Wrigley is in close proximity to Lake Michigan, which can greatly effect wind patterns. Wind in more apt to blow harder during daylight hours as well, which comes into play with the Cubs playing more day games.
When it comes to Cub home games, books will release totals later than any other game, they do this for two reasons, one, to analyze all the weather conditions, and two, to make sure sharps don't beat them to the total.
Zinoco - Wrigley is located right by Lake Michigan. The wind blows in more than out (winds off the lake). The stadium is also short. Not uncommon for balls to rise about the top. If you get strong winds, it will push the ball hard. No other stadium has this effect. Wrigley also has little foul territory, and the shortest power alleys.