Hours earlier, on Facebook and Twitter, Sen. David Vitter, R-La., called the Nevada Democrat "an idiot" for "gravely insulting Gulf Coast residents" with the Katrina-Sandy comparison.
"In my recent comments criticizing House Republicans for threatening to betray Congress' tradition of providing aid to disaster victims in a timely fashion regardless of region, I simply misspoke," Reid said in a statement Monday.
The Senate leader railed Friday after legislation to provide $60.4 billion in emergency funding for New York and New Jersey was killed after House Speaker John Boehner, R-Ohio, refused to let a vote move forward before the expiration of the 112th Congress.
"The people of New Orleans and that area, they were hurt, but nothing in comparison to what happened to the people in New York and New Jersey," Reid said Friday.
"Almost 1 million people have lost their homes -- 1 million people lost their homes," Reid said. "That is homes, that is not people in those homes."
Reid didn't provide his source for the million-homes figure.
New York, New Jersey and Connecticut have estimated about 380,000 homes were damaged or destroyed, Politico reported.
"Sadly, Harry Reid has again revealed himself to be an idiot, this time gravely insulting Gulf Coast residents," Vitter posted on the social networking services Monday.
"Both Katrina and Sandy were horribly destructive storms that caused real human misery. And by most any measure, Katrina was our worst natural disaster in history," Vitter's post said.
Katrina, which struck the Gulf Coast Aug. 29, 2005, caused 1,833 deaths and an estimated $145 billion in damage. Sandy, which struck the Northeast Oct. 29, has been blamed for 131 deaths and $63 billion to more than $80 billion in damages.
About 3 million homes in eight states were without power after Katrina, while 8.51 million homes in 16 states and Washington, D.C., were without power after Sandy.
On Friday a bill to provide $9.7 billion to cover insurance claims filed by people whose homes were damaged or destroyed by Sandy moved through the House and Senate in a compromise after Boehner shelved the original legislation.
The House has pledged to take up the remaining $51 billion in aid Jan. 15. That money would help homeowners and local governments recover costs associated with the storm and help rebuild mass transportation.
The Senate already passed the $60.4 billion aid bill.
But House Republicans outside the Northeast called the measure bloated and without proper oversight.
Reid, in his statement Monday, defended his record in supporting aid after disasters.
"I am proud to have been an advocate for disaster victims in the face of Republican foot-dragging, from Hurricane Katrina to Hurricane Sandy, from fires in the West to tornadoes in the Midwest," he said.
"I have worked hard with Senator [Mary] Landrieu [D-La.] to ensure that the people of the Gulf Coast have the resources they need to fully recover, and I will continue to advocate on their behalf until the region is fully recovered," he said.