The Head of the Harbor 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.
Partly cloudy
Mostly sunny; warmer
Partly cloudy
Sunny
Mostly sunny
Mostly sunny
Mostly sunny
77° on Nov. 15, 1993, the hottest reading for this week of the year since 1963. Next is 72° in 2022.
Head of the Harbor’s center stands about 190 ft above sea level. Within three miles the land runs from 0 ft to 230 ft, a difference of 230 ft: rolling country. Open water lies within three miles. The highest named summit within 15 miles is High Hill, about 420 ft, 15 miles west-southwest.
Under the town center the state geologic map shows Monmouth Group, Matawan Group and Magothy Formation (clay, sand, gravel), from the Late Cretaceous, 66 to 100 million years old.
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.
Clay, sand, gravel. Age: Late Cretaceous, 66 to 100 million years old. About 14 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 Head of the Harbor runs straight into Long Island Sound and the Atlantic Ocean.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Head of the Harbor; river miles along the main stem, rounded.
Head of the Harbor has a hot-summer humid continental climate. Summer afternoons average 83° in July; winter nights fall to about 25° in January. A normal year brings about 32 inches of snow; with the rain, that comes to about 46 inches of water.
On November 14 Head of the Harbor normally reaches 54° and falls to 38°. The record high is 69°, in 1980; the record low 19°, in 1986. The most rain on this date, 2.61 in, fell in 1972.
Normals 1991–2020 and records since 1963 from the Islip Area threaded record (Islip-Li Macarthur Airport, 8 miles south-southeast, 110 ft lower). NOAA, through RCC-ACIS.
