Fungal disease infection risk is strongly dependent on the climatic conditions and on the plant microclimate. Leaf Wetness Duration (LWD), i.e. the time that free water remains on leaves in relation to rain or dew events is for many fungal species the significant parameter linking the epidemic risk to environment humidity. However modeling LWD has always been a complicated task, mainly because of the specific variables needed such as solar radiation and light and water distribution in the canopy, requiring local measurements. Our recent works led to the development of a framework improving the physical modeling of leaf wetness duration without on-site measurements – thanks to high resolution weather nowcasts and forecasts – and a minimum of empirical values, in order to make the model portable to different locations and pathosystems. The model takes into account the tree architecture and leaves physical and phonological properties.The model has been validated for apple McIntosh cultivar using past local weather variables measured in 2014 St-Bruno-de-Montarville, Quebec, Canada. Hourly simulation during the whole year produced a leaf wetness duration RMSE of 26 minutes.