Marathon runners are known for their tendency to compulsively check the weather leading up the big race. Rather than try to cure them of this habit, we decided to help make it easier. The experts over at AccuWeather have provided us with a forecast for the 2014 running of the Boston Marathon, as well as some historical weather data.

The current forecast for Boston on April 21, 2014 is sunny with a high of 52.

This is in line with Boston's average high for April 21st, 58 degrees. The average low for that date is 42.

Here's a look at the weather conditions from recent Boston Marathons, provided by AccuWeather:

 

Date	High	Low	Precip.	Weather
4/15/13	49	38	0.00"	Mostly sunny, breezy, chilly
4/16/12	87	59	Trace	Mostly sunny, hot, record-breaking heat
4/18/11	61	44	Trace	Partly to mostly cloudy, breezy, a shower
4/19/10	61	40	0.00"	Clouds and sun
4/20/09	48	38	0.09"	Increasing clouds, breezy, afternoon and evening showers
4/21/08	52	44	0.00"	Clouds and sun
4/16/07	48	42	0.93"	Partly to mostly cloudy, AM wind and heavy rain
4/17/06	53	43	0.01"	Partly to mostly cloudy, breezy, evening shower
4/18/05	66	51	0.00"	Partly cloudy

You'll note that there was only heavy rain 1 day out of the 9 (11%), and anything more than a trace only 3 out of the 9 (33%). So, although there aren't average daily precipitation chances stored on file, chances of heavy rain are small based on what's happened in the past nine years.

After the tailwind in 2011 and the heatwave in 2012, many were saying that Boston had the most bizarre weather of any of the major marathons. But it turns out that it's not as crazy as you think; the weather on Patriots' Day in Massachusetts has about the same variation as Chicago and New York City when they host their fall marathons.