Most brown trout populations will spawn between September and December, as their eggs and juveniles need plenty of cold, oxygenated water to survive. Their optimal spawning temperature is between 43 and 53F (5 and 12C).
Brown trout (Salmo trutta) can reach a weight of about 45lb and a length of 45 inches. Their average size is between 1 and 5lb and 10 and 20 inches.
While the average size of rainbow trout is 15 to 25 inches and 1 to 5lb, this trout species can reach a maximum size of around 40 inches and 35-40lb. Some genetically altered stocks can even produce fish that weigh close to 50lb.
While the average size of steelhead is 20 to 30 inches and 4 to 10lb, this trout species can reach a maximum length of around 45 inches and a maximum weight of about 40lb.
While the average lake trout weighs somewhere between 5 and 15lb and measures a length of about 20 to 30 inches, huge specimens can reach a maximum size of 60 to 80lb and 40-50 inches, and the giant lakers of Northern Canada can be even larger than that.
Lake trout typically spawn during the fall, from September in the northern parts of Canada through November in the upper regions of the United States. Most fish spawn during the night in shallow lake areas in depths of 3 to 10 feet.