On 25 July 2016, helicopter-based measurements were made of the volcanic gases emitted from Mount Cleveland, Alaska, USA. An upward-looking differential optical absorption spectroscopy (DOAS) system was used to measure incident scattered solar ultraviolet radiation while traversing beneath the plume on multiple occasions. These data were used to derive volcanic SO2 emission rates. Additionally, a Multicomponent Gas Analyzer System (Multi-GAS) was used to make measurements of trace gas concentrations while on a dedicated measurement flight passing through the volcanic plume. Radiance spectra and gas compositions were both recorded at 1 second time resolution. Each spectrum and gas measurement was stamped with the GPS time and location. Each spectrum was saved in a separate ASCII file which includes 2048 radiances measured in the 285 - 430 nm spectral region and metadata associated with each acquisition. The Multi-GAS measurements are saved in a spreadsheet in the *.csv format. In addition to the helicopter-based measurements, ultraviolet imagery of the volcanic plume emitting from Mount Cleveland was collected on 24 July between 18:00 and 19:30 UTC using a ground-based SO2 camera instrument located 3.4 km east of the volcano's summit. This imagery was used to quantify the absorption of light by SO2 in the volcano's plume, resulting in a time series of SO2 emission rates. For more information see the associated interpretive publication: Werner C., Rasmussen D.J., Plank T., Kelly P.J., Kern C., Lopez T., Gliss J., Power J., Roman D.C., Izbekov P., Lyons J. (2020). Linking subsurface to surface using gas emission and melt inclusion data at Mount Cleveland volcano, Alaska. Geochemistry, Geophysics, Geosystems. https://doi.org/10.1029/2019GC008882