The Beacon Hill 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.
3.49 inches of rain fell in two days, the most for this week of the year since records began in 1925. The next wettest, 3.36 inches, fell in 2021.
Beacon Hill’s center stands about 220 ft above sea level. Within three miles the land runs from 0 ft to 1,010 ft, a difference of 1,010 ft: steep hill country. The highest named summit within 15 miles is Baird Mountain, about 2,670 ft, 15 miles east.
Under the town center the state geologic map shows Pliocene nonmarine rocks (conglomerate), from the Pliocene, 2.6 to 5.3 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 10×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Basalt, basaltic-andesite. Age: Late Eocene to Oligocene, 23 to 38 million years old. About 8 mi of the line.
Basalt. Age: Late Oligocene to Early Pliocene, 3.6 to 28 million years old. About 6 mi of the line.
Sandstone. Age: Early Eocene to Middle Eocene, 38 to 56 million years old. About 6 mi of the line.
Conglomerate. Age: Pliocene, 2.6 to 5.3 million years old. About 2 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
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 Beacon Hill reaches the Pacific Ocean by way of the Cowlitz and the Columbia: about 75 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Beacon Hill; river miles along the main stem, rounded.
Beacon Hill has a warm-summer Mediterranean climate. Summer afternoons average 80° in August; winter nights fall to about 35° in January. About 48 inches of rain fall in a normal year.
On November 14 Beacon Hill normally reaches 53° and falls to 39°. The record high is 68°, in 1999; the record low 12°, in 1955. The most rain on this date, 1.65 in, fell in 2001.
Normals 1991–2020 and records since 1925 at Longview, 4 miles southwest, 210 ft lower. NOAA, through RCC-ACIS.