The weather is unpredictable everywhere these days. We nearly froze in Paris two years ago in early May. It was so cold that the heat had to be turned on. In years previous to that we have had warm weather in both April and March. As I said, you can't count on the old weather patterns so just take lots of layers whenever you choose to go, but do go. Paris is still wonderful in all seasons.
It really is a coin toss. I have had wonderful weather in March, okay weather in April and cold and rain in May. Every trip was wonderful. This year it will be a March trip. Just go armed with lots of layers and be ready for anything.
I have been there Feb., March, April, May, September and October. I would say September is the best. Feb.-April is cold and rainy. May-late May would be the best, if you are talking of going in the spring, in my estimation. But, Paris is fabulous at any time!
I was in Paris last year in mid-April and the weather was perfect. We expected rain, so I carried a small collapsible umbrella with me daily, but we never saw a single drop. I think we were rather fortunate though, as it is the time of year to expect rain. I continually watched the weather up til our departure and especially the 10-day forcast for Paris just before we left. It helped me to pack accordingly, especially for such unpredictable weather that time of year. Good luck
Weather is always unpredictable except in general seasonal terms. Go in May. We went in April and were disappointed. I think there were two "nice" days out of seven. "April in Paris" makes a nice song title but May is better for visiting.
I was in Paris mid-April 2010, during the Icelandic volanic cloud, and the weather was great. Not a drop of rain, but the folks at the hotel said that was highly unusual. The temps ranged from highs in the 60's to the 80's. Lots of sunburned northern Europeans at Versailles.
The weather patterns change every yr. If you can only go in April, look at the Weather Channel before you go to know how to dress. Prepare for the worst weather and you'll you'll be happy when there is only 1 or 2 days of the rainy weather. Go to a museum those days not Giverny. Enjoy