The Mill Race links upstream Lough Feeagh with Downstream Lough Furnace. The channel is short (200 metres) and shallow (<1 metre generally) and water temperatures measured here are very close to those measured on the surface waters of Lough Feeagh. This record has therefore, historically been used as a proxy for Lough Feeagh surface water temperature. Between 1960-2004, a Negretti paper chart recorder was used, and data were extracted for midnight each day. The chart recorder was checked sporadically against a mercury thermometer. From 2004 to 2009, a StowAway TidbiT temperature data logger from Onset (TBI32-05+37) was used (https://www.onsetcomp.com/products/data-loggers/tbi32-0537 ), and data extracted for time step nearest midnight. Between 2010 and 2017, temperature was recorded using an Orpheus mini water level recorder and data extracted for time step before midnight. Suggested Citation: Dillane, Mary; de Eyto, Elvira; Cooney, Joseph; Hughes, Pat; Murphy, Michael; Nixon, Pat; Sweeney, David; Poole, Russell. (2018) Midnight surface water temperatures from the Mill Race, Furnace, Newport, Co. Mayo. Marine Institute, Ireland. doi:10/cvft.