Citing cooler than forecast temperatures this week, the National Park Service last evening (March 15) revised their peak bloom forecast again. They now expect the start of the peak bloom period to be March 23-24. And they're putting an emphasis on this being the beginning of the period.
For photos of how the trees were looking as of yesterday, take a look at the March 15 Cherry Blossom Watch update.
— National Mall NPS (@NationalMallNPS) March 15, 2016
They also judged that 70 percent of the trees had reached the "extension of florets" stage on March 15.