The worst of the flooding is east of Houston, an area ravaged by Hurricane Harvey in 2017.
Imelda is the first named storm to impact the Houston area since Hurricane Harvey, according to the National Weather Service.
Despite weakening to a Category 1 storm, Dorian still sent seawater surging over neighborhoods, flooding the first floors of many homes.
Florida residents are bracing for the Category 4 storm to hit them next.
On Sunday, Dorian tied the record for the most powerful Atlantic hurricane to ever make landfall as it slammed into the Bahamas.
The 185 mph winds ripped off roofs, overturning cars and tore down power lines.
The storm's maximum sustained winds increased to 160 mph before barreling through the northern Bahamas on Sunday.
The storm is expected to strengthen to a Category 4 this weekend.
The island is still recovering from 2017's Hurricane Maria.
“July has re-written climate history," said the head of the World Meteorological Organization.
Louisiana Gov. John Bel Edwards warned that there could be “a considerable amount of overtopping” of levees.
Scientists warn that heat waves are becoming increasingly common due to human-caused climate change.
Planting season is the slowest in decades as farmers grapple with floods, rains and sodden fields.
The latest round of damaging weather in the central U.S. came a day after violent storms killed one person and injured at least 130 in Indiana and Ohio.
At least three people died in a tornado in Golden City, Missouri, on Wednesday. Extreme weather has also threatened parts of Oklahoma, Kansas, Iowa and Illinois.
An intense storm system swept through Oklahoma, western Texas and southern Kansas on Monday, spawning several tornadoes that caused some damage.