Nearly 52 inches of rain have been recorded in Cedar Bayou, Texas, the National Weather Service reported on Tuesday - a figure that broke the continental U.S. record - as Harvey continues to hit the area.
Meantime, federal and local agencies announced they had lifted more than 13,000 people out of the floodwaters in the Houston area and surrounding cities and counties.
Rains in the region, near Mont Belvieu, Texas, reached 51.88 inches as of 3:30 p.m. CDT. That's a record for both Texas and the continental United States but it doesn't surpass the 52 inches from tropical cyclone Hiki in Kauai, Hawaii, in 1950 -- before Hawaii became a state.
But the National Hurricane Center says that the reading on Tuesday afternoon may be unusual because it was from a low flying hurricane hunter airplane.
Houston Mayor Sylvester Turner on Tuesday imposed a curfew beginning at 12 a.m. to ensure public safety. Police Chief Art Acevedo said violators would be stopped, questioned, searched and arrested.
Houston police have rescued about 4,100 people; city firefighters have saved more than 3,000; and the Harris County Sheriff's Office has rescued more than 3,000 people, according to officials. Meantime, U.S. Coast Guard Lt. Mike Hart says his agency has rescued more than 3,000 people in Houston, but also in outlying cities and subdivisions outside of the city, as well as in surrounding counties, including Brazoria, Galveston and Matagorda.
Harvey has gained strength but has remained a tropical storm. Its winds increased from 45 mph to 50 mph.
Forecasters say heavy rains are continuing to spread over southeastern Texas and southern Louisiana.
Louisiana Gov. John Bel Edwards offered to take in Harvey victims from Texas, and televangelist Joel Osteen has opened his Houston megachurch, a 16,800-seat former arena, after critics hit him on social media for not acting to help families displaced by the storm.
The city's largest shelter, the George R. Brown Convention Center, held more than 9,000 people, almost twice the number officials originally planned to house there, Turner said. The crowds included many from areas outside Houston.
"We are not turning anyone away. But it does mean we need to expand our capabilities and our capacity," Turner said. "Relief is coming."
Edwards said he expects Texas officials to decide within 48 hours whether to accept his offer, which comes as Louisiana deals with its own flooding. About 500 people were evacuated from flooded neighborhoods in southwest Louisiana, Edwards said.
On Tuesday night the U.S. coast guard announced that it saved 4,322 lives in the Houston area since Sunday.
In all, more than 17,000 people have sought refuge in Texas shelters and that number seemed certain to increase, the American Red Cross said.
Turner said the city has asked the Federal Emergency Management Agency (FEMA) for more supplies, including cots and food, for an additional 10,000 people, which he hopes to get no later than Wednesday.
Federal regulators say dozens of offshore oil-and-gas platforms and rigs in the Gulf of Mexico have been evacuated as the storm continues to dump heavy rain.
The U.S. Bureau of Safety and Environmental Enforcement said in a statement Tuesday that workers were evacuated from 102 production platforms -- nearly 14 percent of the 737 manned platforms in the Gulf.
Five of the 10 drilling rigs currently operating in the Gulf also had been evacuated as of noon Tuesday.
The bureau estimated that approximately 19 percent of the Gulf's oil and natural gas production was "shut-in," or temporarily halted, as of midday Tuesday. Offshore facilities will be inspected once the storm has passed.
The Texas Gulf is a key area for U.S. oil refineries and oil and gas production.
Homes northeast of Houston, meantime, have been evacuated after a chemical company warned of a risk of an explosion at its flooded plant.
The Harris County Fire Marshal's office said in a tweet Tuesday that homes within 1.5 miles of the Arkema plant in Crosby have been evacuated out of precaution.
In a news release, Arkema said that it manufactures organic peroxides in Crosby, about 25 miles northeast of Houston. The company says the chemical compounds must be stored at low temperatures, but it lost refrigerated storage after power went out and backup generators were inundated.
Arkema said it shut down the Crosby site before Harvey made landfall last week, but a crew of 11 had been kept onsite. That group was removed Tuesday.
The Associated Press contributed to this report.