SIOUX CITY, Iowa — Twelve months of campaigning in Siouxland prior to the Iowa caucuses drew to a close Sunday, when the heavyweights who spent the most time at the top of polls in 2015 had events at nearly the same time in downtown Sioux City.

Roughly 24 hours before the Monday caucuses, a combined 2,200 people turned out Sunday to see Democrat Hillary Clinton at the Sioux City Convention Center and Republican Donald Trump at the Orpheum Theatre. The two events overlapped by a few minutes, as Clinton was wrapping up her 40 minutes of remarks as Trump began just before 6:30 p.m.

The venues were four blocks apart, and people buzzed with anticipation as Trump (with 1,700 people) and Clinton (500 people) made final appeals for Iowans to caucus for them.

"It is one of the bigger (Iowa) cities to be in, so they can catch people," said Kim Culver, of Vermillion, S.D.

The Secret Service also took help from local law enforcement, but no streets were closed.

The Clinton and Trump events ended a three-day spree of 17 combined campaign stops by 10 Republican and Democratic candidates.

The caucuses begin at 7 p.m. in hundreds of precinct sites in Siouxland. People have to be registered as either Republicans or Democrats to take part. Party officials have encouraged people to show up to precinct spots, which are overwhelmingly schools this year, at least a half hour before the start time.

Caucus organizers are hoping the snow blast that is headed for Siouxland will hold off until after the evening caucuses. The National Weather Service has set a blizzard watch for all Northwest Iowa counties beginning late Monday evening, given the possibility of 4 to 10 inches of snow, combined with heavy winds. The forecast shows snow could begin by late afternoon Monday, but the heaviest snow is predicted for Tuesday.