The Rockland 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
Mostly sunny; warmer
Partly cloudy
Partly cloudy
Partly cloudy
Chance of showers
Chance of showers
−8° on Nov. 15, 1959, the coldest reading for this week of the year since 1888. Next is −6° in 1950.
Rockland’s center stands about 1,120 ft above sea level. Within three miles the land runs from 900 ft to 1,570 ft, a difference of 670 ft: hilly country. The highest named summit within 15 miles is Trap Hills, about 1,790 ft, 11 miles west.
Under the town center the state geologic map shows Portage Lake Volcanics (basalt), from the Mesoproterozoic, 1.1 to 1.1 billion 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 20×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 12 mi of the line.
Basalt. Age: Mesoproterozoic, 1.1 to 1.1 billion years old. About 8 mi of the line.
Andesite, basalt. Age: Mesoproterozoic, 1.1 to 1.1 billion years old. About 3 mi of the line.
Gabbro. Age: Mesoproterozoic, 1 to 1.6 billion years old. About 1 mi of the line.
Rhyolite. Age: Mesoproterozoic, 1.1 to 1.1 billion 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 Rockland reaches Lake Superior by way of the West Branch Ontonagon and the Ontonagon: about 30 river miles. From there it moves on through the Great Lakes, over Niagara Falls and down the St. Lawrence to the Atlantic.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Rockland; river miles along the main stem, rounded.
Rockland has a warm-summer humid continental climate. Summer afternoons average 78° in July; winter nights fall to about 2° in February. A normal year brings about 180 inches of snow; with the rain, that comes to about 43 inches of water.
On November 14 Rockland normally reaches 39° and falls to 24°. The record high is 67°, in 1999; the record low 4°, in 1911. The most rain on this date, 0.90 in, fell in 1949.
Normals 1991–2020 and records since 1888 at Bergland Dam, 14 miles west-southwest, 180 ft higher. NOAA, through RCC-ACIS.
