Freezing temperaturesand strong winds foreshadow possibly life-threatening conditions for Monday night, when caucuses begin at 7pm, per the National Weather Service Des Moines office.
Why it matters: Turnout is always the x-factor in elections, but that's particularly true at the Iowa caucuses. In some rural precincts, as few as 10 people can make a big difference.
The bottom line: It's unknown how the extreme weather could affect Donald Trump's lead because many of his supporters are in rural areas, where it'll be harder to travel to caucus sites.
And given expectations,lots of people could stay home — assuming Trump will win. But he also has some of the most enthusiastic supporters, which could play in his favor.