The Riverdale Park 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 sunny
Chance of showers
Showers likely; cooler
Sunny
Showers likely
Showers likely
Partly cloudy
80° on Nov. 12, 1989, the hottest reading for this week of the year since 1906. Next is 80° in 1995.
Riverdale Park’s center stands about 70 ft above sea level. Within three miles the land runs from 40 ft to 90 ft, a difference of 50 ft: nearly flat ground.
Under the town center the state geologic map shows Quaternary alluvium and marine deposits (coarse-detrital), from the Pleistocene to Holocene, less than 2.6 million years old.
The section below crosses 2 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 63×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Coarse-detrital. Age: Pleistocene to Holocene, less than 2.6 million years old. About 24 mi of the line.
Coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 0.4 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 Riverdale Park reaches San Francisco Bay and the Pacific Ocean by way of the Tuolumne, the San Joaquin and New York Slough: about 95 river miles.
80 miles of the trip are on the San Joaquin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Riverdale Park; river miles along the main stem, rounded.
Riverdale Park has a cold semi-arid climate. Summer afternoons average 95° in July; winter nights fall to about 39° in January. About 12 inches of rain fall in a normal year.
On November 14 Riverdale Park normally reaches 66° and falls to 43°. The record high is 79°, in 1995; the record low 27°, in 1938. The most rain on this date, 0.89 in, fell in 1968.
Normals 1991–2020 and records since 1906 at Modesto Airport, 5 miles east-northeast. NOAA, through RCC-ACIS.
