Topography
Seattle is located between Puget Sound, an inlet of the Pacific Ocean, and Lake Washington. West beyond the Sound are the Olympic Mountains; east beyond Lake Washington and the Eastside suburbs are Lake Sammamish, the Issaquah Alps, and the Cascade Range. The rivers, forests, lakes, and fields were once rich enough to support one of the world's few sedentary hunter-gatherer societies. Opportunities for sailing, skiing, bicycling, camping, and hiking are nearby and accessible almost all the year.
The city itself, somewhat like San Francisco, is hilly, though not uniformly so. Like Rome, the city is said to lie on seven hills; Capitol Hill, First Hill, West Seattle, Beacon Hill, & Queen Anne being a few. The hilliest areas are near an isthmus in the city center, away from the chief harbor, an inlet of Puget Sound called Elliott Bay. The geography of Downtown has been reshaped by regrading projects, a seawall, and the construction of an artificial island, Harbor Island, at the mouth of the city's industrial Duwamish Waterway.
The man-made Lake Washington Ship Canal incorporating four natural bodies of water: Lake Union, Salmon Bay, Portage Bay, and Union Bay. The canal connects Puget Sound to Lake Washington.
An active geological fault, the Seattle Fault, runs under the city. Although neither the Seattle Fault nor the Cascadia Subduction Zone have caused an earthquake since the city’s founding, the city has been hit by four major earthquakes: December 14, 1872 (magnitude 7.3); April 13, 1949 (7.1); April 29, 1965 (6.5); and the Nisqually Earthquake of February 28, 2001 (6.8). The Cascadia subduction zone poses the even greater threat of an earthquake of magnitude 9.0 or greater, capable of seriously damaging the city and collapsing many buildings, particularly Downtown and in the Industrial District, which is built on fill.
According to the United States Census Bureau, the city has a total area of 369.2 km² (142.5 mi²),GR1 217.2 km² (83.9 mi²) of which is land and 152.0 km² (58.7 mi²) water. The total area is 41.16% water.
See also: Seattle neighborhoods, List of Seattle parks, Bodies of water of Seattle, Seven hills of Seattle
Seattle has grown through a series of annexations of smaller neighboring communities:
In 2006, a proposal was floated to annex currently unincorporated communities on what is presently Seattle's southern boundary.
Climate
Seattle has a mild climate that is usually classified as Marine west coast (Cfb). However, due to its wet-winter dry-summer pattern, it shows some characteristics of a Mediterranean climate (Csb), and is sometimes classified this way. Temperature extremes are moderated by adjacent Puget Sound and Lake Washington as well as the more distant Pacific Ocean. The region is partially protected from Pacific storms by the Olympic Mountains and from Arctic air by the Cascade Range. Despite being on the margin of the rain shadow of the Olympic Mountains, the city of Seattle has a reputation for frequent rain. In reality, the so-called "rainy city" receives an unremarkable 37.1 inches (94.2 cm) of precipitation a year, which is much less precipitation than New York City, Atlanta, and Houston and most cities of the Eastern Seaboard of the United States. Seattle's worldwide reputation for rain derives from the fact that it is cloudy (not rainy) an average of 226 days per year (vs. 132 in New York City). Most of the precipitation falls as drizzle or light rain, with downpours happening only occasionally. The spring, late fall, and winter are filled with days when it does not rain but looks as if it may because of cloudy, overcast skies. As for temperature, winters are cool and wet with average lows around 35–40 °F (2–4 °C) on winter nights. Colder weather can occur at times, but seldom lasts more than a few days. Summers are dry and warm, with average daytime highs around 75–80 °F (24–27 °C). Hotter weather can also occur, but usually only during a few days of the summer. Seattle's hottest official recorded temperature was 100 °F (38 °C) on July 20, 1994; the coldest recorded temperature was 0 °F (-18 °C) on January 31, 1950.
