The McHenry 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
Mostly cloudy
Chance of showers
Partly cloudy
Chance of showers
71° on Nov. 14, 1939, the hottest reading for this week of the year since 1909. Next is 69° in 2005.
McHenry’s center stands about 1,510 ft above sea level. Within three miles the land runs from 1,490 ft to 1,560 ft, a difference of 70 ft: gently rolling country. The highest named summit within 15 miles is Devils Thumb, about 1,730 ft, 7 miles north-northwest.
Under the town center the state geologic map shows Pierre Formation (shale), from the Late Cretaceous, 66 to 100 million years old.
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.
Shale. Age: Late Cretaceous, 66 to 100 million years old. About 24 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.
McHenry has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about −1° in January. A normal year brings about 60 inches of snow; with the rain, that comes to about 21 inches of water.
On November 14 McHenry normally reaches 37° and falls to 20°. The record high is 71°, in 1939; the record low −16°, in 1940. The most rain on this date, 0.80 in, fell in 1944.
Normals 1991–2020 and records since 1909 at Mc Henry 3 W, 2 miles west. NOAA, through RCC-ACIS.
