Cooking the perfect boiled egg is an art. Take your eggs off the heat too soon, and you're left with runny whites; too late, and you're looking at a grey ring around the yolks. Getting that firm white and jammy yolk is not as hard as it seems, but the time it takes to cook it can change based on where you are in the world, thanks to differences in elevation, which subsequently changes the boiling point of water. Here's a list of several major cities in Canada and how long you have to cook your eggs in them to various degrees of doneness. For a more scientific approach, you can set aside a dozen eggs and take them out of the water in 1-minute increments after five minutes. That way, you can how long it takes to cook to your preferred level of doneness. 

All times below are for medium-sized eggs that are fresh out of the fridge (to mimic typical cooking practices) and placed into a pot of boiling water.

Calgary: Soft: 6:51 Medium: 7:48 Hard: 10:19

Edmonton: Soft: 6:40 Medium: 7:37 Hard: 9:57

Fort McMurray:  Soft: 6:29 Medium: 7:26 Hard: 9:37

Fredericton: Soft: 6:23 Medium: 7:20 Hard: 9:26

Halifax: Soft: 6:24 Medium: 7:21 Hard: 9:28

Hamilton: Soft: 6:52 Medium: 7:49 Hard: 10:20 

Kelowna: Soft: 6:31 Medium: 7:28 Hard: 9:41

Montreal: Soft:6:23 Medium: 7:20 Hard: 9:27

Ottawa: Soft: 6:24 Medium: 7:21 Hard: 9:28

Regina: Soft: 6:38 Medium: 7:35 Hard: 9:53

Saskatoon: Soft: 6:35 Medium: 7:32 Hard: 9:48

St. John's:  Soft: 6:24 Medium: 7:20 Hard: 9:27

Thunder Bay: Soft: 6:28 Medium: 7:24 Hard: 9:34

Toronto: Soft: 6:24 Medium: 7:21  Hard: 9:28

Vancouver:  Soft: 6:24 Medium: 7:21 Hard: 9:28

Victoria: Soft: 6:23 Medium: 7:20 Hard: 9:26

Winnipeg: Soft: 6:29 Medium: 7:25 Hard: 9:36

Quebec City:  Soft: 6:25 Medium: 7:22 Hard: 9:30