It may be a “cruel summer” for air travelers – thanks, in part, to Taylor Swift.

According to United Airlines, demand for travel to Lisbon, Portugal and Madrid, Spain, where Swift is performing for her “Eras Tour,” is up about 25% in comparison to last year.

A spokesperson for United said the airline has also noticed spikes in air travel to other European cities where the singer is performing this summer, including Edinburgh, Dublin, Milan and Munich.

American Airlines also said it has noticed the increased demand.

“American Airlines knows ‘all too well’ the places Swifties are fearlessly flying to this summer with increased demand on transatlantic flights to Zurich, Milan, Munich, Amsterdam and Dublin,” a spokesperson for American said Wednesday.

Opening night of Taylor Swift’s ErasTour in Glendale, Arizona.(Credit: Kevin Winter/Getty Images for TAS Rights Management)

Thousands of Swift fans or “Swifties” who missed out on her U.S. concert tour last year or didn’t want to purchase exorbitantly priced tickets to see her again found that flying to Europe was an out-of-the-way solution.

Fans follow Taylor Swift to Europe

Some North American fans who plan to fly overseas for the Eras Tour said they justified the expense after noticing that tighter restrictions on ticket fees and resales in Europe made seeing Swift perform abroad no more costly — and potentially cheaper — than catching her closer to home.

“They said, ’Wait a minute, I can either spend $1,500 to go see my favorite artist in Miami, or I can take that $1,500 and buy a concert ticket, a round-trip plane ticket, and three nights in a hotel room,” Melanie Fish, an Expedia spokesperson and travel expert, told the Associated Press.

RELATED: Taylor Swift breaks Spotify single-day records

The 34-year-old singer kicked off the European leg of her tour earlier this month. Her last stop will be in London in late August, before she leaves to perform in Canada for the remainder of the year.

Swift broke Spotify’s single-day records last month after releasing her latest album, “The Tortured Poets Department.”

Swift became Spotify’s most-streamed artist in a single day in Spotify history, with her 11th studio album also becoming Spotify’s most-streamed album in a single day in their history, Spotify announced.

Airlines gear up for busy Memorial Day weekend

This news also comes as the airlines gear up for a busy travel weekend for the Memorial Day holiday.

United said it forecasts that the Memorial Day weekend will be its busiest on record with more than 3 million passengers expected to fly between May 23 and 28 – up more than 5% compared to last year.

United also said it anticipates it will have its busiest summer season ever with 5% more customers flying the airline this June, July and August.

This story was reported from Los Angeles.