The Holly 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.
1° on Nov. 13, 2019, the coldest reading for this week of the year since 1921. Next is 7° in 1933.
Holly’s center stands about 930 ft above sea level. Within three miles the land runs from 890 ft to 1,060 ft, a difference of 170 ft: gently rolling country. The highest named summit within 15 miles is Pine Knob, about 1,260 ft, 14 miles east-southeast.
Under the town center the state geologic map shows Marshall Sandstone, from the Carboniferous, 324 to 359 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 48×. 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. Age: Carboniferous, 324 to 359 million years old. About 11 mi of the line.
Sandstone. Age: Carboniferous, 324 to 359 million years old. About 9 mi of the line.
Shale. Age: Carboniferous, 324 to 359 million years old. About 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 Holly reaches Lake Huron by way of Swartz Creek, the Flint, the Shiawassee and the Saginaw: about 110 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 Holly; river miles along the main stem, rounded.
Holly has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 16° in January. A normal year brings about 52 inches of snow; with the rain, that comes to about 32 inches of water.
On November 14 Holly normally reaches 47° and falls to 31°. The record high is 66°, in 2009; the record low 12°, in 1986. The most rain on this date, 0.87 in, fell in 1957.
Normals 1991–2020 and records since 1921 from the Flint Area threaded record (Flint Fcwos, 14 miles north-northwest, 160 ft lower). NOAA, through RCC-ACIS.