This story has been updated.

Europe is gradually reopening to U.S. travelers who wish to visit for recreational purposes, as long as they have proof of a vaccine or a negative coronavirus test result, or both. The long-awaited return is being celebrated on both sides of the Atlantic. However, with rules changing so frequently, travelers need to be prepared from the first step (choosing a destination) to the last (returning to the United States). Here is what you need to know if you are considering a trip to Europe this summer.

As of late June, Europe is not fully open, and even saying “partially” is a stretch, because disparate entry rules are complicating multicountry travel. But traveling to Europe this summer is doable — as long as you know what you’re flying into.

“Uncertainty about future last-minute changes to regulations and borders, limited availability, and closures of some places, experiences or activities due to covid regulations may prove challenging,” said Stefan Hellmuth, Europe destination manager for Intrepid Travel, “though traveling to Europe this summer will provide travelers with the opportunity to be a trailblazer for a more responsible and intentional way to explore the continent while helping communities that rely on tourism to recover after the past year.”

Every week or two, the country count changes. Denmark, Spain and France opened on June 5, 7 and 9, respectively. A few weeks later, Germany, Austria, Switzerland and Sweden joined the ranks. Ireland reopened July 19. “It’s very incremental,” said Rick Steves, the Europe travel expert who has suspended his tours until next spring.

Europe is welcoming back tourists

Last year, 6.6 million Americans visited Europe, a plunge from more than 36 million in 2019, according to the European Travel Commission. For months, backyard travel — staycations on a longer leash — has been the primary type of tourism. No surprise, the arrival of the Yanks is a cause for joy.

“On our team’s first trips abroad, we are finding an overwhelmingly positive reception from everyone who see the return of travelers as a sign of better times to come,” said Suzanne McGrory, Europe product manager at Audley Travel.

Scott Keyes, the founder of Scott’s Cheap Flights, and his wife visited Madrid and Valencia in Spain in June. The couple walked into open arms. “We absolutely felt welcomed,” he said. “The sense of relief, especially among tourist-oriented businesses, was palpable.” The hospitality didn’t flow; it gushed forth. For example, they had signed up for a tour of an orange grove estate that was a short train ride from Valencia. The guide saved them the trip and picked them up at their hotel.

Countries are opening at their own rates

On June 18, the European Union gave member states its blessing to lift restrictions on U.S. tourists. (Other countries in the “green” category include Israel, Singapore, Rwanda, Australia and New Zealand.) However, the E.U. added that the individual countries would determine the finer details, such as opening dates and entry requirements.

Several of the E.U.’s 27 countries, such as Greece, Croatia and Cyprus, have been allowing Americans to visit since spring, as have some European nations that are not part of the union, such as Iceland. A few destinations, such as Portugal and Britain, recently had to pause their forward motion to curb rising case numbers.

On July 19, both the State Department and the Centers for Disease Control and Prevention raised the United Kingdom to the highest category, Level 4, due to the rise in covid-19 cases there.

Entry rules and safety protocols are evolving

Entry requirements differ by country, as do mask and social distancing measures, capacity limits and curfews. Italy, for one, recently waived the 10-day quarantine requirement for Americans who have been vaccinated, can present a negative test result or prove that they have recovered from the virus. Previously, only travelers arriving on coronavirus-tested flights were exempt. On June 21, the country lifted its midnight curfew in all regions except for Valle d’Aosta, on the French and Swiss border. Government officials could toss out mask and social distancing mandates in coming weeks. In neighboring France, visitors and residents can forgo masks in most outdoor settings. Capacity limits remain, as well as bans, such as one that prohibits eating or drinking while standing — a très French activity.

“It’s very patchwork and so dynamic,” said Lebawit Girma, a global tourism reporter for Skift. “This is definitely not your hop-around-Europe kind of summer.

Resources can help travelers stay abreast of changes

For the most current and comprehensive information on European Union countries, check Re-open EU, which is run by the E.U., and the State Department, which provides links to covid-related FAQs compiled by its embassies and consulates. Country and city tourism offices are also invaluable, especially during the planning stage. For a broader scope, travel companies and organizations have created interactive maps for the entire world, such as Sherpa, the International Air Transport Association and Kayak, the online travel agency.

“It’s like you are assessing risk on your own,” Girma said. “Once there, you need to stay up-to-date with the news or you could end up getting stuck there.”

The Long-Haul Travel Barometer, an ongoing project by the European Travel Commission and Eurail, found that the disjointed reopening has been tempering enthusiasm for summer Euro travel. According to the report, which covers May through August, nearly 20 percent of U.S. respondents said they were planning a trip in July, 26 percent of participants chose August, and more than 35 percent said they didn’t know when they would make the trip across the Atlantic.

“Travellers from overseas markets are still hopeful to travel but are also cautious to consider Europe as a destination due to the continuous lack of harmonized rules on travel across the region,” the commission stated. “Over the coming months, unity and consistency of safety measures will be of key importance if European destinations are to capitalize on recent positive developments.”

Stick with one country

Until visitors can bounce between countries with ease, experts recommend visiting one country instead of embarking on a Grand Tour. “If you are hellbent on going to Europe, there are two different kinds of trips: One is flying in and out of the same country, so you are dealing with one country’s reality. That’s probably a lot more realistic than a freewheeling trip around Europe,” Steves said. “I think that’s a little premature.”

