In my climate, May is the rainy season and it rains practically every day. From June to September, temperatures exceed 30 degrees with some thunderstorms, in October it often rains, while the dry period is generally in winter. The plant doesn't even emit a flower here and there.
The GdF from me generally blooms in the first week of June or at the end of May.

It may be my climate. My rose came from a neighbor's original planting from the 1920s. There is a photo of the rose with three young girls in 1924 which is less that a decade from its release into commerce in France. The plant came from Michael Walsh who received it from William Paul. So this plant has only been propagated a few times since its release into commerce by Guillot.

Years ago, I didn't realize it was recurrent for some, so I asked the owner of the house, the daughter of one of the girls in the photograph, if it rebloomed. She said she had never seen rebloom on this ancient plant growing freely over their front door.

Our houses are very close to the sea so we have a very late Spring and late Autumn. Maybe the late Spring diminishes the growing season. We tend to have a very dry July and August as weather patterns across the Eastern USA means that storms generally are north of us. So it seems climate could have a large effect.