To the west 80 miles (130 km), the Hoh Rain Forest, in Olympic National Park on the western flank of the Olympic Mountains, receives an annual average rainfall of 142 inches (361 cm), and the state capital, Olympia, south of the rain shadow, receives an annual average rainfall of 52 inches (132 cm). Snowfall is infrequent, especially at lower altitudes and near the coast, and is usually light and fleeting, lasting only a few days. Average annual snowfall, as measured at Sea-Tac Airport, is 13 inches (33 cm). On January 13, 1880, Seattle's record for snowfall was set at 49 inches (124 cm). Sunnier and drier "California weather" typically dominates from mid-July to mid-September. An average of 0.8 inches (2.0 cm) of rain falls in July and an average of 1.0 inches (2.5 cm) falls in August. Although the summer climate in the Seattle area is considerably drier and less humid than areas with humid continental climates, a slight dampness can be occasionally felt, usually when temperatures reach above 80 °F. This dampness is typically more noticeable during the evening when the temperatures have dropped. Because of this, Seattle does experience occasional summer thunderstorms.
The Puget Sound Convergence Zone is an important feature of Seattle's weather. In the convergence zone, air arriving in the area from the north meets air flowing in from the south. Both streams of air originate over the Pacific Ocean; airflow is split by the Olympic Mountains to Seattle's west, then reunited by the Cascade Mountains to the east. When the air currents meet, they are forced upward, resulting in convection.
Thunderstorms caused by this activity can occur north and south of town, but Seattle itself rarely receives worse weather than occasional thunder and ice pellet showers. Thunderstorms in the Cascades sometimes produce frequent lightning, which makes for a brilliant light show for those in town.
An exception to Seattle's dampness often occurs in El Niño years, when the marine weather systems track as far south as California and little precipitation falls in the Puget Sound area. Since the region's water comes from mountain snowpacks during the drier summer months, El Niño winters not only produce substandard skiing but can result in water rationing and a shortage of hydro-electric power the following summer.
Seattle is located between Puget Sound, an inlet of the Pacific Ocean, and Lake Washington. West beyond the Sound are the Olympic Mountains; east beyond Lake Washington and the Eastside suburbs are Lake Sammamish, the Issaquah Alps, and the Cascade Range. The rivers, forests, lakes, and fields were once rich enough to support one of the world's few sedentary hunter-gatherer societies. Opportunities for sailing, skiing, bicycling, camping, and hiking are nearby and accessible almost all the year.
The city itself, somewhat like San Francisco, is hilly, though not uniformly so. Like Rome, the city is said to lie on seven hills; Capitol Hill, First Hill, West Seattle, Beacon Hill, & Queen Anne being a few. The hilliest areas are near an isthmus in the city center, away from the chief harbor, an inlet of Puget Sound called Elliott Bay. The geography of Downtown has been reshaped by regrading projects, a seawall, and the construction of an artificial island, Harbor Island, at the mouth of the city's industrial Duwamish Waterway.
The man-made Lake Washington Ship Canal incorporating four natural bodies of water: Lake Union, Salmon Bay, Portage Bay, and Union Bay. The canal connects Puget Sound to Lake Washington.
An active geological fault, the Seattle Fault, runs under the city. Although neither the Seattle Fault nor the Cascadia Subduction Zone have caused an earthquake since the city’s founding, the city has been hit by four major earthquakes: December 14, 1872 (magnitude 7.3); April 13, 1949 (7.1); April 29, 1965 (6.5); and the Nisqually Earthquake of February 28, 2001 (6.8). The Cascadia subduction zone poses the even greater threat of an earthquake of magnitude 9.0 or greater, capable of seriously damaging the city and collapsing many buildings, particularly Downtown and in the Industrial District, which is built on fill.
According to the United States Census Bureau, the city has a total area of 369.2 km² (142.5 mi²),GR1 217.2 km² (83.9 mi²) of which is land and 152.0 km² (58.7 mi²) water. The total area is 41.16% water.
