TIL you can't trust a level on a windy day, learned it the hard way on a job in Galveston.
We were setting a big piece of storefront glass, maybe 8 feet tall, on this old building right on the coast. Wind was whipping off the water, nothing crazy but a steady 20 mile per hour gust. I had my level on the frame, got it perfect, and we started to set the unit. The wind was pushing on the glass just enough that it was flexing the whole frame, but my level still showed plumb. We got it locked in, stepped back, and it was visibly off by at least a quarter inch. The wind pressure had tricked the level because the frame itself was moving. Now I always check with a plumb line in any kind of breeze, or better yet, wait for a calm moment. Has anyone else had a tool lie to them because of the conditions?