Geology Portland lies on top of a dormant volcanic field known as the
Boring Lava Field, named after the nearby
bedroom community of
Boring. The Boring Lava Field has at least 32 cinder cones such as
Mount Tabor, and its center lies in southeast Portland.
Mount St. Helens, a highly active volcano northeast of the city in Washington state, is easily visible on clear days and is close enough to have dusted the city with volcanic ash after its
eruption on May 18, 1980. The rocks of the Portland area range in age from late
Eocene to more recent eras. Multiple shallow, active
faults traverse the Portland metropolitan area. Among them are the
Portland Hills Fault on the city's west side, and the
East Bank Fault on the east side. According to a 2017 survey, several of these faults were characterized as "probably more of a hazard" than the
Cascadia subduction zone due to their proximities to population centers, with the potential of producing
magnitude 7
earthquakes. Per a 2014 report, over 7,000 locations within the Portland area are at high risk for landslides and
soil liquefaction in the event of a major earthquake, including much of the city's west side (such as
Washington Park) and sections of
Clackamas County.
Topography Portland is east of the Pacific Ocean at the northern end of
Oregon's most populated region, the Willamette Valley. Downtown Portland straddles the banks of the Willamette River, which flows north through the city center and separates the city's east and west neighborhoods. Less than from downtown, the Willamette River flows into the Columbia River, the fourth-largest river in the United States, which divides Oregon from Washington state. Portland is approximately upriver from the Pacific Ocean on the Columbia. Though much of downtown Portland is relatively flat, the foothills of the
Tualatin Mountains, more commonly referred to locally as the "West Hills", pierce through the northwest and southwest reaches of the city.
Council Crest Park at is often quoted as the highest point in Portland; however, the highest point in Portland is on a section of NW Skyline Blvd just north of
Willamette Stone Heritage site. The highest point east of the river is
Mt. Tabor, an extinct volcanic cinder cone, which rises to . Nearby
Powell Butte and
Rocky Butte rise to and , respectively. To the west of the Tualatin Mountains lies the
Oregon Coast Range, and to the east lies the actively volcanic
Cascade Range. On clear days,
Mt. Hood and
Mt. St. Helens dominate the horizon, while
Mt. Adams and
Mt. Rainier can also be seen in the distance. According to the
United States Census Bureau, the city has an area of , of which is land and is water. Although almost all of Portland is within
Multnomah County, small portions of the city are within Clackamas and
Washington counties.
Climate Portland has a
warm-summer Mediterranean climate (
Köppen Csb), falling just short of a
hot-summer Mediterranean climate (Köppen
Csa) with cool and rainy winters, and warm and dry summers. This climate is characterized by having overcast, wet, and changing weather conditions in fall, winter, and spring, as Portland lies in the direct path of the stormy westerly flow, and warm, dry summers when the
North Pacific High reaches its northernmost point in mid-summer. Portland's
USDA Plant Hardiness Zone is 8b, with parts of the Downtown area falling into zone 9a. on February 2, 1950, The city of Portland avoids snow more frequently than its suburbs, due in part to its low elevation and the
urban heat island effect. Neighborhoods outside of the downtown core, especially in slightly higher elevations near the
West Hills and
Mount Tabor, can experience a dusting of snow while downtown receives no accumulation at all. The city has experienced a few major snow and ice storms in its past, with extreme totals having reached at the airport in 1949–50 and at downtown in 1892–93. . Pictured here is the
International Rose Test Garden. Summers in Portland are warm, dry, and sunny, though the sunny warm weather is short-lived, from mid-June to early September. June, July, August and September account for a combined of total rainfall only 11% of the of annual precipitation. The warmest month is August, with an average high temperature of . Because of its inland location from the coast, as well as the protective nature of the
Oregon Coast Range to its west, Portland summers are less susceptible to the moderating influence of the nearby Pacific Ocean. Consequently, Portland occasionally experiences
heat waves, with temperatures rising above for a few days. However, on average, temperatures reach or exceed on only 61 days per year, of which 15 days will reach and only 1.3 days will reach . In 2018 more 90-degree days were recorded than ever before. On June 28, 2021, Portland recorded its all-time record high temperature of and its warmest daily low temperature of during a
major regional heat wave. The record had been broken for three consecutive days with daytime highs of on June 26 and on June 27; the previous record of was set on July 30, 1965, and matched on August 8 & 10, 1981. A temperature of has been recorded in all five months from May through September. The warmest night of the year averages .
Cityscape Portland's cityscape derives much of its character from the many bridges that span the Willamette River downtown, several of which are historic landmarks, and Portland has been nicknamed "Bridgetown" for many decades as a result. Other bridges that span the Willamette River in the downtown area include the
Burnside Bridge, the
Ross Island Bridge (both built 1926), and the double-decker
Marquam Bridge (built 1966). Other bridges outside the downtown area include the
Sellwood Bridge (built 2016) to the south; and the
St. Johns Bridge, a
Gothic revival suspension bridge built in 1931, to the north. The
Glenn L. Jackson Memorial Bridge and the
Interstate Bridge provide access from Portland across the Columbia River into Washington state.
