BOSTON – As the Northeast continues to ride a weather roller coaster, conditions for the 129th Boston Marathon on Monday are shaping up to be ideal for runners and a bit cool for spectators.According to the FOX Forecast Center, temperatures at the starting line in Hopkinton are expected to begin in the lower 40s, with highs that will only reach the mid-50s by the time the first runners cross the finish line on Boylston Street in Boston.The race is scheduled to occur after a frontal boundary pushes through, which allowed temperatures to reach the mid-80s over the Easter weekend and plunge by more than 40 degrees to start the week.While temperatures will likely be a few degrees below the climatological average for late April, the cool, dry air is widely considered optimal for running.HOW WEATHER CAN HELP OR HURT ATHLETES COMPETING IN THE NEW YORK CITY TRIATHLONThe 26.2-mile course, which winds through townships in eastern Massachusetts, has long tested athletes’ ability to compete against the terrain and Mother Nature.Over the event’s 127-year history, at least a dozen races have been affected by falling snow or driving rain, while many others have contended with extreme heat.According to the Boston Athletic Association, the warmest marathon on record occurred in 1905, when the temperature is believed to have approached 100 degrees.More recently, the 2012 race began with a starting temperature of 75 degrees and peaked at 89 degrees by the afternoon, forcing thousands of runners to seek medical attention.Despite the historical weather hurdles, Boston Marathon participants have set records for their performances.In 2011, Geoffrey Mutai of Kenya ran the course in 2:03:02, and on the women’s side, Ethiopia’s Buzunesh Deba set the course record in 2014 with a time of 2:19:59.The race, first run in 1897, draws participants from over 100 countries and serves as a qualifying event for many Olympic hopefuls.DID THE NATIONAL WEATHER SERVICE CAPTURE A PHOTO OF BIGFOOT DURING A PENNSYLVANIA STORM SURVEY?The first group of professional men and women is slated to start between 9 a.m. and 10 a.m., with all participating categories underway by around 11:15 a.m.The race also coincides with Patriots’ Day, which commemorates the start of the American Revolution and is considered a holiday in Massachusetts.