After a few years of frost damage to our fruit trees, I was concerned that we would have the same problem this year, even though the trees are far less advanced than they were in 2012, where the warm spring made them much more vulnerable to a frost. There is an interesting series of Critical Temperature Charts on the Colorado State University site which explain at which point the fruit is most likely to be damaged by frost. Generally, once the buds are fully opened, a temperature of -2°C/28°F will kill 10% of the flower buds, while -4°C/25°F will kill 90%. That's what happened last year, but we weren't close to that last night, so I'm hopeful.
The apricot tree flowered last week and there are embryonic apricots already visible:
The pear trees are fully in flower right now:
While the apples are at the stage known as 'full pink':