Assabet National Wildlife Refuge has been a good location this year. I went with the Boxborough birders earlier, have been biking there from the S. Acton train station, have taken Lori there, and went this morning again.
There are almost always indigo buntings around and I saw several this morning.
Eastern towhees are also very common there.
Today there was also a scarlet tanager (always nice)
and some blue winged warblers (I saw these last time as well)
according to Merlin, there were also yellow billed cuckoos around. I did not see any. I didn't even really hear them. I'll need to go back and try again.