many fungi can infect cherries, here silver leaf occurs in the winter. Some info from a UK site.
Silver leaf (Chondrostereum purpureum) is a fungal disease which attacks a wide range of deciduous trees and shrubs, however Prunus species are particularly susceptible to it. The fruiting bodies of the fungus produce spores which are carried by wind and infect trees and shrubs through wounds, mainly caused by pruning.
The fungus produces most of its infectious spores in autumn and winter where drizzly, rainy, foggy or humid days with no wind or sun provide the perfect conditions for spore release and infection. By pruning susceptible species at this time, you will open up wounds which will be slower to heal as the tree is in its dormant stage and will provide an entry point for infection.
Once infected, the characteristic symptom of silver leaf disease is a silvery sheen on the foliage. This is caused by the fungal toxins in the sap stream being transported to the leaves and causing the leaf tissue to separate, giving the leaf a silvery appearance. Symptoms can develop throughout the whole tree or on just a few branches depending on the point of infection, however, once branches die, fruiting bodies grow on the dead wood and the cycle starts again. When branches are cut across, an irregular, dark stain may also be observed in the centre.