The Portsmouth 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
Partly cloudy; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Mostly sunny
Showers likely
82° on Nov. 14, 1999, the hottest reading for this week of the year since 1893. Next is 77° in 2012.
Portsmouth’s center stands about 1,240 ft above sea level. Within three miles the land runs from 1,180 ft to 1,400 ft, a difference of 220 ft: rolling country.
Under the town center the state geologic map shows Dakata and Windrow Formations (sandstone, shale), from the Early Cretaceous to Late Cretaceous, 94 to 113 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 55×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, limestone. Age: Middle Pennsylvanian, 307 to 315 million years old. About 15 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 7 mi of the line.
Limestone, shale. Age: Middle Pennsylvanian to Late Pennsylvanian, 299 to 315 million years old. About 3 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 Portsmouth reaches the Gulf of America by way of Mosquito Creek, the Missouri and the Mississippi: about 1,800 river miles.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Portsmouth; river miles along the main stem, rounded.
Portsmouth has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 10° in January. A normal year brings about 29 inches of snow; with the rain, that comes to about 34 inches of water.
On November 14 Portsmouth normally reaches 49° and falls to 26°. The record high is 82°, in 1999; the record low −6°, in 1940. The most rain on this date, 2.17 in, fell in 1926.
Normals 1991–2020 and records since 1893 at Logan 1 WNW, 15 miles west. NOAA, through RCC-ACIS.
