The other thread (balancing travel while still working) got me thinking on this. Now that we are no longer tied to kids’ school schedules, we can technically travel whenever…that said, my travel window, based on preference is still kind of narrow. We live at the beach, so I hate to be away for long from Mem Day Weekend through the end of October. I also like to be home for the late autumn/winter holidays 
, which basically leaves early November, and January-May. We consistently go somewhere in March, which tends to be the best weather at many of the tropical destinations, and a less crowded/cheaper/milder weather (though sometimes rainy) time to visit may European cities. Of course, the particular destination often dictates when we go (e.g., a visit to Glacier NP will be in summer, for obvious reasons), but if I had my way, all of our travel would be in the winter and spring.
Our summers and fall are beautiful right here. So…we prefer not to travel far during these times.
We also prefer Fall and early Spring - the “shoulder season.” I wouldn’t be opposed to going in the winter either. I HATE traveling in the summer and only do it when we don’t have any other choice.
I live in the upper Midwest. The summers are usually very pleasant ( this year is an exception) and winter is long and cold. I don’t like to leave town in the summer ( I also have zero interest in traveling when it’s hot, not to mention the crowds).
I like to travel in late October/ early to mid November as well as in February and March. I am currently booking a NYC meet up with a friend in early November and have a yoga retreat week coming up in early March.
Possible plans are: Florida and / or Hilton Head in February/ March ( friends in both places), and SoCal late December ( my sister is there).
If there is a flight from PAE to somewhere… that’s when and where we travel. I detest flying from our overcrowded, under constant construction larger airport.
Mid November. Oddly specific I know
November 15-December 1 is deer hunting, gun. I dislike it so much that I try to be gone
Been pretty successful.
I’d like to add March to the schedule but so far, that hasn’t been as successful.
We used to take a long trip in the summer, but because it’s getting so hot everywhere, we now go in the shoulder seasons. 
I’ve been wondering how soon before “shoulder seasons” get more crowded than “high season” in some places (Italy, Greece, for example).
I think it’s trip and time dependent too. An early December cruise might be 1/4 the price of a Christmas week one.
If your goal is less cost, kids and more quiet, it can be great.
If the goal is holiday kids and energy, holidays can be great.
Really trip dependent. .
We normally go on a trip around March connected with lobbying in DC plus one in May connected to a national medical conference. In the fall we generally have a trip around September/Oct/Nov related to my volunteer activities. We add extra stops to see family/loved ones in NYC, SF, or whatever sounds fun to us. We sometimes do international tours, especially if friend/family is also going.
We tend to plan our bigger trips for early May or October. The last two trips to Europe we left late April, early May and we had some cool weather. October is the nicest month where I live. The pst three years we have done a camping trip coming in on Labor Day. The campground is pretty empty.
We’ve done our last few hiking/sightseeing trips in England and Spain in late April/early May and late September/early October. It’s lovely then.
I have friends there too, and I’m happy to go whenever they invite me but do love March -May (not during the Heritage as I don’t like people on my vacations) or Oct.
That’s my problem. I don’t like people on my vacations. I don’t like the water too hot (too many critters like sharks, jelly fish, stingrays - when I went 2 years ago there were all those things and alligators, owls, bats). I want my paradise to be PARADISE. For free. It all needs to be free.
When possible, I like “shoulder” seasons where there are fewer people and it’s not freezing nor boiling. You also tend to get getter fares and deals, but I am somewhat limited by meetings that I attend which others set. When I visit family & loved ones, we normally stay with them do lodging is free and we pay for many meals.
I’m approaching 60 and work with a lot of people with young kids so I always try to schedule my time off when others don’t want that time. So typically April/May Sept/Oct.
My husband would tell you the third week of January, because apparently that’s typically the coldest week of the year where we live.
We do typically like to go someplace warm when it’s cold where we are.
Neither husband nor I like really hot humid weather, so we try not to go south in the summer, for example.
We do want the place we’re going to have fairly good weather (defined as not too hot and not too cold, preferably with little rain and usually no snow) while we are there, so it really depends on the place.
If we can avoid huge crowds, that’s a plus for us, so going to the beach during the time school is out wouldn’t be on the top of our list.