So what type of conditions will you NOT go shoot in? As for the wind, at what point do you stay home? At what point does the wind cause problems with being able to shoot good groups at 100 yards!

It really depends on how the conditions will be at the range. That being said the wind always blows here so it has to be constantly over 25mph to be a deciding factor.

If you have time to shoot, go shoot.

100 yards is so close that tornado conditions are what it would take for me to stay home. I always write down the environmental conditions, it's amazing what you can learn when you pay attention to changes your ammo makes in various conditions. That is, if it changes at all.

Steady wind conditions are not an issue for me when testing new loads, gusting winds are another matter. With gusting winds groups can be more like a weather report.

Bitter cold and rain keep me home. Wind is good to work in,
you should take notes on your new 100y poi.

Would not worry about the wind as much as the windchill during this time of the year. Also other variables will determine groups, ie, caliber, weight of bullet, type of bullet, actual FPS, etc. I can handle wind better than bugs.

In prior years, I've shot through some miserable conditions... even in the rain. These days, with different priorities at the range, I pick better days. If a range day comes and the weather is foul, I stay home and use the time to knock out something else that needs to be done. Wind usually isn't a big issue for me, but if it's cold & wet, I'll think twice... or in the case of the way it's been during the last few summers around here if it's 1,000 degrees outside, I'll think twice.

I like shooting in cold weather (within reason). The barrel cools much faster. As long as I'm not shivering and my nose isn't running and dripping on the stock, I'm Ok. And I don't see that a little wind at 100 yards makes that much difference, unless you are trying for the best groups you ever shot so you can impress your buddies.

Face it...you're gonna hunt in bad weather. Can't hurt to practice in bad weather.

Since you mentioned good groups then I will say 15mph and above will most definitely have an impact on groups even at 100 yards. This does not mean you cannot shoot very good groups but you better pay attention to the wind and wind flags will help.
You did not mention caliber but smaller is affected more than larger but all are subject to open up slightly.
If you are making decision’s on a load then wait for better IMO.

Pay the most attention to vertical dispersion of your groups. That is what will tell you the most if the barrel likes the load. The wind won't effect vertical dispersion much at 100 yards. Especially a head or tail wind. I hate head or tail winds outside 300 yards, but don't think twice about them at 100 yards.

I like to shoot in conditions that are similar to what I hunt in. Windy, cold, rainy, etc. It's the best way to know what your bullet is gonna do.

My approach is to do shooting for load development in the best conditions possible, but once the load's done practice in not-so-good conditions is appropriate.

A 10 mph cross wind will push a typical 308 bullet .6". So, not much at 100. I prefer to shoot in 10 mph or less when testing loads out to 200 and 300 yards.

I never go to the range if the wind is over 5mph.

So you don't shoot very often, then.

I gave up on waiting for those conditions, and adapted.

Never is a bad day to shoot. I enjoy busting a cap and if I have to work its more like hunting

70 years old, hunted deer in Texas for 57 years, have kind of kept a running average of the range my deer were killed, 87 yds. Cold, Wet, Dry, Hot, Windy, No Wind..... 87 yds. So go to the range, site it in at 100 yds, 1.5 in high regardless of the weather.....go hunting. Only two deer in the average over 400 yds, can't see that far anymore.

I shoot on my own 100 yd range, and I shoot whenever the mood strikes me. I can shoot decent groups in a high wind if I take my time. And like I said earlier, cold is good, since it cools the barrel down quickly. That beats shooting test groups in July, when the barrel might cool by the next day, if you put it in the shade.

Also, a note about load work up in the winter. If you are using a temp sensitive powder, do not run a max or over max load. By the time summer comes, you WILL have a hot load. I did a rifle in 270 WSM for a customer, and he provided the Mag Pro powder to use, since it was listed as the highest velocity of all the powders. He wanted it fast, so that's what we'll do. We got a 130 grain bullet screaming at 3350 fps in the cool, fall time temps and shooting very accurately. Summer time comes, and he is locking up the bolt and the groups are all over the place. Any of your ball powders, and non Hodgdon Extreme powders will exhibit this. I prefer to work up loads in about 50 to 60 degrees for this reason.

What's not mentioned is some ranges like ours have side berms which block winds from one side as does the berm behind the target. Also if the wind is head on or from the rear at 100 yds with heavy projectiles (not Varmit wgt) affects will be minimal. Hunting is not where you get to always chose weather conditions and it doesn't hurt to practice in adverse weather. When I used to compete and referee at Skeet almost every year the State Shoot and World Shoot we'd be shooting in high winds or rain or both. Those who were a little timid about getting wet didn't fare well.