The Boston Marathon debuted back in 1897, and since then, the oldest marathon in the country has gained a reputation not only for its historic course, but for the weather which has affected the race in monumental ways.
Run on Patriot’s Day, the race lands squarely in the middle of New England’s most fickle season. April is a month when spring warmth can quickly give way to either winter’s last gasp or summer’s brutal heat. Temperatures can be in the 50s in the morning, and the 80s by the afternoon this time of the year.
What makes the Boston Marathon unique is this very unpredictability. Unlike fall marathons, where weather patterns are more stable, Boston demands adaptability. Runners must prepare for a wide range of possibilities: layering for cold, hydrating for heat, and bracing for wind or rain.
Indeed, the marathon has seen it all when it comes to weather. Over the decades, runners have experienced near-perfect racing weather, with temperatures in the 40s to low 50s, light winds, and overcast skies. Throw in a nice tailwind from the west and you have conditions for record-breaking times.
The marathon in 2011 was one such day, with a Hopkinton temperature 46 degrees, a Boston temperature of 55 and a strong tail wind. This resulted in the fastest marathon on record and many sitting there personal best. The 2011 record of 2:03:02 set by Geoffrey Mutai of Kenya still stands as the course record.
The following year, a similar tailwind occurred, but instead of propelling runners, it propelled temperatures. Readings in the 2012 race started in the 60s and ended up in the mid- to upper-80s. It remains one of the hottest Boston Marathons on record, and organizers urged runners to slow down or defer the race. Medical tents filled quickly as heat exhaustion and dehydration became major concerns. For many, simply finishing became the goal rather than achieving a personal best.
It was three-and-a half decades earlier, in 1976, that the so-called “Run for the Hoses” took place, with many watchers spraying the runners with water as the first part of the course saw searing heat near 90 degrees. It did cool off as runners approached Boston, with a welcome seabreeze that year. But with a warming climate, it becomes more and more likely that future marathons may have to contend more with heat than cold and snow.
Averages give us some idea of what to expect each year. Most years, the temperature is above 55 degrees, and the chance of significant precipitation is fairly low, with only about 20% of years seeing significant measurable rainfall.
But there are years when precipitation defines the day. Cold, driving rain can be as challenging as heat. Runners endured cold temperatures with a few snow showers in 1961 and 1967. There’s also mention of snow in 1908 and 1925, although nothing significant.
The fact that Boston’s course is point-to-point makes it particularly vulnerable to wind direction. A strong tailwind can propel runners to faster times — as in that 2011 race — but a strong easterly headwind can turn the race into a grueling battle, especially headed on Heartbreak Hill.
In terms of both rain and wind, the 2018 race stands out for me as one of the most miserable in history, with temperatures in the 30s and 40s accompanied by a windswept rain creating a stiff headwind. As a forecaster for that race, hypothermia was a real concern. Elite runners struggled alongside amateurs. Desiree Linden’s victory that year became iconic not just for being the first American woman to win the event in 33 years, but for the sheer toughness required to endure the conditions.
Then in 2010, there was one of the most unusual natural phenomena to impact the course: The eruption of the Eyjafjallajökull volcano in Iceland, which disrupted travel from Europe and caused hundreds to miss the race.
In many ways, the weather has become part of the Boston Marathon’s identity. It adds an element of drama, and works to help level the playing field, causing even the most elite athletes to contend with the same forces as every other runner. Whether it’s a perfect spring day or a test of endurance against the elements, the Boston Marathon continues to prove that here in New England, weather is always part of the story.
