That's quite a change, and that it happens in just about 48 hours surprises me a little.
It reminds me of a relative who is in Toronto and complained a while ago about how quickly the weather changed when compared to other places in the world. Well, it could happen that in one week it would start with freezing temperatures, and the next day would have so much sun and heat that you wouldn't believe there was even snow a few days ago.
Although that seems to happen with seasonal changes, because otherwise the climate where she is is usually well below zero for more than half the year.
RE: Memorial Day flowers