How did I miss this thread so far. Texas, Texans and weather are one of the funniest
subjects I know of. I'm native Texan. Grew up near Corpus. Thought I'd moved north and found "seasons" when I moved to College Station

. Lived in Indiana for 5 years, thought that was North, too.
Texas outdoorsfolk and "seasons" are complicated. Most of the Fall outdoor use is on "deer leases" on private land. You also get an up tick in human traffic in the National Forests near you, shotgunner, in the early fall. At least some of those are under State management as far as the hunting goes. So I think there are less folks in most state parks and on rivers and lakes in the Fall. Football and such impacts that too. So not only is camping weather better in the fall, but most parks are less crowded. Down on the coast you get redfish and flounder runs in the Fall that get some attention. After Thanksgiving, most of the hunters are shot out, or worn out, or nowadays out of gas money. Fishing can still be great at times but cold fronts tend to put the bass fishing off a bit. If we get any really cold weather -- read that temps lower than 45 degrees at any time of the day -- the entire state becomes a wilderness. You'll have darned near any outdoor venue (OK, maybe not coastal fishing spots completely) to yourself. Rugged old podnahs with barb-wire scarred faces and tobacco stained stubble will be hunkered down around a stove somewhere if daytime highs are under 50. All the suburban folk are even more sensitive to the "cold". We all need freeking parkas if it gets below 55. Fishing use only really gets going strong in the "Spring" aka January with white bass and crappie runs in freshwater.
Now I've lived most of my life in south central and southeast Texas so to those who want to point out that the Trans pecos, Rio Grande Valley, Panhandle, and Pineywoods, might as well be on 4 different planets as far as people and weather are concerned I understand your point. For example, late winter/early spring bass fishing can be world class on lakes like Falcon and Choke Canyon. Most of what I'm talking about will apply though to the main population centers I think.
So yep, shotgunner, hang on. Things are improving. To my mind the best outdoors months in the state are October through April.
Of course, we've only got so many days coming to us, so I preach getting out whenever you can. I actually like hiking and canoeing in the hottest days of the year. You just have to know what you are doing and adjust your approach. My very favorite time to be out is on a blustery day with temps in the 40's or lower. Buddy, then you own the whole place so to speak.
Tounge in cheek a little on all this, but not much really.
Be flexible and enjoy!