This study examined men's participation and performance in the Boston Marathon. Data from all 368,940 official male finishers in the Boston Marathon from 1897 through 2017 were analyzed using different analyses and regression models for all runners, annual top hundred finishers, annual top ten finishers and annual winners. Effect of calendar year on race time was examined alone, in a uni-variable model, and together with country of origin and weather conditions (average air temperature and precipitation) in a multi-variable model. The mean race time of all finishers increased across calendar years, in line with the participation, but it decreased when we considered the annual winners, 10 and 100 fastest. Kenyans and Ethiopians were the fastest nationalities (p<0.001) when we considered all finishers and the annual top 100 fastest but not when the annual 10 fastest were considered. Air temperature≤8 °C improved (p<0.001) race times compared to air temperature>8°C. Precipitation (>0 mm) improved performance for the annual 100 fastest and annual 10 fastest (p=0.013-0.031) but not for all finishers. Our findings improved the knowledge about the evolution of male marathoners across calendar years, considering as main effects country of origin and particular weather conditions.