季節とアルゴリズム変更の関係: GoogleGuy

It's true that the summer (northern hemisphere) is when traffic is lower and sometimes it's easier to roll new things into crawling/indexing/scoring. I wouldn't be at all surprised if we worked on revamping our webmaster pages, for example. [GoogleGuy's posts, WebmasterWorld]

夏（北半球）はトラフィックが減るのでクローリング／インデクシング／スコアリングに新しい仕組みを導入しやすい。