Its about 50% humidity and 103 outside. Should I make the littke characters that are going to be sitting on the cake out of fondant or gumpaste? I need to start these guys quick!
TIA!!

Gumpaste is going to dry harder.

I'm in Dallas and I'm doing all my figure work in gumpaste right now. Just delivered a Barney and Baby Bop cake a few weeks ago in 105 degree heat and the figures held up really well. One thing to consider is supporting the figures if they are at all heavy. The Barney was on a 2-layer, 6-inch cake. While I was delivering, the figure put enough weight on the buttercream filling to cause the top layer to smoosh down a bit and Barney was leaning when I got to the venue. Lesson learned--if the topper is the least bit weighty, go ahead and use some tea straws/dowels/whatever just to be safe. Sorry to drone on, but if it helps anyone else...

gumpaste, definitely!

Thanks everyone! Gumpaste it is

with that much humidity you have to go the GP route, fondant will dry in a million years!

You should be using gumpaste in the first place because it keeps it's shape. I prefer using 50/50.