An upper level trough is a trough of low pressure which has formed in the upper levels of the atmosphere, and hence cannot be seen on surface level charts.

Upper level troughs can result in the formation of a cloudbands, which will often result in widespread rainfall near and to the east of the trough (development of showers and thunderstorms). Upper level troughs can also aid in the development of surface level features, such as frontal systems, thereby enhancing their effect. The presence of an upper level trough in a favourable position may result in the development of a cut-off low, which in turn will enhance rainfall over the affected region.