The Tustin 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.
26° on Nov. 12, 1938, the coldest reading for this week of the year since 1906. Next is 30° in 1919.
Tustin’s center stands about 150 ft above sea level. Within three miles the land runs from 50 ft to 500 ft, a difference of 450 ft: hilly country. The highest named summit within 15 miles is Pleasants Peak, about 3,940 ft, 13 miles east-northeast.
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 8 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 7×. 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 12 mi of the line.
Sandstone, siltstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 4 mi of the line.
Coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Sandstone, conglomerate. Age: Middle Eocene to Early Miocene, 16 to 48 million years old. About 2 mi of the line.
Sandstone, mudstone. Age: Oligocene to Pliocene, 2.6 to 34 million years old. About 2 mi of the line.
Sandstone, mudstone. Age: Paleocene, 56 to 66 million years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 2 smaller units along the line are not listed.
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.
Tustin has a hot semi-arid climate. Summer afternoons average 85° in August; winter nights fall to about 48° in December. About 12 inches of rain fall in a normal year.
On November 14 Tustin normally reaches 75° and falls to 53°. The record high is 100°, in 1933; the record low 30°, in 1938. The most rain on this date, 1.83 in, fell in 1946.
Normals 1991–2020 and records since 1906 at Santa Ana Fire Station, 2 miles west. NOAA, through RCC-ACIS.