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.
Weather in Canada in September. The average maximum daytime temperature in Canada in September is a comfortable 20Â°C (68Â°F). There are usually 6 hours of bright sunshine each day, which represents 46% of the 12 hours of daylight. Expect 80mm (3.1 inches) of rainfall across the whole of September with 12 days with some rain falling. Maximum UV levels will be moderate (5 UV index) at midday when the skies are clear. The average night-time temperature is usually a cool 9Â°C (48Â°F). The weather in Canada in September is represented by Ottawa.