Dude, where you from, Nunavut? Just kidding, I know you're from California, but don't know where. Maryland is not that hot in May. At least not this part, it's smack dab in the middle of the Appalachian Mountains. Yes, not the Rockies, and not even a particularly high section of the Appalachians, but a very scenic area. And in my opinion, not very hot.
If I recall, he lives on the coast in central California so might like the coastal area of Maryland as well. I am quite familiar with the area that he lives and although it has beaches and waves it's quite a bit different than the pacific coast. I've driven down the Delmarva peninsula several times and there are some real nice areas there. On the other hand, May to late September is also mosquito season and they can be pretty plentiful. September and October are pretty much may favorite months on the mid-atlantic coast (and, actually, just about everywhere).
Central Coast, California is home. Temps usually between 45 and 65, year around. I haven't run my furnace since 2000. When the air gets into the 80s I look for a cool place to hide and redwood groves are excellent for that as they do some weird cooling thing with air and moisture. Our relative humidity is usually under 50 percent.
For most of my life I lived in the Midwest and during Summer, except on those rare cool days following a cold front passing through, we tended to get the outside stuff done before 10 AM and spend the middle of the day at the pool or in the basement. My great uncle (Rear Admiral USN) and his wife are buried at Anapolis and I visited the panhandle, Baltimore and Anapolis areas a few times, May to early June, as we made arrangements for memorial and disposal of estate. The heat was intense, the humidity was also, even worse than Michigan, which was a new experience to me.
It's easy to put on layers when it's cool or cold, but hard to peel past your unmentionables when it's too hot. I endured Florida, but I've no intention of repeating that experience. If they'd consider Autumn GeoWoodstocks I'd be there in a flash. I have many fond memories of the East Coast in Autumn.
Take a suggestion from me. Bring a jacket with you and also bring shorts. I spent the first 30 years of my life in Hagerstown and on Memorial weekend it can be 40 degrees or it can be 85 degrees. Also trust me, Memorial weekend is a much better choice weather wise because July 4th can be miserable due to heat and humidity. Also for those of you relating Hagerstown to Washington D.C. well it about 70 miles west (but it seems a world away LOL) in a valley between 2 mountains and Boonsboro is farm country. Not a bad place to visit, just didn't want to live the any longer
