You must try night-time bathing at least once in your lifetime.
For many of years now, people have come from near and far to soak in the healing hot waters from Furnas.
Your dinner will be special too, Portuguese stew cooked in the pots dipped into the floor and will cook for several hours with the vulcanic heat.
Apart from all this, you can also admire Caldeiras das Furnas: multiple boiling water and mud springs as well as mini-geysers. They are strewn all over the town. You can also try the mineral waters or have a cup of local tea using the natural hot water.
Don't worry about the weather, worse is better, imagine you in warm water to the neck and feeling the cold drops of rain in your head or you can have a beautiful night full of stars, come to see what you gonna get.