12 Things to Do in Paris During a Heatwave (That Won’t Roast You Alive)

France is on its fifth heatwave of 2026. Paris hit 38°C last week, and the Loire Valley topped 40°C. If you’re visiting right now, the plan changes.

Not because the trip is ruined. Because doing Paris in 38°C heat the wrong way will wreck you in about two hours.

These 10 ideas all pass the heat test.

Galeries Lafayette

The main building on Boulevard Haussmann is fully air-conditioned and worth a few hours even if you buy nothing. The 1912 Art Nouveau glass dome at the center is one of the most photographed ceilings in Paris, and visitors photograph it from the street entrance and leave.

Go up. The building has nine floors of shopping, a rooftop terrace with a free view of the Opéra Garnier, and a food hall that can hold you for a serious lunch. Come back down when the temperature outside has dropped.

Swim in the Seine

This is new. As of July 4, 2026, Paris has three official free swimming spots directly in the Seine: one at Bercy in the 12th, one under the Pont Louis-Philippe in the 4th right in the historic center, and one at Bras de Grenelle in the 15th with a view of Paris’s smaller Statue of Liberty. All three are supervised, water quality is tested every day, and they cost nothing.

A century-old ban reversed itself, and most visitors have no idea this is possible. Check paris.fr/paris-en-seine-2026 the morning you go, as brief closures happen after heavy rain.

The Catacombs

Twenty meters underground, the Catacombs hold at a constant 14°C year-round. That’s 57°F. When it’s pushing 40°C above ground, walking down those 130 steps is one of the best decisions you’ll make all day.

The tunnels hold the remains of over six million people, moved here from Paris’s overcrowded cemeteries in the 18th century. It’s eerie, and cold. Book your ticket online before you go. The outdoor queue in direct sun is not where you want to stand.

A Champagne Cellar in Reims

Reims is 45 minutes from Paris by TGV from Gare de l’Est. Pommery, one of the great Champagne houses, runs self-guided tours through 18 kilometers of chalk tunnels carved 30 meters underground, where the temperature holds at 10°C year-round. That’s colder than most refrigerators.

The cellars are UNESCO-listed and filled with contemporary art installations. You end with a tasting. Tickets start at €30 and the cellars are open seven days a week. Book your slot in advance because they fill weeks ahead in summer.

Sainte-Chapelle

The walls of Sainte-Chapelle are almost entirely replaced by 1,113 stained glass windows across 600 square meters. On a sunny August afternoon, the upper chapel fills with colored light unlike any interior you’ll find anywhere.

The Gothic stone keeps it cool. Tickets are €18 online. It’s on the Île de la Cité, five minutes from Notre-Dame, and you can combine both in a morning before the heat peaks. Book a timed entry. The outdoor queue can be long in peak season.

Les Caves du Louvre

A short walk from the Louvre, this is a network of 18th-century wine cellars built for King Louis XV, sitting at around 10°C underground. You go down, a sommelier walks you through French wine regions, you taste three wines, and you come back up two hours later into a city that’s still cooking.

Visitors consistently describe it as the perfect midday escape. Sessions run most afternoons. Book online.

The Musée de l’Orangerie

The Louvre is not reliably air-conditioned, and the crowds generate enough body heat to cancel whatever cool air exists. The Musée de l’Orangerie, a short walk away along the Seine, is different. It’s smaller, properly climate-controlled, and it houses Monet’s Water Lilies in two oval rooms purpose-built for them.

Standing in those rooms in a heatwave, in the cold, surrounded by eight enormous canvases, is not a bad way to spend two hours. Book ahead online.

The Musée d’Orsay

The Orsay runs cooler than most Paris museums. The building is a converted 19th-century train station, and its ventilation system keeps the galleries at a noticeably lower temperature than the street. It also has the greatest collection of Impressionist paintings anywhere, including the largest Monet, Renoir, and Degas holdings you’ll find under one roof.

Go on a Thursday, when it stays open until 9:45pm. The afternoon crowd thins out after 6pm and the temperature outside finally starts to drop. Book online and skip the queue.

A Seine Dinner Cruise

The enclosed lower deck of a Bateaux Parisiens dinner cruise is fully air-conditioned. You board near the Eiffel Tower, you eat a three-course French dinner on the water, and for two hours you watch Notre-Dame, the Louvre, and the Pont Alexandre III slide past through glass panels. The Eiffel Tower sparkles on the hour after dark.

Dinner cruises run from around €75 per person. Evening departures mean the outside air has started to drop too. Stick with Bateaux Parisiens or Bateaux Mouches. At least one reviewer on TripAdvisor this summer reported a different operator promised AC and delivered a floating sauna.

The Hammam at the Grande Mosquée de Paris

The Grande Mosquée in the 5th arrondissement was built in 1926 and houses the largest hammam in Europe, at 550 square meters of mosaic, marble, and vaulted ceilings. Entry is €30 and includes a towel and mint tea.

Yes, a steam room sounds like the wrong call in a heatwave. The point is the cold plunge after, and the shaded marble courtyard where you sit with tea and pastries when it’s done. It’s one of the most beautiful spaces in Paris and you’ll leave significantly cooler than when you arrived. Women go Monday, Wednesday, Thursday, Saturday, and Friday afternoon. Men on Tuesday and Sunday. No reservations needed.

The Palais Garnier

The Paris Opéra is air-conditioned, its interior is among the most spectacular you’ll find in any city, and the vast majority of tourists never go inside without a performance ticket. That’s a mistake.

A self-guided visit costs €15 and takes you through the Grand Staircase, the Grand Foyer with its floor-to-ceiling gilded mirrors, and the auditorium with its Chagall ceiling, when rehearsals aren’t running. The building opened in 1875 and the whole thing reads like a fever dream of marble, velvet, and bronze. Americans who’ve seen Phantom of the Opera tend to go slightly quiet when they walk in. Book online and go in the afternoon when the heat outside is at its worst.

D-Day Beaches, Normandy

This one takes a full day, and it’s worth it. Air-conditioned coaches and minivans depart central Paris every morning and reach the Normandy coast in about two and a half hours. Coastal Normandy runs 6 to 8 degrees cooler than Paris during a heatwave, consistently.

The Mémorial de Caen is fully air-conditioned and widely considered the best World War II museum in France. It covers the causes of the war, the D-Day landings, and the Battle of Normandy in depth, and the current temporary exhibition is free specifically because it’s in an air-conditioned wing. The beaches, Omaha, Pointe du Hoc, and the American Cemetery at Colleville-sur-Mer are outdoors, but standing on Omaha Beach in a French summer, even a hot one, is something else entirely.

Tours with English-speaking guides depart daily from Paris. Most include the Mémorial and two or three beach sites.