Disadvantages of Underground Transmission over Overhead Transmission. 1  Underground transmission line cable is costlier than overhead transmission. 2  The maintenance cost of underground cables is higher than over head transmission. 3  Capital cost of Overhead Transmission lines are cheaper than underground transmission line.
the average annual rainfall for Canada is 60.33 cm. That is alot! Any average is going to be a meaningless because Canada covers over 9 million sq/kms, extending from the Nor â¦ th Pole to below the 49th parallel and both east and west coasts of North America.
Key weather averages for Canada in May. 1  18. 18Â°C max day temperature. 2  7. 7 hours of sunshine per day. 3  12. 12 days with some rainfall. 4  7. 7Â°C min night temperature. 5  15. 15 hours of daylight per day. 6  0. No heat & humidity. 7  73. 73 mm of monthly rainfall. 8  6. 6 (High) UV index.