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Average weather, temperature, rainfall, sunshine hours
In Boston, the capital of the State of Massachusetts, the climate is
continental, with very cold, snowy winters and warm to hot summers, during which there are quite frequent thunderstorms. The city is located at 42 degrees north latitude, on the coast of the Atlantic Ocean (Gulf of Maine), where a cold current flows.
Also, in this area, different air masses collide: those coming from Canada and those coming from the Gulf of Mexico. The result is an
unstable climate, with waves of bad weather alternating with clear and sunny days.
At the Logan International Airport, located right on the coast, the daily
average temperature ranges from -1 °C (30 °F) in January to 23.5 °C (74 °F) in July.
That of the airport is the mildest area of the city; in inland neighborhoods and suburbs, night temperatures are lower. For example, in Bedford, located 25 km (15 mi) to the north-west, the daily average temperature ranges from -2.5 °C (27.5 °F) in January to 23 °C (73.5 °F) in July.
Precipitation in Boston is quite abundant, since it amounts to 1,100 millimeters (43 inches) per year, and it's well distributed over the seasons. In winter, it occurs mainly in the form of snow, while in summer, in addition to some weather disturbances that can bring some rainy days, thunderstorms in the afternoon or in the evening are quite frequent.
Winter, from December to mid-March, is very cold: the average temperature is just below freezing (0 °C or 32 °F), but cold spells, with temperatures dropping to -15 °C (5 °F) or even below, are not uncommon. The cold record is -24.5 °C (-12 °F), recorded in January 1957. From 2001 to 2020, the record was -23 °C (-9.5 °F), set in February 2016.
The
freezing wind, called blizzard, can heighten the feeling of cold.
Snowfalls are frequent, and sometimes can be abundant, resulting in real snowstorms: for example, during the storm of the 17/18th of February 2003, 70 centimeters (27 inches) of snow fell, while on the 1st of April 1997, 64.5 cm (25.4 in) of snow fell, and on the 26/27th of January 2015, 62.5 cm (24.6 in) of snow fell. Snow covers the ground for weeks. An average of 125 cm (49 in) of snow falls per year.
On other occasions, the south wind can bring some mild days, during which highs can reach 12/15 °C (54/59 °F), but this occurs less frequently than in New York.
In
spring, from mid-March to mid-June, the weather continues to be
unstable: the first warm days alternate with the return of cold weather. In March, which is often still a wintery month, it snows on a frequent basis, and sometimes, this can happen even in April, especially at the beginning of the month. But already in April, the temperature can sometimes reach or even exceed 25 °C (77 °F).
By May, the average temperature is pleasant, although there are still cool days, or even cold and rainy, while the first heat waves can raise the temperature above 30 °C (86 °F). On sunny days, also the first
afternoon thunderstorms can erupt. In late spring and early summer, fog may form, maybe on rainy days. When the weather is fine, in the afternoon, a cool and moderate breeze rises from the sea.
The Boston Marathon is held on the third Monday of April, ie around the middle of the month, when the average temperatures are very cool or even a little cold: in April, the average is 5 °C (41 °F) as minimum temperature and 13.5 °C (56.5 °F) as maximum temperature.
Summer, from mid-June to August, is
warm to hot and humid. Different situations can occur in this season as well: there are cool days, maybe with some rain, and with highs around 23/24 °C (73/75 °F), but also hot and quite muggy days, with highs around 28 °C (82 °F), with sunshine and the sea breeze.
Sometimes, even
heat waves can occur, with daytime temperatures reaching or exceeding 35 °C (95 °F), and night temperatures remaining around 23/25 °C (73/77 °F). The record heat is 39.5 °C (103 °F), recorded in July 2011.
The amount of sunshine during the summer is good, however, in addition to some weather fronts, there is a fair amount of
afternoon thunderstorms, sometimes intense and accompanied by hail.
Autumn, from September to November, is the mildest and less unstable season of the year, at least in the first part. In early September, the weather can still be characterized by heat and humidity, with sunshine and some afternoon thunderstorms, then it quickly becomes mild until mid-October, while in the second half of October, it can start to be a bit cold. November is already a cold month, and the first snowfalls can occur. Rainfall occurs quite often also in this season.
The amount of
sunshine in Boston is good in summer, but it is not scarce even in winter because, as mentioned, some sunny days can always occur. On average, there are 2,635 hours of sunshine per year.
The
sea in Boston, very cold in winter, remains very cool even in summer, in fact, it reaches 20 °C (68 °F) in August. As mentioned, a cold current flows in the sea, in fact, the Gulf of Maine in winter is affected by an offshoot of the Labrador current.
Best Time
In order to avoid both the winter cold and the summer heat, the
best times to visit Boston are spring and autumn, and in particular from mid-May to mid-June, and from early September to early October. June is often a good month too, but we can not exclude some hot days. In early September, the weather is often hot and humid, although not as hot as in midsummer. In May, it can sometimes get cold, and the weather can be unstable, especially at the beginning of the month, while generally, the second half of the month is mild.
