Since the primary goal is to improve irrigation efficiency, we recommend aeration during the early summer. This opens up the soil to allow water to more easily enter the soil, reducing run-off and improving irrigation effectiveness. We can't quantitatively prove it, but we believe that aeration pays for itself through water savings.
The benefits of aeration are significant but short lived lasting only 3-4 months. This is why we propose it every spring as we enter the normal peak irrigation season. This will maximize the water savings and return on your investment.
If you haven't already approved aeration for 2016, you should be receiving a proposal soon.