Question

Are these complete sentences, or is one of them a fragment?

Answer 1

Answer:

one of them is a fragment, it's the latter sentence.

Explanation:

it seems that the second sentence has gotten it backwards.

the beginning part "especially when the wind picked up" is what makes it a fragment.

doesn't it make better sense if it were written in this way instead?

"the conditions were perfect for flying our kite, especially when the wind picked up."