Ice records at Lake George, an oligotrophic and dimictic freshwater lake in upstate New York, United States reveal that it has failed to freeze over completely 13 times since 1990. This transition from annual to intermittent ice cover is analogous to many other dimictic freshwater lakes globally. Over 60 years of meteorological observations from a nearby airport are analysed and a complicated picture emerges when considering the specific characteristics of each year. For example, Lake George froze over in 1983 and 2007 despite the air temperature having a net warming effect on the lake in the month prior to ice-in. Simple machine learning classifiers are trained using local weather data to predict the presence of complete ice coverage on Lake George and are found to perform adequately compared to observations, with one configuration having an accuracy of 91%. Using downscaled data from a coupled-climate model through to 2,100, projections with the trained classifiers suggest complete ice coverage will be a phenomenon of the past by the mid-to-late 21st Century. Furthermore, by 2080–2,100 the mean air temperature is projected to warm up to +8.0 C under Representative Concentration Pathway 8.5. These projections will be of concern to the communities and policy makers of Lake George responsible for the management of the ecological and socio-economic systems.