As much as I'd like to say anytime is a good time to bake macarons...truth is, don't even try making them when it's a humid day.

A humid day will not allow your piped macarons to dry properly before they go in the oven. And if the top of the piped macarons hasn't formed a crust, then your macarons won't have that beautiful "feet". Worse still, the top will be cracked. 

So I always check weather forecast when planning when to bake! 

Happy Baking!