Out in the enthusiastic crowd, the frosty, foggy weather that lingered throughout Summerfest's opening day certainly didn't make things feel like a summer celebration of music. Luckily, even if the weather didn't seem fitting of the opening day of Summerfest, from its first growling number, the beloved punky British rock band Arctic Monkeys' solid 90-minute show proved to be a more than worthy way to crack open this year's festival.