Donald Trump declared that he isn't "going to let some rain stop” America's 250th birthday celebration as attendees at the National Mall were asked to evacuate.

Washington's July 4 celebration attendees this year will have to contend with stepped-up security, possible thunderstorms and temperatures that could top 100F.

The United States of America is marking its 250th anniversary with celebrations President Donald Trump has billed as “the most spectacular birthday party the world has ever seen”.…