Boston | geography

Geography

Aerial view of the Boston area from space
Boston as seen from the International Space Station (ISS)

Boston has an area of 89.63 square miles (232.1 km2)—48.4 square miles (125.4 km2) (54%) of land and 41.2 square miles (106.7 km2) (46%) of water. The city's official elevation, as measured at Logan International Airport, is 19 ft (5.8 m) above sea level.[87] The highest point in Boston is Bellevue Hill at 330 feet (100 m) above sea level, and the lowest point is at sea level.[88] Situated onshore of the Atlantic Ocean, Boston is the only state capital in the contiguous United States with an oceanic shoreline.[89]

The geographical center of Boston is in Roxbury. Due north of the center we find the South End. This is not to be confused with South Boston which lies directly east from the South End. North of South Boston is East Boston and southwest of East Boston is the North End.

— Author, Unknown – A common local colloquialism

Boston is surrounded by the "Greater Boston" region and is contiguously bordered by the cities and towns of Winthrop, Revere, Chelsea, Everett, Somerville, Cambridge, Watertown, Newton, Brookline, Needham, Dedham, Canton, Milton, and Quincy. The Charles River separates Boston’s Allston-Brighton, Fenway-Kenmore and Back Bay neighborhoods from Watertown and the majority of Cambridge, and the mass of Boston from its own Charlestown neighborhood. To the east lie Boston Harbor and the Boston Harbor Islands National Recreation Area (which includes part of the city's territory, specifically Calf Island, Gallops Island, Great Brewster Island, Green Island, Little Brewster Island, Little Calf Island, Long Island, Lovells Island, Middle Brewster Island, Nixes Mate, Outer Brewster Island, Rainsford Island, Shag Rocks, Spectacle Island, The Graves, and Thompson Island). The Neponset River forms the boundary between Boston's southern neighborhoods and the city of Quincy and the town of Milton. The Mystic River separates Charlestown from Chelsea and Everett, and Chelsea Creek and Boston Harbor separate East Boston from Downtown, the North End, and the Seaport.[90]

Cityscapes

Sailboats on the Charles River overlook the Boston skyline, as seen from Cambridge.
Sunset view of the Boston skyline and Charles River

 

Neighborhoods

200 Clarendon Street is the tallest building in Boston, with a roof height of 790 feet (240 m).

Boston is sometimes called a "city of neighborhoods" because of the profusion of diverse subsections; the city government's Office of Neighborhood Services has officially designated 23 neighborhoods.[91] More than two-thirds of inner Boston's modern land area did not exist when the city was founded. Instead, it was created via the gradual filling in of the surrounding tidal areas over the centuries,[65] with earth from leveling or lowering Boston's three original hills (the "Trimountain", after which Tremont Street is named) and with gravel brought by train from Needham to fill the Back Bay.[16]

Downtown and its immediate surroundings consist largely of low-rise masonry buildings (often Federal style and Greek Revival) interspersed with modern highrises, in the Financial District, Government Center, and South Boston.[92] Back Bay includes many prominent landmarks, such as the Boston Public Library, Christian Science Center, Copley Square, Newbury Street, and New England's two tallest buildings: the John Hancock Tower and the Prudential Center.[93] Near the John Hancock Tower is the old John Hancock Building with its prominent illuminated beacon, the color of which forecasts the weather.[94] Smaller commercial areas are interspersed among areas of single-family homes and wooden/brick multi-family row houses. The South End Historic District is the largest surviving contiguous Victorian-era neighborhood in the US.[95] The geography of downtown and South Boston was particularly affected by the Central Artery/Tunnel Project (known unofficially as the "Big Dig") which removed the unsightly elevated Central Artery and incorporated new green spaces and open areas.[96]

Climate

Autumn foliage with a city skyline in the distant background
Boston's skyline in the background, with fall foliage in the foreground
Boston
Climate chart (explanation)
J
F
M
A
M
J
J
A
S
O
N
D
 
