful. Average temperatures range from 55°F (12.8°C) to 72.5°F (22.5°C), creating ideal conditions for outdoor activities. This period also experiences the longest days of the year, with daylight hours stretching up to an extensive 15.4 hours in June. Despite featuring the maximum rainfall of 2.2" (56mm) in August, the city welcomes this season with sunshine hours peaking at 10.7 in August.Autumn weather in South Portland
The months of September through November mark the transition from summer to winter. In this interval, average temperatures decline from a high of 66.4°F (19.1°C) in September to a lower 46°F (7.8°C) in November, while night temperatures drop from 56.3°F (13.5°C) to a cooler 37.2°F (2.9°C). A steady presence of rainfall persists throughout this season, reaching a peak of 2.36" (60mm) in October.Winter weather in South Portland
Winter in South Portland comes with a pronounced decrease in temperature. December marks the beginning of this transition, with temperature subsiding from a high of 36.5°F (2.5°C) to a low of 27.9°F (-2.3°C) by February. Snowfall becomes a regular occurrence, especially between January and February, causing a beautiful snow-laden landscape. However, daylight dwindles, with December experiencing only 9 hours and limited sunshine hours of around 5. On the other hand, humidity least affects the city during this season, standing at 74% and 77% in November and December respectively.Weather in January
South Portland weather emits winter chills in January. The city's low of 20.7°F (-6.3°C) brings frosty mornings, and snowy weather remains steadfast with a total snowfall of 2.8" (71mm). Mid-month, skies tend to remain overcast with a cloud cover of approximately 45% on most days. Weather in January »Weather in February
South Portland shifts to February with temperatures slightly milder than January, offering a bit more thaw to the snowy landscape. The freezing grip loosens slightly, and snowfall decreases to 2.91" (74mm). Strong winds continue to sweep across the city, causing wind chills to often feel more profound than the actual temperature. Weather in February »Weather in March
March in South Portland brings hope for the end of the cold season, as warmer temperatures start to settle in. The city's climate starts to transform, with a considerable leap from February's low of 21.6°F (-5.8°C) to a much appreciated 28.4°F (-2°C). Weather in March »Weather in April
April's arrival greets South Portland with noticeable signs of spring. A sudden rise in temperature enhances the blooming of nature as the city's weather evolves from 38.1°F (3.4°C) in March to a promising 47.8°F (8.8°C). The sight of snow becomes uncommon, replaced more often by rainfall with nature responding in kind. Weather in April »Weather in May
May brings delightful weather to South Portland as spring flourishes across the city. Temperatures rise to 57.4°F (14.1°C) ushering in warmer days, though rainfall remains quite consistent with 1.85" (47mm). As the scenery turns lush with bright green foliage, the city starts to resonate with spring's charm. Weather in May »Weather in June
June marks the start of summer in South Portland with its quintessential character. With the city heating up to reach a consistent high of 64.9°F (18.3°C), people start seeking solace near the cool sea waters. The city sees a slight increase in humidity, making the air feel thick at times. Weather in June »Weather in July
In South Portland, July witnesses the warmest weather. As temperatures peak to a summertime high of 72.5°F (22.5°C), the city truly embraces the season. Riding on the summer heat, the sea's temperature jumps to 61.3°F (16.3°C), attracting beach-goers and water enthusiasts. Weather in July »Weather in August
August continues July's warmth in South Portland, with temperatures holding well onto the 70s°F mark. While nights are a bit cooler than the peak summer month, the change is hardly noticeable. With humidity levels slightly reduced compared to the previous month, outdoor activities remain comfortable. Weather in August »Weather in September
September introduces autumn to South Portland with noticeable changes in weather patterns. Taking a cue from August's end, temperatures begin to cool with the average high coming down to 66.4°F (19.1°C). The city starts its gradual transformation into the fall palette, replacing green leaves with shades of red, orange, and yellow. Weather in September »Weather in October
October brings the signature chills of fall to South Portland, making the city's landscape vibrant with colors. As temperatures further decrease settling at an average high of 56.3°F (13.5°C), signs of winter lurking in the corners become evident. Weather in October »Weather in November
November in South Portland witnesses a sharp contrast from the fall hues to a wintery ambiance. The cooler weather engulfs the city as temperatures dip further to an average low of 37.2°F (2.9°C). The picturesque cityscape starts to gradually get adorned with the white cover of the first snowfalls, amounting to about 0.94" (24mm). Weather in November »Weather in December
December wraps up the year in South Portland with the full swing of the winter season. Amid cold spells, temperatures averaging at 36.5°F (2.5°C) define the city's snowy landscape. The city wears a tranquil blanket of white, with 2.28" (58mm) of snowfall adorning the scenery. 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
January, marked by an average high-temperature of 31.1°F (-0.5°C) and a low-temperature of 20.7°F (-6.3°C), is the coldest month in South Portland.
Throughout the year, in South Portland, there are 127 rainfall days, and 21.93" (557mm) of precipitation is accumulated.
January through April, October through December are months with snowfall.
Throughout the year, there are 29.7 snowfall days, and 11.73" (298mm) of snow is accumulated.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in South Portland.
February is the month with the most snowfall in South Portland. Snow falls for 6.8 days and accumulates 2.91" (74mm) of snow.
With an average ocean temperature of 37.9°F (3.3°C), March is the month with the coldest seawater.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.
In South Portland, Maine, snow does not fall in May through September.
The months with the highest humidity in South Portland, Maine, are June and July, with an average relative humidity of 82%.
With an average of 15h and 24min of daylight, June has the longest days of the year in South Portland.
The months with the highest UV index are June through August, with an average maximum UV index of 5.
July, having an average high-temperature of 72.5°F (22.5°C) and an average low-temperature of 62.2°F (16.8°C), is the warmest month in South Portland.
With an average ocean temperature of 63.9°F (17.7°C), August is the month with the warmest seawater.
The month with the most sunshine in South Portland, Maine, is August, with an average of 10.7h of sunshine.
The month with the least rainfall in South Portland is September, when the rain falls for 10.2 days and typically collects 1.18" (30mm) of precipitation.
The month with the most rainfall in South Portland is October, when the rain falls for 11.5 days and typically aggregates up to 2.36" (60mm) of precipitation.
November is the least humid month in South Portland, with an average relative humidity of 74%.
December has the shortest days of the year, with an average of 9h and 0min of daylight.
The month with the least sunshine in South Portland is December, with an average of 4.8h of sunshine.
Average temperature
South 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
South 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
South 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
South 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
South 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
South 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
South 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
South 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
South 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
South Portland, ME
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 30min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 30min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 24min
- Average daylight in July:
15h and 6min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - 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 12min - Average sunshine in February:
4h and 54min - Average sunshine in March:
5h and 54min - Average sunshine in April:
8h and 6min - Average sunshine in May:
8h and 24min - Average sunshine in June:
9h and 6min
- Average sunshine in July:
10h and 18min - Average sunshine in August:
10h and 42min - Average sunshine in September:
8h and 42min - Average sunshine in October:
6h and 18min - Average sunshine in November:
5h and 24min - Average sunshine in December:
4h and 48min
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
South 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
South 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
South 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
South 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).
