The Weather Weaver by Tamsin Mori

What if you could befriend a cloud? What weather would you choose? What if the weather matched itself to your mood, whether you wanted it to, or not?11-year-old Stella has returned home to Shetland to spend the summer with her Grandpa, but it's nothing like she remembers. Grandpa is lost in his grief for Gran. Stella feels trapped, until she encounters an old woman, Tamar, who can spin rainbows and call hurricanes. With the help of Nimbus, a feisty young storm cloud, Stella begins to learn the craft of weather weaving.

But when her cloud brain-fogs Grandpa and The Haken (a sea witch) starts to close in, she realises that magic comes with big responsibilities.

I loved this unusual, pacey adventure!