The powerful storm moved over land near Matagorda around 4am local time (7pm AEST) on Monday, the US National Weather Service said.
Beryl was about 135km south south-west of Houston, packing maximum sustained winds of 130km/h, the National Hurricane Centre (NHC) said, adding the storm was now expected to weaken.
"Beryl is expected to weaken to a tropical storm later today and to a tropical depression on Tuesday," the NHC said in its latest briefing.
A total of 120 counties in Texas have been declared disaster areas ahead of the storm hitting. (AP PHOTO)
Beryl, the earliest category 5 hurricane on record, last week swept through Jamaica, Grenada, St Vincent and the Grenadines, toppling buildings and power lines and killing at least 11 people.
The storm weakened after its deadly trail of destruction across the Caribbean, but strengthened into a category 1 hurricane as it crossed the warm waters of the Gulf of Mexico. Category 1 storms generate winds up to 153km/h.
Acting governor Dan Patrick on Sunday declared 120 counties to be disaster areas ahead of the storm and warned Beryl "will be a deadly storm for people who are directly in that path".
School systems - including the state's largest in Houston - said they would be closed as the storm approached.
Airlines cancelled hundreds of flights, and officials ordered a smattering of evacuations in beach towns.
Airlines have cancelled flights and major oil-shipping ports have closed in preparation. (AP PHOTO)
Closures of major oil-shipping ports around Corpus Christi, Galveston and Houston ahead of the storm could disrupt crude oil exports, shipments of crude to refineries, and motor fuel from the plants.
Most of the northern Gulf's offshore oil and gas production is east of Beryl's forecast track.
Some oil producers, including Shell and Chevron, had evacuated personnel from their Gulf of Mexico offshore production platforms ahead of the storm.
Citgo Petroleum said it plans to keep the Corpus Christi refinery running at minimum production as the storm moves up the coast.
Gibson Energy, which operates a large oil terminal in Corpus Christi, said operations were continuing, but it would take further steps depending on the forecast.
With Reuters
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