Ask HN: Does season affect Y Combinator results?

The summer versus winter batches makes for an interesting experiment in seasonal effects.

I would think that longer days mean more distractions, but perhaps also more energy. Personally I find that I'm somewhat more productive when I have longer days.

Does anyone have hard data on the differences (or an idea to easily test it)? Other than season, are there other differences between the summer and winter batches that would influence the data?