January weather forecast
South Portland, ME

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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. The frigid air and lower sunlight exposure make outdoor activities less inviting. Though short, days remain crisp, reflecting the winter character of Maine.

Temperature

January, with its high-temperature average of 31.1°F (-0.5°C) and a low-temperature average of 20.7°F (-6.3°C), is the coldest month in South Portland.

Humidity

In January, the average relative humidity in South Portland is 79%.

Rainfall

In South Portland, Maine, in January, during 5.7 rainfall days, 1.34" (34mm) of precipitation is typically accumulated. In South Portland, during the entire year, the rain falls for 127 days and collects up to 21.93" (557mm) of precipitation.

Snowfall

January through April, October through December are months with snowfall. In South Portland, Maine, in January, snow falls for 7.9 days, with typically accumulated 2.8" (71mm) of snow. In South Portland, during the entire year, snow falls for 29.7 days and aggregates up to 11.73" (298mm) of snow.

Ocean temperature

In South Portland, Maine, in January, the average water temperature is 41.4°F (5.2°C).
Note: It is risky to swim in 41.4°F (5.2°C). Temperatures beneath 50°F (10°C) induce rapid cold shock and hyperventilation.

Daylight

The average length of the day in January in South Portland is 9h and 23min.
On the first day of January, sunrise is at 7:14 am and sunset at 4:14 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:50 pm EST.

Sunshine

In January, the average sunshine is 5.2h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the average person.
Note: The average daily UV index of 2 in January transforms into the following instructions:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Boost your sun resistance with garments that are densely woven yet spacious. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the coldest in South Portland?

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, Maine.

How cold is January in South Portland?

In South Portland, in January, the average high-temperature is 31.1°F (-0.5°C), and the average low-temperature is 20.7°F (-6.3°C).

What is the average humidity in January in South Portland?

In January, the average relative humidity in South Portland, Maine, is 79%.

How much does it rain in South Portland in January?

In South Portland, during January, the rain falls for 5.7 days and regularly aggregates up to 1.34" (34mm) of precipitation.

How many days does it snow in January in South Portland?

In South Portland, in January, during 7.9 snowfall days, 2.8" (71mm) of snow is typically accumulated.

How cold is the water in January in South Portland?

In January, the average ocean temperature in South Portland is 41.4°F (5.2°C). At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

How many hours of daylight does South Portland have in January?

In South Portland, the average day length in January is 9h and 23min.

What time are sunrise and sunset in January in South Portland?

On the first day of January, sunrise is at 7:14 am and sunset at 4:14 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:50 pm EST.

How many hours of sunshine does South Portland have in January?

In South Portland, Maine, the average sunshine duration in January is 5.2h.

When is the lowest UV index in South Portland?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in South Portland, Maine.

How high is the UV index in January in South Portland?

The average daily maximum UV index in January in South Portland, Maine, is 2. A UV Index value of 2, and less, symbolizes a low health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
South Portland, ME

Average temperature in January - South Portland, ME
  • Average high temperature in January: 31.1°F

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).

  • Average low temperature in January: 20.7°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 in January
South Portland, ME

Average pressure in January - South Portland, ME
  • Average pressure in January: 29.98"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 in January
South Portland, ME

Average wind speed in January - South Portland, ME
  • Average wind speed in January: 12.5mph

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 in January
South Portland, ME

Average humidity in January - South Portland, ME
  • Average humidity in January: 79%

The months with the highest relative humidity are June and July (82%).
The month with the lowest relative humidity is November (74%).

Average rainfall in January
South Portland, ME

Average rainfall in January - South Portland, ME
  • Average rainfall in January: 1.34"

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 in January
South Portland, ME

Average rainfall days in January - South Portland, ME
  • Average rainfall days in January: 5.7 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 in January
South Portland, ME

Average snowfall in January - South Portland, ME
  • Average snowfall in January: 2.8"

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 in January
South Portland, ME

Average snowfall days in January - South Portland, ME
  • Average snowfall days in January: 7.9 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 in January
South Portland, ME

Average sea temperature in January - South Portland, ME
  • Average sea temperature in January: 41.3°F

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 in January /
Average sunshine in January
South Portland, ME

Average daylight in January / Average sunshine in January - South Portland, ME
  • Average daylight in January: 9h and 2min

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

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 in January
South Portland, ME

Average sunshine days in January - South Portland, ME
  • Average sunshine days in January: 18.8 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 in January
South Portland, ME

Average UV index in January - South Portland, ME
  • Average UV index in January: 2

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 in January
South Portland, ME

Average cloud cover in January - South Portland, ME
  • Average cloud cover in January: 45

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 in January
South Portland, ME

Average visibility in January - South Portland, ME
  • Average visibility in January: 6mi

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).

South Portland, Maine, USA

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