Climate and monthly weather forecast
Boston, MA

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

The climate of Boston

Boston, located in Massachusetts, USA, embodies a humid continental climate where there is no dry season and summers are hot, classified as Dfa by the Köppen climate classification. This classification is prominently influenced by the city's geographical position near the North Atlantic Ocean.

Throughout the year, the climate portrays substantial shifts in temperature and precipitation. Temperatures can vary drastically from a chilly low of 22.6°F (-5.2°C) in winter to a high of 81.7°F (27.6°C) during summers. The year is distributed into months wherein the climate differs from snow-laden winters to hot, human summers with a fair bit of rain.

Highlighting some unique weather characteristics, the highest average rainfall of 2.91" (74mm) is observed in three non-consecutive months: March, April, and December. In contrast, the driest month awards go to September, measuring an average rainfall of only 1.26" (32mm).

While temperatures peak in July, snowfall is mostly constrained to the winter months, reaching a maximum of 4.72" (120mm) in February, yet drops to zero inches from June to September. However, sea temperatures originate an additional dynamic, starting on the cooler side in February at 38.1°F (3.4°C) then progressively warming until August with a peak at 67.9°F (19.9°C).

The best time to visit Boston

Between May and October would provide the most comfortable conditions for visitors to Boston. This period sees the maximum daylight hours extending to 15.2 hours in June and reasonably warm temperatures ranging from a high of 66.4°F (19.1°C) in May to 80.4°F (26.9°C) in August. Sea temperatures are also favorable, ranging from 49.2°F (9.6°C) to 67.9°F (19.9°C) during these months. The general decrease in humidity surrounding these months offers clear visibility. Alongside, rainfall is relatively low, resulting in fewer rain days.

The worst time to visit Boston

The least favourable period for visiting Boston extends from November to February when cold temperatures prevail. In these months, the maximum average temperature hardly rises above 39.9°F (4.4°C), and the minimum temperature can plunge to 22.6°F (-5.2°C). Moreover, most days experience snowfall reaching up to 4.72" (120mm) in February. Furthermore, these months offer limited daylight, decreasing to 9 hours a day in December.

Spring weather in Boston

Spring in Boston is from March to May, commencing with a blend of rain and snow. However, March experiences the most rainfall with day averages of 2.91" (74mm) over 11.6 days. With the advent of April, temperatures start to rise, reaching up to 55.2°F (12.9°C) and snowfall decreases to 0.79" (20mm). By May, the average high temperature claims 66.4°F (19.1°C), ushering in the summer.

Summer weather in Boston

Summer months in Boston from June to August depict a warm and humid atmosphere. The overall temperature experiences a high between 74.3°F (23.5°C) in June and 81.7°F (27.6°C) in July. June and July have extended daylight hours reaching as far as 15.2 hours with prominent sunshine. Meanwhile, the volume of rainfall is relatively lower than other seasons - around 2.13" (54mm) in June to 1.61" (41mm) in August.

Autumn weather in Boston

Autumn, spanning from September to November, indicates a cooling period after the hot summer. September maintains relatively warmer temperatures with highs at 72.7°F (22.6°C), gradually decreasing to 49.5°F (9.7°C) by November. Rainfall slightly increases from 1.26" (32mm) in September to 2.68" (68mm) in November. Moreover, the possibility of snowfall also resurfaces in November with 0.63" (16mm) on average.

Winter weather in Boston

Winter in Boston is from December to February and is predominantly cold and snowy. The average high temperature ranges from 39.9°F (4.4°C) in December to 34.2°F (1.2°C) in January, while the lowest averages from 29.7°F (-1.3°C) to 22.6°F (-5.2°C) in these months. December and February see the heaviest snowfall at 2.83" (72mm) and 4.72" (120mm), respectively. Daylight hours are minimal, reaching as low as 9.1 hours in December.

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). Weather in January »

Weather in February

As Boston transitions from January to February, a noticeable stride towards milder conditions does not occur. The weather conditions appear similar to January, making February another month of biting winter. February experiences different high and low temperatures ranging from 36.5°F (2.5°C) to 23.5°F (-4.7°C). Weather in February »

Weather in March

March in Boston is a transitional period, moving from winter to the refreshing spring season. Noticeable changes in the weather patterns occur as compared to February's dominant cold. The region witnesses highs and lows from 43.5°F (6.4°C) to 30.9°F (-0.6°C). Weather in March »

Weather in April

The Boston weather in April signals a definitive arrival of spring. As the month proceeds, temperatures increase steadily, and weather patterns fluctuate less than in March. In contrast to colder months, the high and low temperatures rest between 55.2°F (12.9°C) and 40.5°F (4.7°C). Weather in April »

