Thought it might be of interest to some - Sensirion Humidity & Temperature sensors on an Xplained-Pro Extension Board:
https://www.sensirion.com/en/abo...
Note that it is a 3rd-party product - not an Atmel/Microchip product.
EDIT:
They say, "for Atmel’s SAMD20 Xplained Pro Board", but the headers should be standard across all Xplained-Pro Boards - so it shouldn't be limited to the SAMD20 at all.