 
3.4
 
 
36
22
 
 
3.3
 
 
39
25
 
 
4.3
 
 
45
31
 
 
3.7
 
 
56
41
 
 
3.5
 
 
66
50
 
 
3.7
 
 
76
60
 
 
3.4
 
 
81
65
 
 
3.4
 
 
80
65
 
 
3.4
 
 
72
57
 
 
3.9
 
 
61
47
 
 
4
 
 
52
38
 
 
3.8
 
 
41
28
Average max. and min. temperatures in °F
Precipitation totals in inches

Under the Köppen climate classification, depending on the isotherm used, Boston has either a humid subtropical climate (Köppen Cfa) under the −3 °C (26.6 °F) isotherm or a humid continental climate under the 0 °C isotherm (Köppen Dfa).[97] The city is best described as being in a transitional zone between the two climates. Summers are typically warm and humid, while winters are cold and stormy, with occasional periods of heavy snow. Spring and fall are usually cool to mild, with varying conditions dependent on wind direction and jet stream positioning. Prevailing wind patterns that blow offshore minimize the influence of the Atlantic Ocean. However, in winter areas near the immediate coast will often see more rain than snow as warm air is drawn off the Atlantic at times.[98] The city lies at the transition between USDA plant hardiness zones 6b (most of the city) and 7a (Downtown, South Boston, and East Boston neighborhoods).[99]

The hottest month is July, with a mean temperature of 73.4 °F (23.0 °C). The coldest month is January, with a mean of 29.0 °F (−1.7 °C). Periods exceeding 90 °F (32 °C) in summer and below freezing in winter are not uncommon but rarely extended, with about 13 and 25 days per year seeing each, respectively.[100] The most recent sub-0 °F (−18 °C) reading occurred on January 7, 2018, when the temperature dipped down to −2 °F (−19 °C).[100] In addition, several decades may pass between 100 °F (38 °C) readings, with the most recent such occurrence on July 22, 2011, when the temperature reached 103 °F (39 °C).[100] The city's average window for freezing temperatures is November 9 through April 5.[100][c] Official temperature records have ranged from −18 °F (−28 °C) on February 9, 1934, up to 104 °F (40 °C) on July 4, 1911. The record cold daily maximum is 2 °F (−17 °C) on December 30, 1917 while, conversely, the record warm daily minimum is 83 °F (28 °C) on August 2, 1975 and July 21, 2019.[101][100]

A graph of cumulative winter snowfall at Logan International Airport from 1938–2015. The four winters with the greatest amount of snowfall are highlighted. The snowfall data, which was collected by NOAA, is from the weather station at the airport.

Boston's coastal location on the North Atlantic moderates its temperature but makes the city very prone to Nor'easter weather systems that can produce much snow and rain.[98] The city averages 43.8 inches (1,110 mm) of precipitation a year, with 43.8 inches (111 cm) of snowfall per season.[100] Snowfall increases dramatically as one goes inland away from the city (especially north and west of the city)—away from the moderating influence of the ocean.[102] Most snowfall occurs from mid-November through early April, and snow is rare in May and October.[103][104] There is also high year-to-year variability in snowfall; for instance, the winter of 2011–12 saw only 9.3 in (23.6 cm) of accumulating snow, but the previous winter, the corresponding figure was 81.0 in (2.06 m).[100][d]

Fog is fairly common, particularly in spring and early summer. Due to its location along the North Atlantic, the city often receives sea breezes, especially in the late spring, when water temperatures are still quite cold and temperatures at the coast can be more than 20 °F (11 °C) colder than a few miles inland, sometimes dropping by that amount near midday.[105][106] Thunderstorms occur from May to September, that are occasionally severe with large hail, damaging winds and heavy downpours.[98] Although downtown Boston has never been struck by a violent tornado, the city itself has experienced many tornado warnings. Damaging storms are more common to areas north, west, and northwest of the city.[107] Boston has a relatively sunny climate for a coastal city at its latitude, averaging over 2,600 hours of sunshine per annum.

Climate data for Boston
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Average sea temperature °F (°C) 41.3
(5.2)
38.1
(3.4)
38.4
(3.5)
43.1
(6.2)
49.2
(9.5)
58.4
(14.7)
65.7
(18.7)
67.9
(20.0)
64.8
(18.2)
59.4
(15.3)
52.3
(11.3)
46.6
(8.2)
52.1
(11.2)
Source: Weather Atlas [111]