During 2010–2015, a total of 2,244 deaths resulted from unintentional carbon monoxide poisoning, with the highest numbers of deaths each year occurring in winter months.
In 2015, a total of 393 deaths resulting from unintentional carbon monoxide poisoning occurred, with 36% of the deaths occurring in December, January, or February.
Source: https://www.cdc.gov/mmwr/volumes/66/wr/mm6608a9.htm
NCHStats 