Can I make my new copper weather...

If you’re looking for that green-tint effect, an effective method is to bury the vane in a pile of manure for two weeks — but you may have some explaining to do to your neighbors.

As an alternative, you can try soaking or spraying the copper with a solution of salt and vinegar. Over time, the surface will turn a greenish blue. When it reaches the color you like (hours to days), remove it from the solution (if soaking). You might want to then rinse, dry, and apply a sealant.