weather temperatures in banff in may
Key weather averages for Banff in May. 1  11. 11Â°C max day temperature. 2  6. 6 hours of sunshine per day. 3  11. 11 days with some rainfall. - 4 2. 5  16. 16 hours of daylight per day. 6  0. No heat & humidity. 7  65. 65 mm of monthly rainfall. 8  6. 6 (High) UV index.