Weather in May

Boston in May is a delight for residents, offering pleasant climatic conditions. There's a shift from April’s delicate spring towards a warmer pre-summer atmosphere. Marked weather differences show that high and low temperatures range from 66.4°F (19.1°C) to 50°F (10°C). Weather in May »

Weather in June

For Boston, June marks the onset of summer. The weather becomes warmer than that witnessed in May, and temperatures continue to climb. The city experiences a high of 74.3°F (23.5°C) and a low of 57.6°F (14.2°C). The extended daylight hours cater to evening gatherings, park outings, and barbecues. Weather in June »

Weather in July

The Boston weather in July is the epitome of summer, offering the warmest conditions of the year. Notably, Boston experiences its highest temperatures this month, with 81.7°F (27.6°C) and 64.9°F (18.3°C) being the maximum and minimum respectively. Weather in July »

Weather in August

Boston’s August weather is quite similar to July's, but with a slight decrease in temperature. Overall, a high temperature of 80.4°F (26.9°C) and a low of 64°F (17.8°C) becomes the new standard. Around this time, Boston experiences less humid conditions than those seen earlier in the summer. Weather in August »

Weather in September

As Boston steps into September, the city starts bidding farewell to summer and welcomes the fall. A shift in the weather pattern from August is noticeable, with high and low temperatures registering at 72.7°F (22.6°C) and 57.4°F (14.1°C) respectively. Weather in September »

Weather in October

October continues the beautiful descent into fall in Boston. The weather remains mild, but temperatures drop visibly if compared with September. A further change in the weather shows a high of 61.5°F (16.4°C) and a low of 48.4°F (9.1°C). Weather in October »

Weather in November

Boston in November witnesses a transition from the moderate fall climate to the cold onset of winter due to decline in temperatures. The first half of the month enjoys fall, but the frosty winter starts dominating towards the end. Weather in November »

Weather in December

For Boston, December is synonymous with winter, and the climatic conditions validate this perception. A considerable drop in temperatures from November's mildness indicates a high of 39.9°F (4.4°C) and a low of 29.7°F (-1.3°C). Weather in December »
Updated: Jun 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

Boston experiences its lowest temperatures in January, with an average peak of 34.2°F (1.2°C) and a low of 22.6°F (-5.2°C).

How much does it rain?

In Boston, during the entire year, the rain falls for 141.4 days and collects up to 27.2" (691mm) of precipitation.

When does it snow?

Months with snowfall in Boston are January through May, October through December.

How many days does it snow?

In Boston, during the entire year, snow falls for 29.8 days and aggregates up to 15.75" (400mm) of snow.

What is the month with the lowest UV index?

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

What is the most humid month in Boston?

February is the most humid month, with an average relative humidity of 77%.

What is the snowiest month?

February is the month with the most snowfall. Snow falls for 7.6 days and accumulates 4.72" (120mm) of snow.

What is the month with the coldest ocean?

With an average ocean temperature of 38.1°F (3.4°C), February is the month with the coldest seawater.

What is the month with the least sunshine?

The month with the least sunshine is February, with an average of 4.6h of sunshine.

What is the wettest month?

The months with the most rainfall are March, April and December, with an average 2.91" (74mm) of precipitation.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Boston, 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.

What is the least humid month?

With an average relative humidity of 69%, April is the least humid month in Boston.

When it does not snow?

June through September are months without snowfall.

When are the longest days?

With an average of 15h and 12min of daylight, June has the longest days of the year.

What is the month with the highest UV index?

The months with the highest UV index are June through August, with an average maximum UV index of 6.

What month is the hottest?

July is the month when Boston's temperatures reach their peak, with averages of 81.7°F (27.6°C) and lows of 64.9°F (18.3°C).

When is the ocean warmest?

The month with the warmest seawater is August, with an average ocean temperature of 68°F (20°C).

What month has the most sunshine?

August has the most sunshine of the year, with an average of 10.5h of sunshine.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 10 days and typically collects 1.26" (32mm) of precipitation.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 6min of daylight.

Average temperature
Boston, MA

Average temperature - Boston, MA

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).

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
Boston, MA

Average pressure - Boston, MA

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
Boston, MA

Average wind speed - Boston, MA

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
Boston, MA

Average humidity - Boston, MA

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

Average rainfall
Boston, MA

Average rainfall - Boston, MA

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
Boston, MA

Average rainfall days - Boston, MA

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
Boston, MA

Average snowfall - Boston, MA

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

Average snowfall days
Boston, MA

Average snowfall days - Boston, MA

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
Boston, MA

Average sea temperature - Boston, MA

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 / Average sunshine
Boston, MA

Average daylight / Average sunshine - Boston, MA

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).

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
Boston, MA

Average sunshine days - Boston, MA

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
Boston, MA

Average UV index - Boston, MA

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 visibility
Boston, MA

Average visibility - Boston, MA

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

Boston, Massachusetts, USA

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