In autumn (usually around late October), you can admire the beautiful colors of the trees losing their leaves (the phenomenon called
fall foliage).
Bedford - Climate data
In Boston, the
average temperature of the coldest month (January) is of
-1.1 °C, that of the warmest month (July) is of
23.4 °C. Here are the average temperatures.
Boston - Average temperatures (1991-2020) |
| Month | Min | Max | Mean |
|---|
| January | -4.9 | 2.7 | -1.1 |
|---|
| February | -4.1 | 3.9 | -0.1 |
|---|
| March | -0.5 | 7.5 | 3.5 |
|---|
| April | 4.9 | 13.6 | 9.2 |
|---|
| May | 10.2 | 19.2 | 14.7 |
|---|
| June | 15.4 | 24.6 | 20 |
|---|
| July | 18.9 | 27.8 | 23.4 |
|---|
| August | 18.4 | 26.9 | 22.6 |
|---|
| September | 14.6 | 22.8 | 18.7 |
|---|
| October | 8.6 | 16.7 | 12.6 |
|---|
| November | 3.3 | 10.9 | 7.1 |
|---|
| December | -1.6 | 5.7 | 2 |
|---|
| Year | 7 | 15.3 | 11.1 |
|---|
amounts to
1105 millimeters per year: it is therefore quite abundant. It ranges from
80 millimeters in the driest months (February, August) to
110 millimeters in the wettest one (December). Here is the average precipitation.
Boston - Average precipitation| Month | Days |
|---|
| January | 85 | 12 |
|---|
| February | 80 | 11 |
|---|
| March | 105 | 12 |
|---|
| April | 90 | 12 |
|---|
| May | 85 | 12 |
|---|
| June | 100 | 11 |
|---|
| July | 85 | 9 |
|---|
| August | 80 | 9 |
|---|
| September | 90 | 9 |
|---|
| October | 100 | 10 |
|---|
| November | 95 | 10 |
|---|
| December | 110 | 12 |
|---|
| Year | 1105 | 128 |
|---|
The
sea temperature ranges from
3.5 °C in March to
20 °C in August. Here are the average sea temperatures.
Boston - Sea temperature| Month |
|---|
| January | 5.5 |
|---|
| February | 4 |
|---|
| March | 3.5 |
|---|
| April | 5 |
|---|
| May | 9 |
|---|
| June | 14 |
|---|
| July | 18.5 |
|---|
| August | 20 |
|---|
| September | 18 |
|---|
| October | 14 |
|---|
| November | 10.5"> |
|---|
| December | 8 |
|---|
| Year | 10.9 |
|---|
There are on average around 2635
sunshine hours per year. Here are the average hours of sunshine per day.
Boston - Sunshine hours| Month | Average | Total |
|---|
| January | 5.5 | 165 |
|---|
| February | 6 | 170 |
|---|
| March | 7 | 215 |
|---|
| April | 7.5 | 225 |
|---|
| May | 8.5 | 265 |
|---|
| June | 9.5 | 285 |
|---|
| July | 9.5 | 300 |
|---|
| August | 9 | 275 |
|---|
| September | 8 | 235 |
|---|
| October | 6.5 | 205 |
|---|
| November | 5 | 145 |
|---|
| December | 4.5 | 140 |
|---|
| Year | 7.2 | 2635 |
|---|
Boston - Weather by month
Based on the period 1991-2020
January, the coldest month of the year, is generally a very cold month. The average temperature is of
-1.1 °C, with a minimum of
-4.9 °C and a maximum of
2.7 °C.
On the coldest nights of the month, the temperature usually drops to around
-15 °C.
On the warmest days of the month, the temperature usually reaches around
14.5 °C.
Precipitation amounts to
85 mm, distributed over 12 days.
The day lasts on average 9 hours and 30 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 62%.
The average wind speed is of
19 kph.
The average sea temperature is of
5.4 °C. Therefore, the sea is very cold for swimming.
February is generally a very cold month. The average temperature is of
-0.1 °C, with a minimum of
-4.1 °C and a maximum of
3.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-13 °C.
On the warmest days of the month, the temperature usually reaches around
14.5 °C.
Precipitation amounts to
80 mm, distributed over 11 days.
The day lasts on average 10 hours and 35 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 62%.
The average wind speed is of
19 kph.
The average sea temperature is of
3.8 °C. Therefore, the sea is very cold for swimming.
March is generally a cold month. The average temperature is of
3.5 °C, with a minimum of
-0.5 °C and a maximum of
7.5 °C.
On the coldest nights of the month, the temperature usually drops to around
-9 °C.
On the warmest days of the month, the temperature usually reaches around
19.5 °C.
Precipitation amounts to
105 mm, distributed over 12 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 63%.
The average wind speed is of
19 kph.
The average sea temperature is of
3.5 °C. Therefore, the sea is very cold for swimming.
