Hosting an outdoor event can be tricky- especially in January. While the weather for the 2021 inauguration of Joe Biden as the 46th president is mild, that is not always the case.
According to the National Weather Service, temperatures this time of year normally start off with a low around 28 degrees, then climb to a high around 43. Typical conditions around noon would include a temperatures of 37°F, partly cloudy sky, and a wind chill closer to 31°F thanks to a 10 mph wind.
While the D.C. area is certainly no stranger to snowfall, historically, there is only about a 10% chance that measurable snow (at least 0.1″ snow depth) at some point during the day, and only 5% odds for snow happening during a ceremony. The better chance to see snow during an inauguration would be if snow already on the ground. There is about a 1 in 6 chance for a snow depth of at least 1″ on the ground left over from a previous snowfall.
The record for the warmest January 20 was in 70° 1951. But since that wasn’t in inauguration year, the record for the warmest January 20 inauguration was set in 1981 when Ronald Regan was sworn into office under a mostly cloudy sky on a day with a high of 55 degrees. Outside of a January inauguration, the warmest day for the ceremony was on August 9, 1974 when Gerald Ford was swarm in under a partly cloudy and hazy sky as temperatures climbed to a high of 89°F.
While Regan’s first inauguration marks the warmest January ceremony, his second inauguration in 1985 was the coldest on record. That day, the morning low was -4°F and didn’t warm up much through the day. The outside temperature at noon was only 7°F and afternoon wind chill temperatures were between 10-20 degrees below zero. Because of this, the parade was canceled and the swearing in ceremony was held indoors.
The record for the most snow to fall on January 20 in D.C. was in 1961, the day of President John F. Kennedy’s inauguration. That day , they measured 8.0″ of fresh snow. The most snow ever recorded for a presidential inauguration though was on March 4, 1909 when President William H. Taft was sworn into Office. That day, 9.8 inches of fresh powder was measured and snowfall was recorded as ending at 12:20 p.m. The rest of the day was followed by clouds and a strong wind.
On January 20, 1937, Franklin D. Roosevelt was sworn in on the rainiest inauguration day, when 1.77 inches was picked up in the rain gauge. At noon, the temperature was 33 degrees, which lead to cold conditions and heavy rainfall being reported between 11 a.m. and 1 p.m. During that time, 0.69″ if rain fell, and there were reports of sleet and freezing rain earlier that morning.
During the inauguration of Joe Biden as 46th president, the weather remained mostly cloudy with scattered to broken cloud cover. While the temperature was recorded at 42 degrees, wind gusts around 25-30 mph kept the wind chill in the low to mid 30s.
More information on weather extremes and weather on past inauguration days recorded by the National Weather Service can be found at https://www.weather.gov/lwx/events_Inauguration#Extremes.