When will we know the results of the Midterm Elections? Possible time of the final numbers in today's race

Polls close across the United States on Tuesday, but the fight for control of Congress may continue long after the first results arrive, leaving the country waiting for a decisive answer although election night will not deliver one definitive moment when Americans learns who has won the midterms.

The first returns should follow the opening poll closures at 18:00 ET/15:00 PT, but control of Congress could remain unsettled long after voting ends as every House of Representatives seat, 35 Senate seats and 36 governorships are being contested, consuming a substantial amount of time to collect and ratify votes.

Democrats need net gains of three House seats and four Senate seats to take Congress , potentially limiting Trump 's agenda during his final two years in office and DDHQ 's latest forecast puts Democrats ' chances of winning the House at 84 percent and the Senate at 65 percent.

North Carolina , Alaska , Maine , Texas and Ohio are among the Senate contests drawing attention, but forecasts are not results, and the first indication will come as polls begin closing from 18:00 Eastern Time and continue through to as last as midnight ET in Alaska .

Those deadlines end voting, not counting. States have different rules for processing mail ballots and provisional votes, and election offices report at different speeds. Close margins can leave outstanding ballots decisive after most votes are in.

Why the final count could stretch beyond election night

Historically, Florida , Georgia , North Carolina and Texas are expected to report substantial totals relatively quickly whilst Michigan , Wisconsin and Pennsylvania may take longer, as ballot-processing rules can delay mail vote reporting.

Contests decided by narrow margins can also cause delays if recounts are issued and some states such as California may also keep some races open for days or weeks as the state accepts mail ballots postmarked by Election Day for up to seven days afterward, and those ballots require checks before they can be included in the count.

The margin and the amount of outstanding voting can matter more than the speed of reporting whilst Decision Desk HQ says it projects a winner only when it is 99.9999 percent confident but that is not official certification and it's possible they can be upset.

Election officials must complete their canvass, and experts say every state takes weeks to certify its election results meaning there is therefore no guaranteed hour for the final congressional picture.

Some winners may be projected Tuesday night, but control of either chamber could remain unclear on Wednesday if a small number of close races determine the majority.

Newly elected members of Congress are scheduled to take office at 12:00 ET/09:00 PT on January 3.

Certain special Senate election winners may be sworn in sooner, while state and local officeholders follow dates set by their respective laws.