Watch hornets nests. If they are high-hard winter, low in the trees-mild winter. Over sized squirrel dens are a good sign also.
My knees on more than one occasion have alerted me that the weather is changing. Unfortunately, this meant rain was coming.
When a high pressure area is approaching smoke from a campfire will rise straight up (It will still rise if the wind is blowing.). Smoke from a campfire will stay low to the ground when a low pressure system is moving in. If you can build a campfire which produces no smoke, good for you ! Keep your rain gear handy though. You may need it.