Washington: On what could be a record-hot day, tens of thousands of demonstrators are expected to assemble in Washington on Saturday. Their large-scale climate change protest will mark President Donald Trump's first 100 days in office, which have been punctuated by multiple rollbacks of environmental protections and Obama climate policies.

The People's Climate March, which originated with a massive demonstration in New York in September 2014, picked a symbolically striking day for its 2017 event. Temperatures could exceed 32 degrees and possibly set a record for April 29 in the District of Columbia, which would amplify the movement's message.

Marchers are sure to be further galvanised by a move taken by the Environmental Protection Agency late on Friday. The agency announced that it was beginning an overhaul of its website, which included taking down a long-standing site devoted to the science of climate change, which the agency said was "under review."

"There is no Planet B," read a sign held by Eva Gunther of Washington, D.C., as the protest assembled on the National Mall on Saturday morning.