I have two different wind meters that I use or used to at least. Usually I look at a weather app like you do but you will learn by looking at different things like flags, tree branches or tall grass. Even be able to judge it pretty well just by the feel of it hitting your body. Depending on terrain and your location it usually picks up a little higher off the ground.
How do y'all figure out the wind speed when you're flying? The best I can do if check my Windy app for current conditions, but that is extremely approximate. I'd like to know what winds I'm flying, to better judge what to pull out next time I go out.