As for the online weather forecasts for Kibune (貴船), for a week in advance.
http://weather.yahoo.co.jp/weather/j...3/6011112.html
Post code (〒601-1112) means the adress of 京都市左京区鞍馬貴船町. (You are from Hong Kong, so I suppose you can catch the meanings of 漢字 on it's page)
Needless to say, forecast varies from hour to hour. Please check it out at your accommodation after your arrival.
Sorry for my poor English.