As you may be aware, temperature are going to drop to a freezing point (32 oF) tonight and tomorrow night in most parts of Virginia (see the freeze warning: http://www.fox5dc.com/weather/freeze-warning_62343395). Most peach and cherry varieties are in full bloom now and this weather might cause a slight damage to the open blossoms, but we are not close to the critical temperatures that would cause serious damage to the crop. Here is the chart of critical temperatures for frost damage.

Source (https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1643&context=extension_curall)

If you would consider turning-on your sprinklers to mitigate the effect of these freezing temperatures, here is the link to my previous post on using sprinklers for frost mitigation (https://blogs.ext.vt.edu/tree-fruit-horticulture/2017/03/12/sprinklers-for-frost-protection-are-they-worth-using/)
As for apple, this cold weather should not be a concern at this this point of bud development. Most apple varieties in our research farm in Winchester are still in the pink or loose cluster stage. Only Pink Lady and Arlet have some clusters with king bloom. Temperatures that would cause serious damage at this stage should be below 25 oF, which is luckily not the case for tonight or for the rest of this week.

Pink Lady in King bloom since Sunday April 15, 2018