Another way of looking at seasonal weight
The data are incomplete, so the apparent weight gain starting in July is mostly an artifact of not having much late summer data.
This shows that in many years, I put on around 5 kg (~10 lb) over the holidays, then work it off in the spring. In 2010, I started working that weight off unusually late, in April, and I paid for it. This year, I had more physical activity earlier in the year than usual, and I made an effort to watch what I ate. The results show above. My scale's crude estimate of BFI is 13%.