This was an interesting Google result for "cold humidity vs hot humidity as far as a baseball travels"...
Distance Impact: A ball can travel 20 to 30 feet farther in hot, humid conditions compared to cold, dry ones
Temperature Impact: For every 10 degrees F
increase, a ball can travel approximately three feet farther
Hot/Humid (Best for distance): Higher temperatures expand air molecules, making the air thinner and less dense, allowing the ball to travel farther.
Cold/Humid (Worst for distance): Cold air is much denser, acting as a "thicker" medium that slows the ball down. Additionally, cold, humid air can make a baseball absorb moisture, making it heavier and less bouncy.