See also: Seattle neighborhoods, List of Seattle parks, Bodies of water of Seattle, Seven hills of Seattle
Seattle has grown through a series of annexations of smaller neighboring communities:
- Magnolia, Wallingford, Green Lake, and University District: May 3, 1891 * South Seattle: October 20, 1905
- Southeast Seattle, Ravenna, South Park, Columbia, Ballard, and West Seattle: from January 7, 1907 to September 12, 1907
- Georgetown: March 29, 1910
- Northernmost suburbs: January 4, 1954
In 2006, a proposal was floated to annex currently unincorporated communities on what is presently Seattle's southern boundary.
Climate
Seattle has a mild climate that is usually classified as Marine west coast (Cfb). However, due to its wet-winter dry-summer pattern, it shows some characteristics of a Mediterranean climate (Csb), and is sometimes classified this way. Temperature extremes are moderated by adjacent Puget Sound and Lake Washington as well as the more distant Pacific Ocean. The region is partially protected from Pacific storms by the Olympic Mountains and from Arctic air by the Cascade Range. Despite being on the margin of the rain shadow of the Olympic Mountains, the city of Seattle has a reputation for frequent rain. In reality, the so-called "rainy city" receives an unremarkable 37.1 inches (94.2 cm) of precipitation a year, which is much less precipitation than New York City, Atlanta, and Houston and most cities of the Eastern Seaboard of the United States. Seattle's worldwide reputation for rain derives from the fact that it is cloudy (not rainy) an average of 226 days per year (vs. 132 in New York City). Most of the precipitation falls as drizzle or light rain, with downpours happening only occasionally. The spring, late fall, and winter are filled with days when it does not rain but looks as if it may because of cloudy, overcast skies. As for temperature, winters are cool and wet with average lows around 35–40 °F (2–4 °C) on winter nights. Colder weather can occur at times, but seldom lasts more than a few days. Summers are dry and warm, with average daytime highs around 75–80 °F (24–27 °C). Hotter weather can also occur, but usually only during a few days of the summer. Seattle's hottest official recorded temperature was 100 °F (38 °C) on July 20, 1994; the coldest recorded temperature was 0 °F (-18 °C) on January 31, 1950.
To the west 80 miles (130 km), the Hoh Rain Forest, in Olympic National Park on the western flank of the Olympic Mountains, receives an annual average rainfall of 142 inches (361 cm), and the state capital, Olympia, south of the rain shadow, receives an annual average rainfall of 52 inches (132 cm). Snowfall is infrequent, especially at lower altitudes and near the coast, and is usually light and fleeting, lasting only a few days. Average annual snowfall, as measured at Sea-Tac Airport, is 13 inches (33 cm). On January 13, 1880, Seattle's record for snowfall was set at 49 inches (124 cm). Sunnier and drier "California weather" typically dominates from mid-July to mid-September. An average of 0.8 inches (2.0 cm) of rain falls in July and an average of 1.0 inches (2.5 cm) falls in August. Although the summer climate in the Seattle area is considerably drier and less humid than areas with humid continental climates, a slight dampness can be occasionally felt, usually when temperatures reach above 80 °F. This dampness is typically more noticeable during the evening when the temperatures have dropped. Because of this, Seattle does experience occasional summer thunderstorms.
The Puget Sound Convergence Zone is an important feature of Seattle's weather. In the convergence zone, air arriving in the area from the north meets air flowing in from the south. Both streams of air originate over the Pacific Ocean; airflow is split by the Olympic Mountains to Seattle's west, then reunited by the Cascade Mountains to the east. When the air currents meet, they are forced upward, resulting in convection.
Thunderstorms caused by this activity can occur north and south of town, but Seattle itself rarely receives worse weather than occasional thunder and ice pellet showers. Thunderstorms in the Cascades sometimes produce frequent lightning, which makes for a brilliant light show for those in town.
An exception to Seattle's dampness often occurs in El Niño years, when the marine weather systems track as far south as California and little precipitation falls in the Puget Sound area. Since the region's water comes from mountain snowpacks during the drier summer months, El Niño winters not only produce substandard skiing but can result in water rationing and a shortage of hydro-electric power the following summer.