All about timing . . .

My advice is to go when you're ready and not worry about it. If it were three days before Christmas or something I might wait, but otherwise, probably not. There's may be some perfect moment to query, but no one actually knows when that moment is.

While queries occasionally get lost or buried, I'm not sure time of year contributes to that so much as just the specifics of the moment.

Good luck!

There is conflicting advice from agents out there on this topic. Some say they're so busy year-round that it doesn't matter. Others will specifically note they are closed to queries around the holidays.

You might consider sending out your first batch of 5-10 now, if you're sure you're ready, and see if you gets hits or feedback. If you get no hits, then the query might need work, and you'll have time to work on it.

Also, check on the agents' response times on querytracker.net. If agents are known for responding within a week, it might be okay to query now. If it's 4-8 weeks, this might not be the best time to join the slush.

Do it now.

After November, there is a flood of Nanowrimo submissions, and the piles get bigger. The summer, and Dec/Jan tend to be the busiest times by all accounts I've seen. Best to avoid those.

The perfect time to submit is when your work is ready to go, and you feel good about it. As far as agents go there IS no perfect time for them to receive submissions; they always have too many to look at, and a few weeks here and there probably won't make any difference. They'll get to it as soon as they can.

I'll second what hillaryjacques said. I think you should start now with the first and maybe second batch, making sure to send it to people with a reasonable response time so you won't be buried in the slush come the holidays next month. However, you should have in mind that if you're going to wait, you'd probably have to wait until February, because what Ryan Sullivan said about NaNoWriMo is absolutely true. I've seen agents complain about queries that come in December and January a lot, usually regarding not so polished works. You should give your work the chance to stand out instead of being in the middle of 'those'..

From watching QT obsessively, it seems like agents who were really backed up over the summer have caught up and responses are coming quicker now. So I'd go ahead and start. Like someone else said - if you see someone's response time is still 4-8 weeks, you might wait. But lots of agents are getting replies out within a week or two.