The east-west coordinate that measures how far a location is from the Prime Meridian, expressed in degrees from -180 to +180.
Longitude lines (meridians) run from the North Pole to the South Pole. The Prime Meridian (0 degrees) passes through Greenwich, England. Locations west of the Prime Meridian have negative longitude values; locations east have positive values.
In Canada, all longitudes are negative (west of the Prime Meridian), ranging from approximately -52 degrees (Newfoundland) to -141 degrees (Yukon/Alaska border).