Sounds like wilt due to water loss that is happening faster than the roots can take it up. Since the flowers are the furthest from the roots, they are typically what suffers first. I have seen this happen in my garden when we have had cool weather and then the weather turns much warmer very fast and the air is relatively dry. It is almost as if the plant is not ready for the weather change and the flowers wilt first.

I believe you're right, that is exactly the kind of weather we're having. Not only that, the wind has been blowing a gale here for 2 days now.