Worldwide, it was the warmest September on record, the National Oceanic and Atmospheric Administration said Friday.
Averaging 1.13 degrees Fahrenheit (0.63 degree Celsius) above normal for the month, it was the warmest September since the beginning of reliable records in 1880, according to NOAA's National Climatic Data Center.
The second warmest September was in 2003 with an average temperature of 1.02 degrees Fahrenheit (0.57 Celsius) above the mean.
For the United States it was the fourth warmest September on record.
The average US temperature for the month was 2.6 degrees (1.4 C) above average.
Only the West Coast and parts of the Rockies were near normal. Louisiana had its warmest September in 111 years of national records and an additional 27 states ranked much above average.
Some cities also set new records for warmest average September temperatures including: Houston-Galveston, Texas; London, Kentucky; Shreveport, Louisiana; and Raleigh-Durham, North Carolina.
For the month, rain and snowfall across the country were below average, with unusually dry conditions for much of the East Coast and parts of the Plains and Northwest. Georgia, South Carolina and Maryland had their driest September on record.