Concerning the weather, you can also check annual charts for the area. Looking at Rome, the average precipitation from Jan. to April is under under 25mm per month, a bit of a spike in May, then it drops off dramatically until September.
http://www.holiday-weather.com/rome/averages/
Also considering the mountainous terrain around Ficulle, any rain that did fall would not sit on the surface but run off, assuming road network is not all level.
http://www.maplandia.com/italy/umbria/terni/ficulle/
regards,
Jack