April is generally a mild month. The average temperature is of
9.2 °C, with a minimum of
4.9 °C and a maximum of
13.6 °C.
On the coldest nights of the month, the temperature usually drops to around
-0.5 °C.
On the warmest days of the month, the temperature usually reaches around
26.5 °C.
Precipitation amounts to
90 mm, distributed over 12 days.
The day lasts on average 13 hours and 25 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 56% of the time.
The average humidity is 63%.
The average wind speed is of
19 kph.
The average sea temperature is of
5.2 °C. Therefore, the sea is very cold for swimming.
May is generally a very mild month. The average temperature is of
14.7 °C, with a minimum of
10.2 °C and a maximum of
19.2 °C.
On the coldest nights of the month, the temperature usually drops to around
5 °C.
On the warmest days of the month, the temperature usually reaches around
31 °C.
Precipitation amounts to
85 mm, distributed over 12 days.
The day lasts on average 14 hours and 35 minutes. So the days are long.
There are on average 8.5 hours of sunshine per day. So, the sun shines 59% of the time.
The average humidity is 67%.
The average wind speed is of
17 kph.
The average sea temperature is of
9.1 °C. Therefore, the sea is very cold for swimming.
June is generally a warm month. The average temperature is of
20 °C, with a minimum of
15.4 °C and a maximum of
24.6 °C.
On the coldest nights of the month, the temperature usually drops to around
10 °C.
On the warmest days of the month, the temperature usually reaches around
33.5 °C.
Precipitation amounts to
100 mm, distributed over 11 days.
The day lasts on average 15 hours and 10 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 9.5 hours of sunshine per day. So, the sun shines 63% of the time.
The average humidity is 68%.
The average wind speed is of
16 kph.
The average sea temperature is of
14 °C. Therefore, the sea is very cold for swimming.
July, the warmest month of the year, is generally a warm to hot month. The average temperature is of
23.4 °C, with a minimum of
18.9 °C and a maximum of
27.8 °C.
On the coldest nights of the month, the temperature usually drops to around
15 °C.
On the warmest days of the month, the temperature usually reaches around
35 °C.
Precipitation amounts to
85 mm, distributed over 9 days.
The day lasts on average 14 hours and 55 minutes. So the days are long.
There are on average 9.5 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 68%.
The average wind speed is of
15 kph.
The average sea temperature is of
18.6 °C. Therefore, the sea is very cool for swimming.
August is generally a warm to hot, muggy month. The average temperature is of
22.6 °C, with a minimum of
18.4 °C and a maximum of
26.9 °C.
On the coldest nights of the month, the temperature usually drops to around
14.5 °C.
On the warmest days of the month, the temperature usually reaches around
34.5 °C.
Precipitation amounts to
80 mm, distributed over 9 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 9 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
14 kph.
The average sea temperature is of
19.8 °C. Therefore, the sea is very cool for swimming.
September is generally a warm month. The average temperature is of
18.7 °C, with a minimum of
14.6 °C and a maximum of
22.8 °C.
On the coldest nights of the month, the temperature usually drops to around
8 °C.
On the warmest days of the month, the temperature usually reaches around
31.5 °C.
Precipitation amounts to
90 mm, distributed over 9 days.
The day lasts on average 12 hours and 25 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 64% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is of
15 kph.
The average sea temperature is of
17.8 °C. Therefore, the sea is cold for swimming.
October is generally a mild month. The average temperature is of
12.6 °C, with a minimum of
8.6 °C and a maximum of
16.7 °C.
On the coldest nights of the month, the temperature usually drops to around
1.5 °C.
On the warmest days of the month, the temperature usually reaches around
26.5 °C.
Precipitation amounts to
100 mm, distributed over 10 days.
The day lasts on average 11 hours and 0 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 60% of the time.
The average humidity is 68%.
The average wind speed is of
16 kph.
The average sea temperature is of
14.2 °C. Therefore, the sea is very cold for swimming.
November is generally a quite mild month. The average temperature is of
7.1 °C, with a minimum of
3.3 °C and a maximum of
10.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-4 °C.
On the warmest days of the month, the temperature usually reaches around
21 °C.
Precipitation amounts to
95 mm, distributed over 10 days.
The day lasts on average 9 hours and 50 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 68%.
The average wind speed is of
18 kph.
The average sea temperature is of
10.7 °C. Therefore, the sea is very cold for swimming.
December is generally a cold month. The average temperature is of
2 °C, with a minimum of
-1.6 °C and a maximum of
5.7 °C.
On the coldest nights of the month, the temperature usually drops to around
-10.5 °C.
On the warmest days of the month, the temperature usually reaches around
16 °C.
Precipitation amounts to
110 mm, distributed over 12 days.
The day lasts on average 9 hours and 5 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 4.5 hours of sunshine per day. So, the sun shines 51% of the time.
The average humidity is 65%.
The average wind speed is of
18 kph.
The average sea temperature is of
7.9 °C. Therefore, the sea is very cold for swimming.