1. It's not too cold, hot or wet. If the weather is too cold it can complicate excavation and prevent concrete pouring. Extremely hot weather can slow down work crews and wet weather can cause unwanted delays and turn the project into a soggy mess.

2. You have the designer and builder's undivided attention. Fall is typically a slower time of year. With the subsiding heat, fewer people think about building. For the customer, this can result in scheduling flexibility, an even more attentive designer and a less hectic building experience.

3. You're not so rushed: Who wants to be rushed when it comes to spending 30-70k on a swimming pool? By shopping for a pool now, you can make a relaxed and informed decision, and not base your thoughts on silly stipulations like 'which company can start the soonest.'  
4. Special discounts are available. Manufacturers often discount equipments, covers and accessory items in the fall and winter, therefore you may save thousands by building before the spring and summer.

5. Your yard will have a chance to heal: Pool construction is messy, make no bones about it. After final grading, grass will need time to grow. For those persons that get their pool installed earlier, their yard will look much, much nicer come June 1 compared to the person that waited to make a decision.
6. It allows you to make the most of your first summer. By building in the fall, you won't miss a single swimming day next summer. Your pool will be ready to go when the weather starts to warm up.