The Cherry Blossoms at the Tidal Basin one day before peak bloom, March 19, 2012. (Kevin Ambrose)

In the NPS’s 92-year record dating back to 1921, the only years with earlier bloom dates were 1990 (March 15) and 2000 (March 17) . Three other years in the record matched this year’s peak bloom date of March 20: 1921, 1927, and 1945.

This year’s relatively early bloom fits a longer term pattern of earlier and earlier bloom dates. The average bloom date has shifted about 5 days - from around April 4 to the tail end of March - in the last 90 years . D.C.’s average March temperature, a key predictor of bloom dates, has warmed by about 2.2 degrees in that span.

Link: D.C.’s cherry blossoms have shifted 5 days earlier: what about global warming and the future?

March 2012 in D.C. is on pace to be the warmest on record, with the average temperature running more than 11 degrees above normal.

As far back as February, long-term weather forecasts suggested a high likelihood of very warm temperatures in March.

The Capital Weather Gang used this information (in early March) to issue its first cherry blossom bloom date prediction of March 18-22, which verified perfectly.

Capital Weather Gang readers also correctly predicted an early bloom. 60 percent of readers polled indicated the bloom would occur between March 17-23.

For its part, the NPS initially forecast a peak bloom of March 24-31 on March 1 which it refined to March 24-28 and then revised to March 20-24 (on March 14) when it became apparent the unusually warm weather would materialize.

With the blossoms having peaked, how much longer will they flourish? The bloom period can extend up to 7 to 10 days after peak bloom. However, with heavy rain in the forecast this weekend, the best remaining days of viewing may be today and Friday.