I live in San Juan and I can tell you March is a nice time to visit.
Not too hot and the tourist season is pretty much dying off by then.
Try to escape the hustle and bustle of the capital because it's really
congested especially during the weekdays when you can spend up to 45
minutes in a traffic jam on any major thoroughfare.
Some of the nicer places to visit for one day trips near San Juan are
Cayey and Aibonito, which are municipalities up in the mountains and a
lot cooler than San Juan. In Cayey, there is a ward called Guavate,
which is on Road 184 toward the Carite National Forest. There, you can
stop and have a nice lunch at any one of the open air restaurants
where they serve marinated suckling pig "lechon," rice with gandules,
blood sausage "morcilla," and other fares.
The place is filled with music from live salsa and bachata bands.
Another favorite place is the southern west coast municipality of Cabo
Rojo with fabulous beaches Combate and Boqueron. There are ample guest
houses and hotels to stay ranging from $60 to $125 per night. The
place is worth it. But stay away from the area during Spring Break
which is the third week in March unless you're in for a crazy
atmosphere.
Lares in the central part of the island is also a nice town known for
its hospitality as well as its spirit for independence. This is where
the independence movement was born. Nevertheless, independence
supporters are few and far between. The movement is more cultural than
it is political as it was in the 1970s and 1980s.
Enjoy your stay in
PR 
Puerto Rico 
