Cherry Blossoms

I had a thought this morning about global warming. How has the date for cherry tree bloomings and the Cherry Blossom Festival in Washington, DC changed over the years? This might be a proxy for what is happening to the temperature at least in the Eastern United States. I Googled this idea and found the following chart (see: EPA Source Data for reference) of these dates over the last 94 years. As one can see here first hand, there seems little change in this indicator date except for a up-spike in 1988 and 1998 ... and, in fact, the 2014 and 2015 dates are quite late relative to much of the past:

For you Kool Aid drinkers I have also included a reference to a Boston University/Japanese study of cherry tree blossoming times around Kyoto, Japan which purports to show the opposite effect over a much longer period of time. However, it does concede that warming caused by urbanization trends may be an influence on this data. It also states that the dates for the Washington, DC festival have moved earlier by about a week ... which, as we can see above, is clearly not the case. So it might be that this study is also Chicken-Little biased (ala Mann's "hockey stick" which has been fully debunked by the actual data) ... see: Boston University PDF Reference.