Tips to help us enjoy a week in Paris if it’s blazing hot!

Stroll through some of the Passages Couvertes. https://parisjetaime.com/article/paris-insolite-les-passages-couverts-a1801

Wear shorts. Lots of people were wearing shorts end of May when it was in the 90s.
Fortunately, they have good water fountains throughout the city to refill your water bottle
I hope your hotel has AC.

Yes, thankfully our hotel has a/c!

All I can suggest is dress light, wear a hat for the sun, move slowly, drink plenty of water, etc. Avoid daytime alcohol. Punctuate your strolls with cafe stops or air-conditioned museums. (I don't know, but I'd guess the remodeled Carnavalet in the Marais would have AC, and it's a great museum for Paris history.) Montmartre might be a little cooler because it's elevated, but you might consider the funicular rather than climbing up the hill.

I wouldn't suggest a trip out of the city just because of the heat, any cooling benefit could be offset by the hassle and discomfort of transportation. Paris is full of parks and shady spots. The suggestion of the passages is a good one too. Our host advises us to "pace yourself, assume you will return." This is good advice in any weather, even better if you want to beat the heat. Have a great time!

Make sure you're not on the top story of any buildings that have slate roofs, of which there are many. There have been videos about the scalding temperatures under the slate.

Oh good to hear the passages are cooler, I have them worked into our plans too! I’m a teacher so for now my traveling has to happen in the summer…looking forward to retiring so I can visit places in the off season when there’s fewer crowds and better weather!

I’ve been in Paris during a heat wave. I wound up going out early in the AM to do outdoor things and then by 3 I was back to my air conditioned hotel with gelato. I would go back out at dinner.

I am going to say this to manage your expectations but the Louvre gets quite hot in the atrium area. Move away from that area and if you want to see things other than the Mona Lisa which is going to be crowded and hot.

As soon as you get to Paris, get a hand fan. I bought these recently and have them tucked in every purse.

https://www.amazon.com/Japanese-Foldable-Collapsible-Decorations-Portable/dp/B0B6HX6J28

The museum air conditioning is not like US museum AC.

Chaesun Portable Neck Fan, available at Amazon and Costco.

This fan is a major game changer in the heat. Hands free use, it is wonderful. I always bring it.

Manage expectations at Saint Chapelle, because you stand in a long slow line outside to go through security.
Also, if the Impressionist art is your priority at Musee D'Orsay, I would get to the museum early and go immediately to the 5th floor, because it gets more crowded as the day goes on. It really heats up and I recall there seemed to be skylights in the roof which in hindsight seems odd because of the art in the rooms...but I'm fairly certain I remember that from two years ago. I definitely remember the rooms up there getting warm.

You will have a great time in Paris, because it's Paris! Maybe take a break mid afternoon to cool down. It stays light so late in the evening. It's wonderful!

Also download the G7 Paris taxi app. My hubby injured his foot while we were in Paris, so it was fantastic to summons an official Paris taxi wherever we were and in Montmarte we took several taxi rides. I could see when you've had enough heat that it would be so convenient, to just have a taxi pull up!

We were in Paris at the end of May, it was the first time we'd ever been there when it was in the 90s. All of the comments above. We definitely moved things to earlier in the day. We did a number of interesting self-guided walking tours, which we could start as soon as we wanted after breakfast. Then, when it got too hot, we did our indoor activities.

We did spend more time in our hotel room than usual, just to cool down, but by the evening it was warm enough to sit at a cafe with a drink, and/or to eat dinner outdoors.

Go to the beach! Google "Paris plages". There's even a couple places you can swim in the Seine.

Go to a sauna. It may sound counterproductive, but you'll get to take dips in the pools and lay out where they'll bring you drinks.

Most of the modern movie theaters have AC. There's nothing like watching a movie in foreign languages. Especially if you can find one that you know. (I'll never forget watching Rambo in German.) Look around the Sorbonne for vintage films.

