January weather forecast and climate
Boston, MA

A beautiful natural park with the George Washington Monument in Boston, Massachusetts, with a sneak view of the city skyscrapers
A beautiful natural park with the George Washington Monument in Boston, Massachusetts, with a sneak view of the city skyscrapers
January, like December, in Boston, Massachusetts, is another cold winter month, with average temperature fluctuating between 34.2°F (1.2°C) and 22.6°F (-5.2°C).

Temperature

The coldest month is January, with an average high-temperature of 34.2°F (1.2°C) and an average low-temperature of 22.6°F (-5.2°C).

Humidity

The average relative humidity in January is 76%.

Rainfall

In January, in Boston, Massachusetts, the rain falls for 7.9 days. Throughout January, 2.28" (58mm) of precipitation is accumulated. In Boston, during the entire year, the rain falls for 141.4 days and collects up to 27.2" (691mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. In Boston, during 7.6 snowfall days, 2.76" (70mm) of snow is typically accumulated. Throughout the year, there are 29.8 snowfall days, and 15.75" (400mm) of snow is accumulated.

Ocean temperature

In Boston, Massachusetts, the average seawater 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 Boston, the average length of the day in January is 9.5h.

Sunshine

In Boston, Massachusetts, the average sunshine is 5.1h.

UV index

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Boston. A UV Index reading of 2, and below, represents a minimal health vulnerability from the exposure to the Sun's UV rays for the average person.
Note: In January, the average maximum UV index of 2 translate into the following recommendations:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the coldest month in Boston?

With an average high-temperature of 34.2°F (1.2°C) and an average low-temperature of 22.6°F (-5.2°C), January is the coldest month.

What is the temperature in January in Boston?

In Boston, Massachusetts, in January, the average high-temperature is 34.2°F (1.2°C), and the average low-temperature is 22.6°F (-5.2°C).

What is the average humidity in January in Boston?

The average relative humidity in January in Boston, Massachusetts, is 76%.

How many days does it rain in January in Boston?

In Boston, Massachusetts, in January, during 7.9 rainfall days, 2.28" (58mm) of precipitation is typically accumulated.

How many days does it snow in January in Boston?

In Boston, in January, snow falls for 7.6 days, with typically accumulated 2.76" (70mm) of snow.

What is the water temperature in January in Boston?

In January, the average ocean temperature in Boston is 41.4°F (5.2°C). 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.

How many hours of daylight does Boston have in January?

The average length of the day in January is 9.5h.

How many hours of sunshine does Boston have in January?

In Boston, the average sunshine in January is 5.1h.

What are the months with the lowest UV index in Boston?

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

What is the UV index intensity in January in Boston?

In Boston, Massachusetts, the average daily maximum UV index in January is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health from unprotected exposure to the UV radiation.
Average temperature in January - Boston, MA
  • Average high temperature in January: 1.2°C

The warmest month (with the highest average high temperature) is July (27.6°C).
The month with the lowest average high temperature is January (1.2°C).

  • Average low temperature in January: -5.2°C

The month with the highest average low temperature is July (18.3°C).
The coldest month (with the lowest average low temperature) is January (-5.2°C).

Average pressure in January - Boston, MA
  • Average pressure in January: 1016mbar

The month with the highest atmospheric pressure is November (1018.1mbar).
The month with the lowest atmospheric pressure is June (1013.4mbar).

Average wind speed in January - Boston, MA
  • Average wind speed in January: 15.9km/h

The windiest month (with the highest average wind speed) is January (15.9km/h).
The calmest month (with the lowest average wind speed) is August (9.9km/h).

Average humidity in January - Boston, MA
  • Average humidity in January: 76%

The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (69%).

Average rainfall in January - Boston, MA
  • Average rainfall in January: 58mm

The wettest months (with the highest rainfall) are March, April and December (74mm).
The driest month (with the least rainfall) is September (32mm).

Average rainfall days in January - Boston, MA
  • Average rainfall days in January: 7.9 days

The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.9 days).

Average snowfall in January - Boston, MA
  • Average snowfall in January: 70mm

The month with the highest snowfall is February (120mm).
Months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in January - Boston, MA
  • Average snowfall days in January: 7.6 days

Months with the highest number of snowfall days are January and February (7.6 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in January - Boston, MA
  • Average sea temperature in January: 5.2°C

The best month for swimming (with the highest average sea temperature) is August (20°C).
The coldest month (with the lowest average sea temperature) is February (3.4°C).

Average daylight in January / Average sunshine in January - Boston, MA
  • Average daylight in January: 9.5h

The month with the longest days is June (Average daylight: 15.2h).
The month with the shortest days is December (Average daylight: 9.1h).

  • Average sunshine in January: 5.1h

The month with the most sunshine is August (Average sunshine: 10.5h).
The month with the least sunshine is February (Average sunshine: 4.6h).

Average sunshine days in January - Boston, MA
  • Average sunshine days in January: 17.5 days

The month with the most sunshine days is September (17.7 days).
The month with the least sunshine days is April (13 days).

Average UV index in January - Boston, MA
  • Average UV index in January: 2

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in January - Boston, MA
  • Average cloud cover in January: 45

The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in January - Boston, MA
  • Average visibility in January: 9km

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).