I learned in college the even early May can still have a lot of snow. I read a lot of reports, and when I see people write things like "lots of snow still up there. We were post holing past our knees" I assume that it's a rude wake-up call when the lower section of the trail is bare. The RMC weather report from Thursday said that there was ice above 3300', so that's a decent gauge of Northern slopes for a trail that is used all year. What it comes down to is knowing what to expect is a skill to learn, piecing together trip reports and snow stake information, in combination with your experience. Sometimes you get a great trip report that spells everything out for your hike, and sometimes you have to extrapolate for older reports in the same area. The website
trailsnh.com gives a nice compiled list of reports. Not all reports are created equal, as many are bragposts/blogposts that aren't written for the benefit of others, but most are very helpful with conditions and are enjoyable to read. You learn who is who after a while.
When it comes to April, the overnight lows are important so you know if the pack froze over. A hiker might be able to bare boot in the AM, but need shoes for the descent. Also, you might have an easy rock hop in the morning and a ford by the afternoon. Gators and shorts is always a good look.
As for a direct suggestion, I bet that Flat Mountain Pond is a good hike right now. The crux would be the stream crossings on the northern end of the loop, and the beaver flooding by the hairpin turn on the southern end of the loop (which can be avoided by a short bushwhack to the west). An out and back from the South would avoid the potentially more dangerous crossing of the Whiteface River. The best benchmark for that crossing is probably the Bearcamp River in Tamworth (
https://waterdata.usgs.gov/nh/nwis/uv?site_no=01064801). When I did it a couple years ago after a rain storm the gauge was about 200cfs and the crossing was a rock hop, slightly downstream from the main crossing. Right now, the gauge is just under 500, so I'd expect that crossing to be difficult. Hope that helps!