By early afternoon in the East, more than 1,000 U.S. flights had been canceled and 4,000 others were delayed, according to FlightAware. The brunt of cancellations stretched from Denver to Chicago, down to Nashville and east to Buffalo, New York.

Airlines can’t control the weather, but they are still required to provide refunds for customers whose flights are canceled. Here’s what to know about your rights, and what to know when cancellations start piling up:

WATCH THE WEATHER FORECAST

When airlines expect bad weather to create problems for flights, they often give travelers a chance to reschedule their trip by a few days at no extra fee. Google your airline and “travel alerts” or similar phrases to see the offers.

CHECK BEFORE GOING TO THE AIRPORT

It’s better to be stuck at home or in a hotel than to be stranded in an airport terminal, so use the airline’s app or flight websites to make sure that your flight is still on before heading out to the airport. Airlines usually cancel flights hours or even days before departure time.

MY FLIGHT WAS CANCELED. NOW WHAT?

If you’re already at the airport, it’s time to multi-task to find another flight. Get in line to speak to an airline representative, and call or go online to connect to the airline’s reservations staff. It also helps to reach out on X, the site formerly known as Twitter.

Most airlines will rebook you on a later flight for no additional charge. That depends, however, on the airline having empty seats. The good news for travelers this week is that they stand a better chance of finding space in January than during the Thanksgiving and Christmas holiday periods, when passengers can wait days for an open seat.

CAN I ASK TO BE BOOKED ON ANOTHER AIRLINE?

You can, but airlines aren’t required to put you on another carrier’s flight. Some airlines, including the biggest ones except Southwest, say they can put you on a partner airline, but even then it’s often hit or miss. Jeff Klee, CEO of CheapAir.com, recommends researching alternate flights while you wait to talk to an agent.

AM I OWED A REFUND?

If you no longer want to take the trip, or found alternative means of getting where you’re going, the airline is legally required to pay a refund, even if you bought a non-refundable ticket. It doesn’t matter why the flight was canceled.

You are also entitled to a refund of any bag fees, seat upgrades or other extras that you didn’t get to use.

CAN I GET COMPENSATION?

U.S. airlines are not required to pay compensation, even if the cancellation is their fault — such as the lack of a crew, a mechanical problem that grounds the plane, or a computer outage that brings the airline to a halt. However, the Transportation Department is working on a proposal to change that when the airline is at fault.

“I know how frustrated many of you are with the service you get from your U.S. airlines,” President Joe Biden said. “That’s why our top priority has been to get American air travelers a better deal.”

WHAT ELSE WILL AIRLINES COVER?

There is no federal requirement that airlines pick up the costs of hotel rooms or meals for stranded passengers. Each airline has its own policy.

The U.S. Department of Transportation has a site that lets consumers see the commitments that each airline makes for refunds and covering other expenses when flights are canceled or significantly delayed.

OTHER TIPS

If you are in a group and one person belongs to a higher level of the airline’s frequent-flyer program, use the number associated with that person to call the airline, says Kurt Ebenhoch, a travel consumer advocate and former airline spokesman.

If lots of flights are canceled, airline agents will soon be swamped. Try calling your airline’s international help number — usually available online — those agents can make changes in your itinerary too.

Be nice. The agent you’re talking to is probably dealing with lots of other frustrated travelers too, and screaming at the agent won’t make them want to help you. The cancellation isn’t their fault.