The Bernese Mountain Dog is steady-tempered and easygoing.
However, his calmness and willingness to laze about doesn't mean he can be cooped up without exercise. Indeed, the Bernese loves getting out, especially in cool weather -- with his thick black coat, he doesn't do well in hot climates. Romping in the snow is a favorite form of recreation for this Alpine breed, and pulling carts and sleds is a wonderful source of exercise, especially if it involves children.
His attitude toward strangers varies from friendly to aloof, but a Bernese should remain poised and hold his ground. The most common temperament fault is excessive shyness, sometimes toward everyone, sometimes focused on one group of people, such as men with beards. A Bernese Mountain Dog puppy needs lots of socialization so that his natural caution does not become timidity.
Most Bernese Mountain Dogs are peaceful and sociable with other animals, but some Bernese males are aggressive toward other male dogs.
Responsive to obedience training in a slow, good-natured way, this sensitive breed should be handled kindly, with much praise and encouragement. However, they're not complete pushovers to train -- some can be a little bit hardheaded and dominant, especially males, and especially during adolescence.
There is great variability in size in this breed -- some individuals are medium/large and quite athletic, while others are huge and ponderous (especially males).
If you want a dog who...
Is large, heavy, and powerful
Has a thick furry coat that does well in cold climates
Is gentle-natured, polite, and non-aggressive
Is usually peaceful with other pets
Loves pulling carts and sleds and romping in cold weather
Is responsive to training in a slow, good-natured way