By Robert Johnson
April 14, 2019
After last year’s Boston Marathon was run in horrendous conditions which resulted in the slowest men’s winning time since 1976 and slowest women’s winning time since 1978, I can understand why many have been fearing history would repeat itself for tomorrow’s 2019 edition ever since it became apparent about a week ago that rain would be in the area.
Well, I’ve got good news to report. There is no need to bail on Boston as some were contemplating on the message board last week – MB: Anyone else considering bailing on Boston?
The weather is going to be decent and might even be conducive to running a PR. This afternoon, I got on my new favorite app – Dark Sky (which I only learned about last week) – and pulled up the forecast for the start (Hopkinton), mid-point (Wellesley), and finish (Copley Square) for tomorrow’s race. I then forwarded screenshots of the forecast to LetsRun.com’s weather/stat guru – John Kellogg.
In case you aren’t a regular long time visitor of LetsRun.com, Mr. Kellogg is the lone man in the world who before the race in 2011 said it wouldn’t surprise him to see the world’s fastest marathon ever run in Boston if the runners ran hard from that gun. And that’s exactly what happened as the winning time was 2:03:02 when the world record was 2:03:59.
Kellogg made his bold prediction for a simple reason – there was a huge tailwind in 2011.
Tomorrow, it appears there once again could be another nice tailwind. In the table below, you will see the predicted weather for the start, midpoint, and finish of tomorrow’s race (women’s race starts at 9:32 a.m. ET, men’s race at 10:00 a.m. ET). Below that you will see a map of the course which shows it runs to the northeast.
|Temp||Dew Point||Wind||Wind Gusts|
|Start (Hopkinton – 10:00 a.m. ET)||64 F||60 F||13 mph||27 mph|
|Halfway (Wellesley – 11:00 a.m. ET)*||67 F||59 F||13 mph||24 mph|
|Finish (Copley Square 12:00 p.m. ET)||69 F||56 F||13 mph||21 mph|
*The forecast was given in 2-hour increments, so we just averaged the 10 am and 12 noon forecasts to get the 11 am forecast.
Dark Sky is predicting a wind to the northeast (out of the southwest) of 13 mph throughout the race from start to finish. That is fantastic and the good news. The bad news is mid to high 60s is warmer than ideal for a marathon.
“A 13 mph wind like that would probably help the runners out by about 5 seconds a mile, maybe up to 7 seconds per mile if it’s gusting a lot, but that’s going to be offset by the temperature, which I don’t feel comfortable making any real predictions on as people react differently to temperatures in the 60s. You can’t call that hot, but it’s certainly on the warm side for a marathon,” said John Kellogg when I asked him to comment on the Dark Sky weather forecast. “Temperatures in the 60s with a tailwind isn’t ideal as it isn’t going to be a cooling breeze. It may feel kind of stuffy. The runners will be outrunning the wind as if the reported wind speed is 13 mph, when you come down to head and chest and back level it’s only about 7 mph.”
I then pressed Kellogg to make a prediction as to which would have the bigger impact – the tailwind or the temperatures – and he reluctantly said the following, “It’s probably going to even out – the wind and the temperature. If anything the wind might be a little bigger – maybe overall the weather might help them out a second or two per mile.”
So there you have it. PRs certainly may be possible if the forecast holds. Please note, John Kellogg’s comments are based on there being a wind out of the southwest. Weather.com is predicting the wind will be out of the south which would be more of a crosswind. If that’s true, then the weather might hurt the runners a few seconds a mile.
Talk about the Boston weather on our world-famous fan forum / message board. MB: Boston 2019 Weather Thread