The Chilmark 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. 11, 1999, the hottest reading for this week of the year since 1946. Next is 71° in 2022.
Chilmark’s center stands about 13 ft above sea level. Within three miles the land runs from 0 ft to 160 ft, a difference of 160 ft: gently rolling country. Open water lies within three miles. The highest named summit within 15 miles is Peaked Hill, about 320 ft, 4 miles north-northeast.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Fine-detrital, coarse-detrital. Age: Cretaceous to Late Cretaceous, 72 to 145 million years old. About 10 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.
Rain that falls on Chilmark runs straight into the Atlantic Ocean.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Chilmark; river miles along the main stem, rounded.
Chilmark has a humid subtropical climate. Summer afternoons average 80° in July; winter nights fall to about 26° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 48 inches of water.
On November 14 Chilmark normally reaches 55° and falls to 40°. The record high is 63°, in 2012; the record low 20°, in 2019. The most rain on this date, 1.70 in, fell in 1975.
Normals 1991–2020 and records since 1946 at Edgartown, 15 miles east-northeast. NOAA, through RCC-ACIS.