Whether we can go on the trip depends on the weather.
Literal
Trip [to-に] can-go [whether-かどうか] [topic-は] weather dependent is.
~かどうか (whether or not) creates a yes/no embedded question. ~次第です (depends on) is a decisive pattern: 天候次第 = 'weather-dependent.' 次第 directly attaches to a noun meaning 'it depends entirely on X.'