Beaver Creek is another good day trip for this time of year; it's a spring creek so water temps are also going to be consistent (although water *levels* might be low. It's a stream where being there first thing in the morning makes a huge difference at though, as does overcast weather and (1 weird trick!) kind of off-color water from heavy rains. This time of year I'd say your best options will be small streamers fished very carefully, especially in rough water, nymphs, and extremely small terrestials. Depending on how flexible your definition of "Day trip" is and how strongly you feel about trout versus other species, I would also consider the Monacacy for smallies if it hasn't rained recently (good wading spot), Mossy Creek VA (2 hr drive, spring creek so unlikely to have major temp. variations, a very good place to try a tenkara IMO), and the Yellow Breeches/Letort (if you are deranged)/Big Spring (also spring creeks). I haven't fished the PA creeks in a long time, but they do tend to hold water pretty well if it's hot out. Be aware that Mossy has a lot of cattle fields so the water can be off color.