Art fairs haven't been around long enough as a major phenomenon for us to understand their cyclicality; the past 15 years have offered a story of more or less uninterrupted growth. But all industries have a cycle, regular or irregular, and I see no reason fairs would be different.
Skates, the research and consulting unit of ARTnews, today reported that its forthcoming Art Fairs Report will show a slowdown in the growth story (though at a level that would be the envy of most developed nations). The report states that "Q1 2015 was the first quarter in 10 years of Skates art fairs tracking in which galleries and visitor participation failed to grow at a two-digit pace, on a like-for-like basis. 1,920 galleries participated in the top 12 art fairs in Q1 2015, only a 7.3% increase from the same period last year."
With 25+ fairs in Miami in December 2014, and similar growth in other markets and time periods, a slowdown isn't surprising. Even as new markets open up in Asia, new fairs continue to pig-pile on familiar destinations. Most of these fairs (and their constituent galleries and artists) are competing for mid-tier collectors who are not, in either attendance or spending terms, growing nearly as quickly as the top tier.
I have noticed anecdotally that vagaries of weather (too cold, too hot, too wet, too dry) are a popular explanation for why a fair isn't performing well, much-discussed by frustrated dealers and fair operators. Skates brings a bracing gust of empiricism to this round-the-campfire commiseration, concluding that "data over the last five years has shown no correlation to speak of between air temperature and attendance." In other words, engaged collectors will find their way to quality artworks even when it is cold. Shocker.
(All quotations above source: Skates press release 13 April 2015)