Two new partners, Our Dynamic Earth and the Clipperton Project, have joined organisers Geopark Shetland, the RSPB and Scottish Natural Heritage.
The Our Dynamic Earth team from Edinburgh will explore moving plates, volcanoes and earthquakes at the Shetland Museum and Archives.
The Clipperton Project will be running a series of unique expeditions of discovery aboard a floating laboratory at various locations around the isles.
Guided walks and the ever popular open days at Noss and Sumburgh Head are included in the programme, in addition to more creative ways of engaging with the natural world such as parkour sessions at the Sletts and snorkeling tours at Leebitton.
Programme coordinator Robina Barton, of Shetland Amenity Trust, said: "It's wonderful to work with people who are experts in their field and have this ability to communicate their knowledge and enthusiasm in fun and interesting ways.
"We already know that the festival brings visitors to the islands, and now it is providing a means by which local residents can access and enjoy activities with organisations such as Our Dynamic Earth and the Clipperton Project.
"In spite of very real economic challenges, we're working to ensure this festival goes from strength to strength."