Portland
Maine, USA
Long-term weather forecast
Long-term weather forecast

January weather forecast and climate
Portland, ME

Dusk view of the lit skyscrapers of the Portland city in Maine
Dusk view of the lit skyscrapers of the Portland city in Maine
January, like December, is another subzero cold winter month in Portland, Maine, with average temperature varying between 13.5°F (-10.3°C) and 31.3°F (-0.4°C).

Temperature

January is the coldest month, with an average high-temperature of 31.3°F (-0.4°C) and an average low-temperature of 13.5°F (-10.3°C).

Humidity

In Portland, the average relative humidity in January is 66.8%.

Rainfall

In January, in Portland, Maine, the rain falls for 11.1 days. Throughout January, 3.4" (85.9mm) of precipitation is accumulated. Throughout the year, in Portland, there are 130.9 rainfall days, and 47.3" (1200.3mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Portland, Maine, are January through April, November and December. January is the month with the most snowfall. Snow falls for 7.9 days and accumulates 19.2" (487.7mm) of snow.

Ocean temperature

In January, the average ocean temperature is 41.4°F (5.2°C).
Note: Swimming in 41.4°F (5.2°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

Daylight

In January, the average length of the day in Portland is 9.4h.

Sunshine

The average sunshine in January is 5.3h.

UV index

January and December, with an average maximum UV index of 1, are months with the lowest UV index in Portland, Maine. A UV Index estimate of 2, and below, represents a minimal health hazard from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The average daily UV index of 1 transform into the following instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the coldest month in Portland?

The coldest month in Portland is January, with an average high-temperature of 31.3°F (-0.4°C) and an average low-temperature of 13.5°F (-10.3°C).

What is the temperature in January in Portland?

In Portland, in January, the average high-temperature is 31.3°F (-0.4°C), and the average low-temperature is 13.5°F (-10.3°C).

What is the average humidity in January in Portland?

In Portland, Maine, the average relative humidity in January is 66.8%.

How much does it rain in Portland in January?

In Portland, in January, it is raining for 11.1 days, with typically 3.4" (85.9mm) of accumulated precipitation.

How much does it snow in Portland in January?

In Portland, in January, snow falls for 7.9 days, with typically accumulated 19.2" (487.7mm) of snow.

What is the snowiest month in Portland?

The month with the most snowfall in Portland is January when snow falls for 7.9 days and typically aggregates up to 19.2" (487.7mm) of snow.

What is the ocean temperature in January in Portland?

In Portland, in January, the average water temperature is 41.4°F (5.2°C). Swimming in 41.4°F (5.2°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in January in Portland?

In Portland, Maine, the average length of the day in January is 9.4h.

How many hours of sunshine does Portland have in January?

In January, the average sunshine in Portland, Maine, is 5.3h.

What is the month with the lowest UV index in Portland?

January and December, with an average maximum UV index of 1, are months with the lowest UV index in Portland, Maine.

How high is the UV index in January in Portland?

In January, the average daily maximum UV index is 1. A UV Index estimate of 2, and below, represents a low health risk from the exposure to the Sun's UV rays.
Average temperature in January - Portland, ME
  • Average high temperature in January: 31.2°F

The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is January (31.2°F).

  • Average low temperature in January: 13.4°F

The month with the highest average low temperature is July (59.4°F).
The coldest month (with the lowest average low temperature) is January (13.4°F).

Average humidity in January - Portland, ME
  • Average humidity in January: 66.8%

The month with the highest relative humidity is September (76.7%).
The month with the lowest relative humidity is February (65.2%).

Average rainfall in January - Portland, ME
  • Average rainfall in January: 3.4"

Wettest months (with the highest rainfall) are October and November (4.9").
The driest month (with the lowest rainfall) is August (3.1").

Average rainfall days in January - Portland, ME
  • Average rainfall days in January: 11.1 days

The month with the highest number of rainy days is May (12.6 days).
The month with the lowest number of rainy days is September (9.2 days).

Average snowfall in January - Portland, ME
  • Average snowfall in January: 19.2"

The month with the highest snowfall is January (19.2").
Months with the lowest snowfall are May, June, July, August, September and October (0").

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

The month with the highest number of snowfall days is January (7.9 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in January - 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 - Portland, ME
  • Average daylight in January: 9.4h

The month with the longest days is June (Average daylight: 15.4h).
The month with shortest days is December (Average daylight: 9h).

  • Average sunshine in January: 5.3h

The month with most sunshine is July (Average sunshine: 9.1h).
The month with least sunshine is December (Average sunshine: 4.5h).

Average UV index in January - Portland, ME
  • Average UV index in January: 1

Months with the highest UV index are June and July (UV index 8).
Months with the lowest UV index are January and December (UV index 1).