Hellmuth echoed that sentiment. Although travelers can still book Intrepid’s European itineraries from 2019, he said, “we are putting more emphasis on single-country trips at the moment, as this removes the uncertainty of border crossings during the trip.”

Steves suggests independent travelers take advantage of the local tour guides he uses on his excursions who are eager for work. The guides, whose contact information is posted in his online Guides’ Marketplace, can help visitors navigate the city streets as well as the local, regional and national regulations.

On domestic trains, a Eurail spokesperson said the ticket inspectors will not ask passengers for proof of vaccination. That is not the case on international routes, such as Eurostar. In addition, border control officials may board the train and check for vaccine cards or negative test results.

Most major attractions are back

With lockdowns mainly in the rearview mirror, commercial, culinary and cultural life across Europe is revving back up. Most attractions, including landmarks and museums, are open or plan to reopen within weeks. Take Paris, for instance. More than 50 museums and exhibition venues are open, including the Louvre, Musee D’Orsay and the Picasso and Rodin museums, plus nearly a dozen chateaus, including Versailles. The Eiffel Tower welcomed back guests on July 16. Many places might require advance reservations and have abbreviated hours, so check their websites in advance. The Louvre, for one, informs museum-goers that “all visitors, including those entitled to free admission, must book a time slot.”

Group tours offer a safety net

Travelers who prefer a support system from start to finish should consider booking a group tour. The company will keep track of the regulations for the guests — not that you are absolved from knowing them, too — and do its utmost to remove any obstacles that could disrupt your trip. Audley Travel shares with travelers the entry requirements for each destination it plans to visit this summer, such as Croatia, Greece, Iceland, Portugal, Spain and Italy. “These details are ever-evolving,” McGrory said. “Italy, for example, has just changed some of their rules again, so we’re working on updating our guidance in time for July departures.”

Globus and its three sister travel brands established a criteria for each country when creating their itineraries. The three requisites are: No quarantine requirement, fully operational, and good health and safety conditions. So far, a dozen European countries have passed the test. The company’s comeback trip will be a July river cruise in France.

“It’s so encouraging to see where we are compared to a year ago,” said Steve Born, the chief marketing officer at Globus.

Airfares are surprisingly reasonable

The evolving and sometimes perplexing situation has helped tamp down prices. Keyes said fares are on par with 2019 rates and even lower in some markets. When a country announces its reopening date, he said airfare searches spike. Airlines respond by adding capacity and flights, not raising prices.

“There are more cheap flights for summer than at this time pre-pandemic,” he said, adding that airlines are still desperate for transatlantic passengers. “Long-haul travel is not near to where it was.”

Granted, not all fares are low. Last-minute summer flights to Europe will always be high, no matter what’s going on in the world. To nab a good fare, Keyes recommends booking far out. He said if the country closes its borders, most airlines will allow you to rebook your flight without a change fee and pay only the difference in fare. If the original price is higher, the airline will issue you a credit. You can also keep the flight and use the original destination as a transit point, assuming the country is allowing international flights to land.

“If you see a good deal, book it now,” he said. “And book with the anticipation that today’s rules won’t be tomorrow’s rules.” When asked what he considers a “good deal,” he said a fare from the East Coast in the $800 to $900 range, adding, “I would be thrilled with a summer Europe flight that was lower than $600.”

Hotel rates — and availability — drop in certain markets

Prices for other goods and services, such as hotels, transportation and food, have not budged much from before the pandemic, Hellmuth said. In fact, Expedia has noticed a dip in average daily hotel rates in several cities during specific summer months, such as Athens and Mykonos, Greece, in July; Reykjavik, Iceland, in July through September; Madrid, in late summer; and Paris, in July, before prices start to rise.

STR, a global hospitality data and analytics company, discovered a similar trend across Europe. In May 2019, when the occupancy rate was 75 percent, hotel rates averaged $137 a night. Two years later, the figures dropped to 32 percent and $104, respectively. During the first half of June, rates were about $30 cheaper than the same period in 2019. “With far less demand and really no mix in customer segmentation, there isn’t a great deal of pricing confidence,” said Thomas Emanuel, a director for STR. “The major cities will continue to be challenged until people are confident they can travel without restrictions and we see a return of large meetings, events and conferences.”

While good rates might be plentiful, rooms could be scarce because of a confluence of factors including reduced occupancy, pent-up demand and limited options for travel. “Some destinations are getting short on capacity for the rest of the season,” Hellmuth said, “such as smaller places in Scotland or Iceland.”

Visitors can see Europe without the crowds

With tourism not expected to return in full force until next year, travelers have a unique opportunity to experience Europe without the typical summer crush. The number of U.S. tourists is “teeny. It’s inconsequential,” Steves said. Other nationalities might also sit this season out, such as visitors from Brazil, South Africa and India, which are on the list of high-risk countries. Hellmuth said that although Venice is picking up, especially with the return of cruise ships, overtourism is still a faint memory. He said the City of Canals occupies that sweet spot between ghost town and mob scene. Keyes found an equally subdued scene in Spain, with no lines or crowds. “We went to a flamenco show in Madrid and it wasn’t packed to the gills,” he said excitedly.

Please Note

Potential travelers should take local and national public health directives regarding the pandemic into consideration before planning any trips. Travel health notice information can be found on the Centers for Disease Control and Prevention's interactive map showing travel recommendations by destination and the CDC's travel health notice webpage.

The coronavirus pandemic has disrupted travel domestically and around the world. You will find the latest developments on The Post’s site at washingtonpost.com/coronavirus