While the tourist heavy churches get hot can crowded, the smaller, outlining, ones will still be cool inside.

Most of the modern galleries have some AC.

The parks will be crowded, but it stays light out to 10pm now, so plan on finding a place to sit and watch the sun go down and the city light up. The Tulleries is always good, but i especially enjoy the gardens by the Palace Royal in the late evenings; the lighting makes it very romantic.

One last thing, go outside the city center and find one of the large Carrefour supermarkets. Think Walmart, but with a French twist. They have everything from seafood, to clothes (cheap), to books, and restaurants. The wines alone will be eye opening.

Get up early and beat the crowds. Also during the hottest period of the day it's best to take a sieste.

I know people on this forum tend to be quite anti-umbrella, but lately I've found having a sun umbrella really useful for walking around on particularly hot days. You can get ones with reflective coating on the top and they do make a difference. It's nice to have if you're visiting somewhere with no shade, like an archeological site (which I know is less relevant for Paris) or gardens that don't have a lot of trees. Hope you enjoy your trip.

Rule #1: walk on the shady side of the street even if you have to cross the street several times. Stay out of direct sunlight. This is normal for those of us who live in the south of France, not necessarily something Parisians think about I've observed. So be like a southerner.
Ask for a lower-level hotel room, 1-3 floors as counted in French. You want to avoid sunlight directly hitting the wall outside your room, where the stone or cement can absorb the heat and radiate it into your room in the evening. In fall, winter, and spring, you may want a room on a higher floor to make use of the sunlight. Pull the blackout curtains shut during the day if you are on a higher floor that receives direct sunlight. French air conditioning is milder than US air conditioning. Help your room stay cool; don't rely solely on air conditioning.
Do your Montmartre and Marais walks in the mornings, starting early. Break for lunch and then do something else. Neither needs a whole day, but the Montmartre Museum has a lovely garden with a café for lunch. This would be cooler than the stone or asphalt pavement where restaurants are located on Montmartre.
Go to museum evening hours: Louvre on Wednesdays and Fridays, Musée d'Orsay on Thursdays. Check other museums for evening hours.
Check museums for gardens or gardens with cafés: Rodin Museum, Petit Palais, Musée de la Viet Romantique, etc

It’s too late for you to order but if you own any linen shirts or pants, take them! I’m a big believer in wearing things that don’t cling, and are natural fibers to help with the heat. And enjoy Paris.

The problem with a big city like Paris is that the heat gets amplified by the buildings, streets, and the lack of trees and greenery. Plus all the AC units pumping hot air out into the streets. On top of that, daytime heat gets trapped in the concrete and stone, and then radiates back out during the night.

Down in the South, we’re pretty used to this kind of weather. No local in their right mind would risk going out into the city between 1:00 PM and 4:00 PM unless it's absolutely necessary.

In Paris, the forecast for the next few days shows temperatures ranging from 90°F up to 100°F downtown at street level (peaking this weekend). Paris (along with other regions) has been under a heatwave warning since today, which is expected to last until at least next Monday. There's a chance we might even break the all-time heat record for June.

So, do all your street and outdoor activities as early as possible in the morning. Bring plenty of water. Find a place with AC for lunch, and no long walks or strolling through the streets after lunch until 5:00 PM.
You can bring your swimsuits, in addition to the Paris Plage locations, swimming is also possible from today under lifeguard supervision in one part of the Canal Saint-Martin.

In the early afternoon in the South of France and all across Southern Europe, there’s a very popular traditional activity: taking a nap. :-)

We were there during the end-of-May heat wave this year. The hotel had AC but not enough to cool the room and sleep comfortably. We ended up at Monoprix and bought my husband a portable fan with a USB cord. It’s about 8” tall and fits in his luggage easily. We didn’t have too much trouble during the day but nights were pretty tough until the fan.

Plan to do your touring outside in the morning, prior to lunch. In the afternoon, do museums or places where you are mostly indoors.
Also, when outside wear a hat to block the sun. Do keep hydrated.