Acknowledging that weather can be unpredictable, is May (particularly late May) fairly rainy in Paris?
Variable is the word but we have spent many Mays in Paris and it is usually temperate weather with occasional afternoon showers. It rarely pours all day as it sometimes does in say November. We have had good luck with bright sunny pleasant weather -- we don't like it hot and it rarely is in May. We have however had weeks when it was unseasonably cold - e.g. 40sF and we had to turn on the heat. It is a good month in our experience but weather in Paris is always a bit unpredictable.
May is statistically often the wettest month, but that doesn't mean it will rain. It means that if it rains it tends to rain longer than any other month, but it still rarely rains all day, and it's usually not that heavy.
Thank you...you describe the situation well. If you had to choose between May and September, which would you choose?
September for me and not only for the weather.
It depends on what's happening in that particular May or September. If there's something on I want to see that's when I visit. The weather has very little effect on life (even as a tourist) in a big city.
September is said on this forum to be the most expensive month for lodgings in Paris (I assume partly due to conventions and partly due to nice weather??). The days will also be a lot shorter in September than in May.
Acraven, I think the high hotel rates in September come from Fashion Week in Paris.
I would take late May over September. The gardens in and around Paris will be at their very best, and the city will be a bit quieter thanks to the many holidays - especially around 18-21 May and 27-29 May this year.
I am no statistician, but "late May" does not register as a particularly rainy period in Paris for me and certainly not more so than September.