Image source, Getty Images

This is a very quick projection. It provides a strong indication of Donald Trump's dominance.

Votes are still to be counted, with only 11 of Iowa's 99 counties so far reporting results.

CBS News entrance polls showed Trump receiving strong support from white evangelicals and very conservative voters, key voting blocs who were not convinced of his credentials back in 2016.

The former president seems to have received strong support tonight among men and women, and among older and younger voters, improving on his 2016 performance with all four groups.

As we mentioned earlier, most caucusgoers also dismissed his legal woes. Several said immigration was the top issue driving their vote.

Meanwhile, Nikki Haley and Ron DeSantis appear to still be battling for second place.

The BBC’s US partner CBS News estimates that Donald Trump will win at least 16 delegates in Iowa

Iowa has 40 Republican delegates up for grabs that are awarded proportionately.

Donald Trump is projected to win the Iowa Republican caucuses, according to CBS News.

About two-thirds of Iowa caucusgoers do not believe Joe Biden legitimately won the 2020 election, with that number going up to nine in 10 among those voting for Trump tonight.

Early interviews with voters in Iowa Republican caucus locations suggest Donald Trump's 'Make America Great Again' movement is well-represented here.

Polling backs that up. Roughly half of caucus goers in CBS entrance polling said they consider themselves part of the "Maga movement".

The former president has just appeared at Clive, a small city just to the west of Des Moines.

He's speaking to locals before they start to vote.

Trump will be heading back to Des Moines for his watch party later tonight.

Immigration was the top issue animating Iowa Republicans as they arrived at caucus locations across the state, according to CBS News' entrance polling.

Economic concerns follow closely behind.

The most important quality in a candidate for these voters is someone who shares their values, followed by someone who fights for people like them.

Most voters in Iowa are dismissing the legal woes of frontrunner Donald Trump. Six in 10 voters say that, if Trump is convicted of a crime, he will still be fit to be president.

Holly Honderich
Reporting from Des Moines

Just minutes before the start of the caucus at Grant Ragan Elementary school in Waukee, Iowa - a suburban town on the outskirts of Des Moines - several voters told me they're going to back Nikki Haley.

This makes sense - she is most popular with the more moderate Republican voters who live in areas like this.

Her supporters include Chris Cook and his daughter Emma, who is voting for the first time.

Chris says he likes that Haley seems more inclusive and more willing to work to work with Democrats than the other candidates.

But is his party ready to move on from Trump? “No,” he says.

Bernd Debusmann Jr
Reporting from Des Moines, Iowa

In a surprise twist, I just ran into a group of extremely enthusiastic British "political tourists" here to watch the caucus take place.

Among them is Londoner Caroline Sumnall. "It's an amazing place to watch," she tells me.

"We've seen Trump, Haley and Vivek as well." "It's fascinating and Iowans are completely lovely," she added.

"They're really welcoming and will talk about their opinions really openly."

The group is unanimous in believing Trump will be the far and away winner, but is split on their second place prediction.

"I think it depends on the weather," she said. "But we've heard that people are more passionate about DeSantis."

They plan to attend DeSantis' official results watch party later.

It appears Trump may already have the early advantage in this Iowa race.

CBS News, the BBC's US partner, says that the race "leans Trump" based on its entrance poll of Iowa voters as they entered the state's numerous caucus events.

These are the early moments, so more information is to come. Stay tuned.

The Iowa caucuses are set to start in meeting rooms, high school gymnasiums and other caucus sites across the state.

Caucusgoers will hear from representatives for the candidates before they vote.

Stick with us as we bring you the latest.

Gary O'Donoghue
Reporting from Des Moines

The buzz is beginning to grow at Van Meter High School in Dallas County in western Des Moines.

The school’s basketball court is strewn with tables where the caucus votes will be counted and the bleachers will be filled with Republican voters.

Two precincts are meeting here - due to the huge growth in population in this area since the last competitive Republican primary in 2016.

Donald Trump squeaked in second place then - but all eyes will be on how far ahead of the field he is here tonight.

David Young, a Republican who serves in the Iowa House of Representatives, says his state takes its first-in-the-nation job very seriously.

"We don’t just pick corn here, we pick presidents."

Nomia Iqbal
Reporting from Des Moines, Iowa

If you’re wondering what a caucus looks like, we’re at one! A cafeteria in a classic local high school. As well as the US and Iowa flags - there are also ones from all around the world hanging from the ceiling. Trophy cabinets are built into the walls and a big mural of high school sports.

There are some young people inside ready to vote - some wearing Trump caps. Everyone has to be in by 7pm local time. However officials here have extended it by 15 minutes due to the bad weather.

Couples, families, are trickling in all wrapped up from the cold. We spot one man with a Nikki Haley shirt and sign. One lady makes her way past us, moving slowly with a walking stick she says:

“They didn’t think the old folk would come out did they. But we did! It’s important!”

This venue is hosting three precincts. The precinct chairman Neil McDonald showed us the important paper work. First up the ballot - a small unremarkable piece of paper where voters write the name of the candidate they prefer. And then an orange sheet with all the candidates’ names. He will count the votes, tally them up and then announce the results for this precinct a few hours later.

Holly Honderich
Reporting from Des Moines

I’m at a caucus site in Waukee, a suburb of Des Moines.

Precinct chair Terry Rich is giving his introduction speech to a hundred-odd voters preparing to make their decision.

It’s bone-chillingly cold outside, but Rich tells me the rumours of low turnout have been greatly exaggerated.

“I don’t think the weather is going to make a difference,” he says. “It will be a good turnout, it’s going to be fun.”

Rich has decided to cast his vote for Nikki Haley. He says the Republican Party needs a fresh start and a leader that can be a president for the entire country.

Plus, he loves that Republicans could beat the Democrats in making history.

