Declining Arctic sea ice thickness and extent over the past several decades has resulted in extensive regions of thin ice vulnerable to melting. We use the ERA-5 reanalysis along with a fully coupled atmosphere-ocean-ice model (Navy ESPC) to explore the role of Arctic cyclones in summertime sea-ice change. The ERA-5 reanalysis is used to statistically analyze how surface energy fluxes and wind forcing from Arctic cyclones in the marginal ice zone between May and August (1999-2018) influence sea-ice extent on 1-10 day timescales. In May and June, cyclones decelerate the local seasonal loss of sea-ice extent due to a reduction in the incoming solar radiation. In late summer, cyclones no longer decelerate the seasonal loss of sea-ice extent, despite still reducing the net surface energy flux. Surface wind forcing across the ice edge explains only a small fraction of the short-term changes in local sea-ice extent, which suggests other processes not accounted for in this analysis, such as bottom melt, become important later in the melt season. In order to gain a more detailed understanding of how cyclones affect sea ice we then utilize the coupled Navy ESPC to examine the intense “Great Arctic Cyclone” of August 2012. Two mechanisms of cyclone-induced melting are identified: turbulent mixing of a warm layer located at 15- to 35-m depth increases bottom melting and warm air advection by the strong surface winds increases surface melting. The sea ice melt rate is substantially enhanced by the cyclone, however this effect is confined to a relatively small region and only lasts for a few days. Lastly, we note that despite the marked trend in the reduction of sea ice extent over the past several decades, reanalysis indicates little trend in the Arctic storminess as diagnosed by kinetic energy as a proxy for Arctic cyclones.