The National Park Service updated their Peak Cherry Blossom forecast on Wednesday due to an extreme cold snap expected across Washington, D.C. for the weekend.
The peak bloom period was originally expected to occur during March 14-17, but now according to a Park Service Press Release:
"Using recent temperature data, the current progression of the blooming phases, and the weather forecast for the next seven days, the National Park Service is forecasting that March 19-22 will be the start of the peak bloom period for the cherry blossoms"
Even with the delay, the blooms have reached stage 3 of the 6 bloom stages. The National Cherry Blossom Festival will continue to start on it's adjusted start date of March 15th.