last month 's average temperature of 56.4 °f -lrb- 13.6 °c -rrb- was the hottest march on record , surpassing the previous record of 2010 by 0.09 °f -lrb- 0.05 °c -rrb- , which is 1.5 °f -lrb- 0.85 °c -rrb- above the average for the 20th century .
last month 's average temperature soared to 56.4 °f -lrb- 13.6 °c -rrb- , which follows earlier announcements from us government scientists that 2014 was the hottest year in modern history .