Trout like a certain tempurature range. If the water is cold in the winter or spring they will seek out slightly warmer water where they have cover but the sun still warms them. If the water is warm in summer or fall, they will look for the opposite. Of cource there are always exceptions and insect activity and water currents will also have an effect. One questions answer will always leave you with more unanswered. Think cautiously and fish often.