“Ten years ago, I could never have guessed that I’d vote for the first female president of the United States, and that it would be a Republican.”

Bernd Debusmann Jr
Reporting from Des Moines, Iowa

This may be the Iowa caucus - but people have come from far and wide to participate.

I just ran into Glenn Jacobs - a former WWE wrestler and current mayor of Knox County, Tennessee. Formerly known as "Kane" in the wrestling world, he's an imposing figure standing at an extremely muscular 7ft (2.14m).

He's here to speak on behalf of Donald Trump, a man he has supported since he left the wrestling ring for the political stage.

Jacobs says he felt compelled to come help drum up support for Trump because the "country is headed in the wrong direction" - citing a litany of issues ranging from the border to the "weaponisation" of the Justice Department and foreign entanglements in the Middle East.

He expects that tonight will be a "blowout" for the former President.

"I think he will have an overwhelming victory," he said. "Trump supporters are very loyal, and very energetic."

Bernd Debusmann Jr
Reporting from Des Moines, Iowa

I've just arrived at Roosevelt High School in Des Moines, where several precincts will be caucusing tonight.

A slow and steady trickle of people have started to arrive.

Among them is Hallie Still-Caris, an ardent supporter of Nikki Haley. She'll be speaking on her behalf shortly.

The main reason, she said, is that many view Haley as "electable" in a general election against Joe Biden - a quality she thinks Ron DeSantis and Donald Trump lack.

"That's the primary reason for my willingness to get involved," she said

"I look at the other Republican candidates and President Biden, and I think she's electable. That's what we need - less drama and less chaos."

"I'm very confident Nikki will come in a strong second place," she added.

This venue can easily accommodate several hundred caucus goers across a large auditorium and cafeteria. But so far, only a handful have arrived.

"We hope a lot of people come," a volunteer told me.

Sarah Smith
North America editor, reporting from Des Moines, Iowa

This is the scene at the venue where Donald Trump will speak later. Fresh popcorn has just been laid out, but there's no sign of any guests.

There isn’t room for more than a couple of hundred supporters. Nothing like the huge crowds he often draws to his rallies and events.

But there is no shortage of reporters and TV crews jostling for space on the press riser

The Iowa caucus may be the first contest in the Republican presidential primary, but its results are not "a litmus test for how the rest of the primary will go", a Republican political strategist tells BBC News.

"Look back to 2016," says Rina Shah. "The Trump campaign hit its first speed bump in these caucuses."

In the 2016 caucus, Iowa Republicans backed Texas Senator Ted Cruz over Donald Trump, though Trump eventually went on to win the nomination convincingly.

"Tonight could go one way or another," according to Shah, but the frigid weather may have turned things in Trump's favour, as it has now become a case of whose supporters are most enthusiastic.

But Shah contends that Trump "has to dominate [over Nikki Haley and Ron DeSantis], not just be the frontrunner" tonight.

She notes that none of the three major candidates have as much stake in tonight's result as DeSantis, who has visited all 99 of the state's counties, secured the endorsements of Governor Kim Reynolds and influential evangelical leader Bob Vander Plaats.

Mike Wendling
Reporting from Davenport

Voters are starting to file into Central High School, perched on a hill here in the eastern Iowa city of Davenport.

The cold weather clearly hasn’t deterred the die-hards who are busy finding their local precinct meetings, which are spread out around the school.

In the auditorium, I meet Linda Lanman. She’s tells me she’s been to many caucuses in the past and this year she’s turning out for Ron DeSantis.

“I like what he’s done in Florida,” she tells me.

“And with Trump, I just feel like there’s trouble coming down the line,” such as the former president’s legal troubles.

But those troubles don’t deter Kiowa Gipson, who’s firmly in the Trump camp.

“I don’t agree with everything he stands for, but he’s done a lot of good for this country,” he says.

The real battle in Iowa could be for second placepublished at 23:53 Greenwich Mean Time 15 January

23:53 GMT 15 January

Anthony Zurcher
BBC North America correspondent, reporting from Des Moines, Iowa

If Donald Trump’s dominating poll position proves to be an accurate reflection of Iowa Republican voter mood, the real battle in the state is for second place.

Wednesday’s acrimonious two-person debate between Florida Governor Ron DeSantis and former UN Ambassador Nikki Haley put the high stakes here in stark relief.

If one of these two opens some daylight between the other in the final Iowa results, it could elevate that candidate as the top alternative to Trump in the contests to come.

A close finish does neither any good, essentially boosting the divide-and-conquer strategy that helped Trump win the nomination in 2016 and would give him an easier path to victory this time around.

Even if one candidate banks a comfortable runner-up finish in Iowa, there’s no guarantee that it will translate into future success and an opportunity to catch the former president.

A slim chance is better than no chance at all, however.

Brandon Livesay
Reporting from Des Moines, Iowa

Image source, Supplied

People have just started to show up at the caucus sites dotted across the state of Iowa. And while polls show Donald Trump is the frontrunner, some Republicans will wait until they are inside a caucus and hear speeches from campaign surrogates before they make up their minds.

Mary Weston, 23, lives in the east side of the state in Linn County. It's an area she describes as "pretty blue, maybe borderline purple".

Weston tells me she has narrowed her vote down to former president Donald Trump, Nikki Haley and Ron DeSantis, saying she wants to caucus for the candidate that has the best "prospect of electability against Joe Biden".

"I hate using the word longshot… they have all worked. They are all trudging through the snow," she tells me.

And whoever wins in Iowa, Weston says she will support them "1000%." She also says it won't be easy for whichever candidate wins the overall Republican nomination later this year.

"I think it's going to take a bit more effort to sway the moderates and independents and Libertarians. I think they have to work hard to do that… That will be the only way Republicans can win (the 2024 election)."