January weather - Winter 2025

Weather in January
Frequently asked questions
Average temperature in January
Average pressure in January
Average wind speed in January
Average humidity in January
Average rainfall in January
Average rainfall days in January
Average snowfall in January
Average snowfall days in January
Average sea temperature in January
Average daylight in January
Average sunshine in January
Average sunshine days in January
Average UV index in January
Average cloud cover in January
Average visibility in January

A beautiful natural park with the George Washington Monument in Boston, Massachusetts

Weather in January

The Boston climate in January begins on a chilly note as the new year unfolds. Cold winter conditions govern the area with both high and low temperatures resting between 34.2°F (1.2°C) and 22.6°F (-5.2°C). On average, snowfall occurs for 7.6 days, leaving a total accumulation of 2.76" (70mm). This month's frosty weather dictates the necessity of warm clothing, especially during the evenings. A gentle reminder goes to watch out for slippery surfaces caused by the settled snow.

Temperature

January is the coldest month of the year, registering average temperatures as high as 34.2°F (1.2°C) and as low as 22.6°F (-5.2°C).

Humidity

In January, the average relative humidity in Boston is 76%.

Rainfall

In Boston, in January, during 7.9 rainfall days, 2.28" (58mm) of precipitation is typically 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 January, snow falls for 7.6 days and regularly aggregates up to 2.76" (70mm) of snow. In Boston, during the entire year, snow falls for 29.8 days and aggregates up to 15.75" (400mm) of snow.

Ocean temperature

In Boston, the average seawater temperature in January is 41.4°F (5.2°C).
Note: Dipping into 41.4°F (5.2°C) below 50°F (10°C) needs protective wear, or you'd face cold shock and breathing issues swiftly. Meanwhile, a slight swim around 55.4°F (13°C) feels cold to the bone.

Daylight

In January, the average length of the day is 9h and 30min.
On the first day of January in Boston, Massachusetts, sunrise is at 7:13 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:56 pm EST.

Sunshine

In January, the average sunshine is 5.1h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the average person.
Note: A maximum high UV index of 2 in January translates into the following recommendations:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Forewarned is forearmed! The Sun's UV radiation can be almost doubled in intensity by snow reflection.

Updated: Jun 4, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the coldest?

January is Boston's coldest month, registering average high temperatures of 34.2°F (1.2°C) and lows of 22.6°F (-5.2°C).

How cold is January?

The high-temperature, in January, in Boston, records 34.2°F (1.2°C), while the low-temperature is 22.6°F (-5.2°C).

What is the average humidity in January?

In January, the average relative humidity is 76%.

How much does it rain in January?

In January, the rain falls for 7.9 days. Throughout January, 2.28" (58mm) of precipitation is accumulated.

How much does it snow in January?

In Boston, Massachusetts, in January, during 7.6 snowfall days, 2.76" (70mm) of snow is typically accumulated.

What is the ocean temperature in January?

In Boston, in January, the average water temperature 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 day length in January is 9h and 30min.

What time are sunrise and sunset in January?

In January, on the first day of the month, sunrise is at 7:13 am and sunset at 4:21 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:56 pm EST.

How many hours of sunshine does Boston have in January?

The average sunshine duration in January is 5.1h.

When is the lowest UV index?

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 reading in January?

In January, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year January F M A M J J A S O N D

Dec

January

Feb

Average high temperature

39.9°F 4.4°C

34.2°F 1.2°C

36.5°F 2.5°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

10.1mph 16.3km/h

10.5mph 16.9km/h

10.2mph 16.4km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

5.2

7.6

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

16.5

17.5

14.2

Average UV index

Average cloud cover

Average visibility

Average temperature in January
Boston, MA

Average high temperature in January: 34.2°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (34.2°F).

Average low temperature in January: 22.6°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

Average pressure in January
Boston, MA

Average pressure in January: 30"Hg

The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in January
Boston, MA

Average wind speed in January: 9.9mph

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).

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: 2.28"

The wettest months (with the highest rainfall) are March, April and December (2.91").
The driest month (with the least rainfall) is September (1.26").

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: 2.76"

The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in January
Boston, MA

Average snowfall days in January: 7.6 days

The months with the highest number of snowfall days are January and February (7.6 days).
The 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: 41.3°F

The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (38.1°F).

Average daylight in January /
Average sunshine in January
Boston, MA

Average daylight in January: 9h and 3min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

Average sunshine in January: 5h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

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

The months with the highest UV index are June, July and August (UV index 6).
The 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: 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).

January weather forecast
Boston, MA

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