Weary Louisiana residents emerged to sunny skies this morning as they began to assess the damage wrought by the second devastating storm to roar through in two months.

There were no immediate reports of victims from Hurricane Delta, now a tropical storm, as it churned northeast toward neighbouring Mississippi.

While Delta left hundreds of thousands of people without power in both Louisiana and Texas, damage generally appeared moderate.

In Lake Charles, a city of 75,000 still recovering from the August passage of Hurricane Laura, Delta dumped 40cms (16 inches) of rain, flooding many homes and leaving knee-high water in some areas.

"We're picking up the pieces, but we have quite a road ahead of us," Mayor Nic Hunter said on CNN.

He said Delta's passage so soon after Laura felt like "a double whammy... It's adding insult to injury".

The blue plastic tarpaulins that had been lashed over roofs damaged by Laura were ripped away overnight by Delta's powerful winds in the latest test of residents' nerves and preparations.

Delta was packing 160km (100mph) winds when it rumbled ashore yesterday - classifying it as a Category 2 storm on a scale of five - but by today its sustained winds had weakened to 65km (40mph), the Miami-based National Hurricane Center (NHC) said.

Storm surges of 2.4 meters (eight feet) or more hit Louisiana shores in some areas.

Delta was the 10th significant storm of the year to make landfall in the United States, which forecasters said was a record.

Nearly 600,000 people were without electricity today in Louisiana, according to specialised website PowerOutage, along with 100,000 in neighbouring Texas, whose eastern coast was hit hard by Delta.

Dozens of electricians who had come from nearby states to help restore power after Laura's passage were still in Louisiana and were going to work today to repair Delta's damage.

Laura, a Category 4 hurricane when it hit Louisiana, ripped roofs off houses and uprooted trees, littering streets with debris.

Delta toppled trees and tore down power lines in Mexico's Yucatan Peninsula on Wednesday, but the region escaped major destruction and no deaths were reported.

Delta is the 26th named storm of an unusually active Atlantic hurricane season.

As the ocean surface warms due to climate change, hurricanes become more powerful. Scientists say there will likely be an increase in powerful Category 4 and 5 storms.