Addressing sections The Willamette River, which flows north through downtown, serves as the natural boundary between East and West Portland. The denser and earlier-developed west side extends into the lap of the
West Hills, while the flatter east side extends for roughly 180 blocks until it meets the suburb of
Gresham. In 1891 the cities of Portland,
Albina, and
East Portland were consolidated, creating inconsistent patterns of street names and addresses. It was not unusual for a street name to be duplicated in disparate areas. The "Great Renumbering" on September 2, 1931, standardized street naming patterns and divided Portland into five "general districts", North, Northwest, Northeast, Southeast, and Southwest (which includes
downtown Portland). House numbers were also changed from 20 per block to 100 per block and adopted a single street name on a grid. For example, the 200 block north of Burnside is either NW Davis Street or NE Davis Street throughout the entire city. With the recent addition of South Portland, Portland now has six addressing sections. All addresses and streets within the city are prefixed by N, NW, NE, S, SW or SE with the exception of
Burnside Street, which is prefixed with W or E. The Willamette River divides the city into east and west while Burnside, which traverses the entire city lengthwise, divides the north and south. Northeast, Southeast, Southwest, and Northwest Portland are respectively north or south of Burnside, and east or west of the Willamette. North Portland is a triangular peninsula bounded on the north by the Columbia River, on the east by N Williams Avenue, and on the west by the Willamette River as it bends to the northwest. South Portland was established on May 1, 2020, from a former part of Southwest Portland where the Willamette bends east of the nominal North-South meridian. House numbers on east–west streets in this area formerly had a leading zero, which was dropped as the street prefix (including north–south streets) was changed from Southwest to South. For example, the current address of 246 S California St. was formerly 0246 SW California St. and the current address of 4310 S Macadam Ave. was formerly 4310 SW Macadam Ave. The new South Portland addressing section was approved by the Portland City Council on June 6, 2018 and is bounded by
SW Naito Parkway, SW View Point Terrace and the
Tryon Creek State Natural Area to the west, SW Clay Street to the north, the Willamette River to the east, and city limits to the south. In 2018, the city's Bureau of Transportation finalized a plan to transition this part of Portland into South Portland, beginning on May 1, 2020, to reduce confusion by 9-1-1 dispatchers and delivery services. With the addition of South Portland, all six addressing sectors (N, NE, NW, S, SE and SW) are now officially known as sextants.
Neighborhoods The five previous addressing sections of Portland, which were colloquially known as quadrants despite there being five, have developed distinctive identities, with mild cultural differences and friendly rivalries between their residents, especially between those who live east of the Willamette River versus west of the river.
The Pearl District in
Northwest Portland, which was largely occupied by warehouses, light industry and railroad classification yards in the early to mid-20th century, now houses upscale
art galleries, restaurants, and retail stores, and is one of the wealthiest neighborhoods in the city. Areas further west of the Pearl District include neighborhoods known as Uptown and Nob Hill, as well as the Alphabet District and NW 23rd Ave., a major shopping street lined with clothing boutiques and other upscale retail, mixed with cafes and restaurants. Northeast Portland is home to the
Lloyd District,
Alberta Arts District, and the
Hollywood District. North Portland is largely residential and industrial. It contains
Kelley Point Park, the northernmost point of the city. It also contains the
St. Johns neighborhood, which is historically one of the most ethnically diverse and poorest neighborhoods in the city.
Old Town Chinatown is next to the Pearl District in Northwest Portland. In 1890 it was the second largest Chinese community in the United States. In 2017, the crime rate was several times above the city average. This neighborhood has been called Portland's skid row. , downtown Portland|left , downtown Portland|left Southwest Portland is largely residential.
Downtown district, made up of commercial businesses, museums,
skyscrapers, and public landmarks represents a small area within the southwest address section. Portland's South Waterfront area has been developing into a dense neighborhood of shops, condominiums, and apartments starting in the mid-2000s. Development in this area is ongoing. The area is served by the
Portland Streetcar, the
MAX Orange Line and four
TriMet bus lines. This former industrial area sat as a
brownfield prior to development in the mid-2000s. Southeast Portland is largely residential, and consists of several neighborhoods, including
Hawthorne District,
Belmont,
Brooklyn, and
Mount Tabor.
Reed College, a private liberal arts college that was founded in 1908, is located within the confines of Southeast Portland as is
Mount Tabor, a volcanic landform. South Portland includes the Lair Hill, Johns Landing and South Waterfront districts and Lewis & Clark College as well as the Riverdale area of unincorporated Multnomah County south of the Portland city limits. ==Demographics==