Metro train Crowds flooded Metro trains on Wednesday, making it the fourth-busiest day in the system’s 37-year history. Thursday is expected to be similarly busy, officials warn. (Bonnie Jo Mount/The Washington Post)

Cherry blossoms in peak bloom, a Nationals game, a Wizards game and a rally at the U.S. Capitol combined to form the perfect storm on Metrorail trains, making Wednesday the fourth busiest day in the subway system’s 37-year history.

Metro officials reported that riders took 870,171 trips between 5 a.m. and midnight, the system’s highest ridership day since April 2, 2010.

All of Metro’s top 10 ridership days have occurred in the past five years, underlining the need to expand the system’s capacity, officials added. Among the projects in the works are power upgrades and additional rail cars.

Metro warns that riders could see equally busy trains Thursday due to a near-repeat of Wednesday’s conditions. The weather is good, the cherry blossoms are still in bloom, the Nats are playing at 7:05 p.m. and the Capitals will play at 7 p.m.

Metro will provide extra Green Line trains between Mount Vernon Square and Anacostia during the evening rush hour to accommodate baseball travel, and offers the following advice to riders:

— If heading to the National Mall, consider stations other than Smithsonian, such as Arlington Cemetery, L’Enfant Plaza, Federal Center SW, Federal Triangle or Union Station.

— Purchase and load round-trip farecards or SmarTrip cards in advance.

— Don’t hold train doors open.

— Stand to the right when riding on escalators.