Snowmaking and snow storing are increasingly used as climate adaptation strategies in ski resorts all over the world, including in the Arctic. While the decrease of the number of snow cover days is slower than in the Alps, snow security is decreasing particularly at the beginning of the skiing season in October-November. As there is up to 30-times difference between minimum and optimal conditions in the energy and water consumption in snowmaking, it makes sense to optimize the timing of snowmaking to ensure that snowmaking will not turn into maladaptation. Climate services are user-friendly ways of providing relevant climate information for end-users. Our team co-designed a climate service prototype for winter tourism centers in Northern Finland in 2017-2020 by a transdisciplinary co-design process involving climate science, modelling, tourism research, and practitioners including snowmaking professionals and environmental experts from a pilot enterprise. The versatile co-design methods utilized included e.g. visual methods and workshops, and co-evaluation of the prototype. The resulting climate service prototype SnowApp provides a reliable 4-week forecast on snowmaking conditions and hence it is a decision-support tool for ski resort management. The prototype is applicable in other geographical locations, too, and for other snow dependent businesses.