The Cedar Hills plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
71° on Nov. 13, 1999, the hottest reading for this week of the year since 1872. Next is 68° in 1976.
Cedar Hills’s center stands about 250 ft above sea level. Within three miles the land runs from 180 ft to 920 ft, a difference of 740 ft: hilly country. The highest named summit within 15 miles is Bald Peak, about 1,650 ft, 14 miles west-southwest.
Under the town center the state geologic map shows Lacustrine and fluvial sedimentary rocks (clay, silt, sand), from the Pleistocene, less than 2.6 million years old.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 17×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Clay, silt, sand. Age: Pleistocene, less than 2.6 million years old. About 7 mi of the line.
Sand, gravel, silt. Age: Holocene, less than 12,000 years old. About 4 mi of the line.
Basalt. Age: Miocene, 5.3 to 23 million years old. About 4 mi of the line.
Sandstone-mudstone. Age: Pliocene to Pleistocene, less than 5.3 million years old. About 3 mi of the line.
Silt, sand, gravel. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 3 smaller units along the line are not listed.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Cedar Hills reaches the Pacific Ocean by way of Beaverton Creek, Rock Creek, the Tualatin, the Willamette and the Columbia: about 180 river miles.
Lake on the way: Willamette Falls Hydroelectric Power Reservoir.
100 miles of the trip are on the Columbia.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Cedar Hills; river miles along the main stem, rounded.
Cedar Hills has a warm-summer Mediterranean climate. Summer afternoons average 81° in August; winter nights fall to about 37° in January. About 44 inches of rain fall in a normal year, with about 4 inches of snow.
On November 14 Cedar Hills normally reaches 53° and falls to 42°. The record high is 66°, in 2001; the record low 18°, in 1955. The most rain on this date, 2.18 in, fell in 1876.
Normals 1991–2020 and records since 1872 from the Portland Downtown Area threaded record (Portland Kgw-Tv, 6 miles east). NOAA, through RCC-ACIS.