。
The ice melted in the sun.
Literal
Ice [topic-は] sunny-area [in-で] melted [completely-てしまった].
日なたで溶けてしまった — 日なた means 'sunny spot.' てしまった marks the completion, with a sense of 'ended up melting' (not necessarily regret here, just finality).
。
The ice melted in the sun.