The Riva 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.
Mostly cloudy
Partly cloudy
Mostly sunny
Mostly sunny
Partly cloudy
Mostly sunny
Mostly sunny
81° on Nov. 15, 1993, the hottest reading for this week of the year since 1894. Next is 78° in 1902.
Riva’s center stands about 50 ft above sea level. Within three miles the land runs from 0 ft to 200 ft, a difference of 200 ft: gently rolling country. Open water lies within three miles. The highest named summit within 15 miles is Eagle Hill, about 220 ft, 11 miles north-northeast.
Under the town center the state geologic map shows Pamunkey Group; Aquia Formation (sand), from the Paleocene, 56 to 66 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 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.
Sand. Age: Paleocene, 56 to 66 million years old. About 7 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 4 mi of the line.
Sand. Age: Cretaceous, 66 to 145 million years old. About 3 mi of the line.
Sand, clay. Age: Miocene, 5.3 to 23 million years old. About 0.6 mi of the line.
Sand. Age: Cretaceous, 66 to 145 million years old. About 0.5 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 Riva reaches Chesapeake Bay and the Atlantic Ocean by way of the South River: about 8 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Riva; river miles along the main stem, rounded.
Riva has a humid subtropical climate. Summer afternoons average 86° in July; winter nights fall to about 30° in January. About 44 inches of rain fall in a normal year.
On November 14 Riva normally reaches 57° and falls to 43°. The record high is 78°, in 1993; the record low 18°, in 1986. The most rain on this date, 1.96 in, fell in 1972.
Normals 1991–2020 and records since 1894 from the Annapolis Area threaded record (Annapolis United States Naval Academy Asos, 5 miles east-northeast). NOAA, through RCC-ACIS.
