I find
WebPageTest to be useful for these kind of situations. When the USNO was causing the problem, I could see 30+ seconds of lag, then everything loaded in rapid succession afterwards. (apparently after a time out)
I have since disabled USNO, since this issue seems to recur and severely affects page loading. Whatever small error exists in the estimate for sunrise/set doesn't matter to me, vs this issue.
I just re-ran it and found that a Facebook
js was causing a loading issue. I was able to comment it out. (it wasn't showing anyways)
I also made the CoCoRaHS logo local to my web server instead of pulling it from CoCoRaHS. Between the two things, I shaved off about 3 seconds in load time.
Greg H.