The Galilee is prettiest in the spring months of March and April when it is covered with wild flowers, and its hills are draped in green. Summer can be torrid. Avoid the Sea of Galilee during Passover (March-April) and the High Holidays and Sukkot (September-October). Although the weather is great at these times, half the country vacations here; rates soar.
Some hotels charge high-season rates during July and August; this is also true the week of Christmas. Weekends in general (Thursday night through Saturday night) are more crowded; some hotels hike rates substantially.