We hope to visit Paris for the first time in 2026. What months are best for weather and being able to access all of the popular sights without to much congestion?
Nobody with an ounce of sense is clicking that link.
OK to click it; it's just a link to Rick Steves' Paris/France guidebooks. The OP is also familiar with them as she used them for trips to Turkey and Greece.
"Best" is a subjective term but while you're waiting for some other travelers to chime in, Rick has this to say about when to go:
https://www.ricksteves.com/europe/france/paris-itinerary
Depends on what you think is 'best'? Do you like it hot? Summer is for you.
I was in Paris last March - landed on the 18th. I had one week of absolutely perfect weather - in the 60s/low 70s, no rain until the weekend. After I left, the bottom dropped out and it became a super soggy spring. ymmv.
for us it is spring and fall. When we were working we came in May because that was a convenient time in our schedules. Now we come in April/May and September/October. IMHO mid September through October is most reliably pleasant but not hot.
Here's my Chime. I have enjoyed the last week of May into the first week of June (twice), the first week of September & the first week of October. November & December I was there for the holiday season, so I knew I was going to get cold & only a few times wet weather. This year I will be enjoying the entire month of October in Paris.