Attendees at presidential inaugurations can, generally, expect a speech fit for the weather.

Looking at midday temperature data for the past 52 years — stretching back to President Lyndon B. Johnson’s inaugural address after his election in 1964 — incoming presidents have tended to give shorter speeches when it’s colder outside.

The shortest speech during this time, as measured by numbers of words, came on a frigid January day in 1977. It was just above 28 degrees Fahrenheit the day President Jimmy Carter delivered that speech, which lasted less than 15 minutes.

Fast forward four years, and President Ronald Reagan was set to deliver a speech on the warmest day of those we looked at. With a 55-degree midday temperature, Reagan appeared without an overcoat and delivered a speech with nearly twice as many words as Carter’s (though it lasted only five minutes longer).

That luck caught up to Reagan, however, when he faced an Inauguration Day in 1985 that was so cold, he was forced to move his ceremony inside the Capitol. It was 7 degrees outside, and the inaugural parade was canceled.

His speech indoors was longer than any since Herbert Hoover’s.

Since then, the mercury has mercifully remained above freezing at each inauguration — except one.

President Barack Obama took his first oath of office on the next coldest day in the time frame we looked at, yet he delivered one of the longest speeches. Despite the 28-degree temperature outside, his speech was 2,395 words — about the same written length as Reagan’s first, but running two minutes shorter. Though the president donned a scarf and gloves as he walked down Pennsylvania Avenue toward the White House, he delivered the speech with only an overcoat on for warmth.

Presidents may have good reason to not speak too long in the cold. According to legend, William Henry Harrison died — just a month after taking office — from a case of pneumonia he caught delivering a lengthy speech in chilly, wet weather. Though recent evidence indicates that story may not be entirely true, no president since has even attempted to match the length of Harrison’s speech: 8,444 words.

The forecast for this inauguration suggests it could be the warmest inauguration since at least 1989, with highs projected at 50 degrees. Reports from unnamed sources indicate President-elect Donald Trump’s speech could be a short one, possibly under 20 minutes, which would buck the trend of presidents giving longer speeches on warmer days.

Still, with Trump’s history of extemporaneous, free-flowing remarks, anything could happen.