What signs does nature provide that it's going to rain?

I have heard stories of farmers being able to walk outside, look around the land, and almost certainly determine if a storm is going to roll through that day.

What ways can nature indicate to us that a weather shift is about to happen? What indicators do you use in your environment?

The one way that I notice that nature is telling me it will rain is when maple/oak leaves start to flip over in the trees. Usually that is an indication that rain or a storm is going to pass through soon.

When I walk out the door and smell rain.

When I see dark clouds.

When all the cow are line up against a fence.

When the cat comes inside and hangs around all day even if it is nice outside.

I dislocated my shoulder hitting a diving board during a High School swim meet. I know when it is going to rain or snow from shoulder discomfort. the smell before a storm, the heaviness of the air.

I have read Tristan Gooley's book: The secret world of weather : how to read signs in every cloud, breeze, hill, street, plant, animal, and dewdrop

It is definitely a fun and educational read, but he's in the British Isles, and although he's travelled a lot, I found there are regional differences which I had to apply his knowledge to.

I am glad a upped my game in the "cloud" ID department. The mountains and hills around me, make actual predicting much harder than one might find in other locations. I've had it sunny in the front yard, and pouring rain in the back yard many times - something that was incredibly rare where I grew up.

I can see the weather coming looking into the west.
But there's usually a period of gusts of sudden wind before rain, and if it's a lot of rain that's coming, that wind will carry its smell with it.
Those gusts of wind are giving the homestead person just enough time to gather the tools and whatnot, put them back to place, and to go inside. More often than not, the first drops start to fall as I close the door behind me.