It looks like psychedelic art, even though the explanation for the Northern Lights is scientific—the collision of “solar winds" (charged particles drawn by the magnetic pull of the North Pole) with Earth's atmosphere. Also called the aurora borealis, the Lights appear intermittently year-round and are most visible in the darker skies of far northern latitudes during the colder, longer nights of winter. Once you arrive, you need to get away from city lights—which isn't difficult in these five cities—to see the swirling, phantasmagoric greens, purples, yellows, pinks and blues. You will never forget them.

Northern Lights with mountains in the distance in Alaska.

Anchorage, Alaska

Alaska is easily the best place to see the Northern Lights in the U.S. and Anchorage is the logical arrival city, with daily flights even throughout the winter when the viewing is best. If you're bold enough to arrive in the winter, be sure to pack your warmest clothes, even though recent Alaskan winters have had record warm temperatures and record low snowfall totals. Or you can wait for spring, when the Lights are still visible, but for fewer hours. They're seen as early as 8:00 p.m. in the winter, but the best viewing is around midnight on cloudless nights outside the city. Go here for information on Northern Lights photo tours, as well as skiing and dog-sledding winter tours from Anchorage.

Northern Lights along the waterfront in Nova Scotia

Halifax, Nova Scotia

Its location northeast of Maine on the Atlantic shore makes Halifax, the business and cultural hub of the Maritime Provinces, another good spot for admiring the Lights. Before you head out of town at dusk to await their appearance, you can take in this city of 400,000 people, which boasts a two-mile-long waterfront boardwalk and the Maritime Museum of the Atlantic's Titanic exhibit honoring the ship that sank off the coast of Nova Scotia. Afterward, you can drive outside the city to any of these 12 parks, villages or beaches to see the aurora borealis in all its glory.

Green shade of the Northern Lights in Alberta

Edmonton, Alberta

You can gaze upon the Lights anytime during winter in central Alberta, which is easily reached by flying to Edmonton. At 340 miles above the Montana border, you're plenty far north, but far from alone, as Edmonton is a city that has nearly one million residents and its own NHL team and symphony hall. Many spots can be reached from the city for aurora viewing at night. During the day, you can visit the city's attractions—all indoors so they're open all winter—including major art, science, history, aviation, military and telephone museums.

Purple and yellow glow of the Northern Lights in Scotland

Glasgow, Scotland

Situated at a higher latitude than southern Alaska, Glasgow is another English-speaking destination where the night sky dazzles during the winter. “Mirrie dancers" is the Scots' charming nickname for the Northern Lights, which can be seen “dancing" in the skies outside Glasgow and even more so if you drive to the rugged Northwest Highlands of Scotland. Some of the best parklands and coastal stretches for viewing appear here. By day, visitors can take the time to see the sights in and around Glasgow, including medieval Glasgow Cathedral, Loch Ness (home of the mythical creature “Nessie"), Loch Lomond and The Trossachs National Park, Edinburgh Castle, and Edinburgh's Old Town and New Town—a UNESCO World Heritage Site.

Blue shades to the Northern Lights in Iceland

Reykjavik, Iceland

Iceland is one of the hottest destinations on the planet—though not literally—and its proximity to the the Northern Lights is just one reason why. Located farther north than Oslo, Stockholm and Anchorage, the Lights are a common sight there. With most of the island country's population concentrated in Greater Reykjavik, there are plenty of dark spots in the countryside to witness them. There are many tours that take Reykjavik visitors to view the Lights from September to April, ranging from three-hour minibus and boat excursions to week-long tour packages where you can take in all of Iceland's sights.

If you go

United Airlines offers nonstop flights from U.S. cities to all of these destinations. (Seasonal flights to Reykjavik begin in May, but winter connections are available from United airline partner Lufthansa.) Visit united.com or use the United app to see the Lights.