The storm made landfall around 12:30 a.m. CDT on the eastern part of the Matagorda Peninsula, about 10 miles west-southwest of Sargent Beach, Texas. Maximum sustained winds were 75 mph with higher gusts at landfall, according to the National Hurricane Center (NHC).
Hours later, Nicholas was downgraded to a tropical storm with maximum sustained winds of 70 mph.
On Monday night, the NHC upgraded Nicholas to a hurricane as its center was 20 miles southeast of Matagorda, Texas.
On the forecast track, the center of Nicholas is expected to move slowly over southeastern Texas Tuesday, and over southwestern Louisiana on Wednesday.
"Nicholas is expected to produce storm total rainfall of 6 to 12 inches, with isolated maximum amounts of 18 inches, across the upper Texas coastal areas into Wednesday," according to the NHC. "Life-threatening flash flooding impacts, especially in urbanized metropolitan areas, are possible across portions of the upper Texas Gulf Coast into far southwestern Louisiana."
In Texas, a hurricane warning is in effect for Port O'Connor to Freeport, and a hurricane watch is in effect for Freeport to San Luis Pass, the NHC added.