What hazard does humidity pose to ice rinks?

The presence of humidity poses a significant hazard to ice rinks primarily because it can lead to soft ice conditions. When humidity levels are high, moisture in the air can lead to the formation of a thin layer of water on the ice surface, which softens it and adversely affects its structural integrity. This soft ice can compromise the performance of skaters and increase the risk of accidents, as it may not provide the necessary friction and stability.

Additionally, higher humidity can lead to other problems such as the potential for condensation and increased maintenance challenges, but the most immediate concern is the softness of the ice itself, which can lead to unsafe conditions for users of the rink. In contrast, the other options describe effects that are either less likely or not representative of the main concerns associated with humidity levels on ice rinks. For instance, while humidity might sometimes obscure visibility due to condensation, it does not typically create a foggy surface that significantly hinders visibility. Cracking of the ice is more often linked to temperature fluctuations than humidity. Enhancing ice durability is contrary to the effects of humidity, which usually diminishes the quality of the ice rather than improving it.