 The month with the most days of precipitation is May, with an average of 13.5, but with only of rain or snow.The driest month of the year is February with an average of of precipitation over 11.2 days.In Sissach about 2,156 (40.5%) have completed non-mandatory upper secondary education, and 762 (14.3%) have completed additional higher education (either university or a "Fachhochschule").