In 1976 the wettest month on record took place in July, with of rain, more than half the median yearly value of ; however the average wettest month is September with . The warmer months of the year are typically wetter than the cooler ones. Cold fronts in winter have the possibility of drastically reducing temperatures in the area, and are responsible for the little rainfall of such period. Even snowfall has occurred in Monclova some winters, although most years it is a phenomenon reserved only to the nearby mountains. Precipitation occurs an average of 47 days, out of which 6 will be thunderstorms and at least one day with hail.