Global Warming

US growing season extends by 13 frost-free days

The number of frost-free days in the northern United States has increased by more than 13 days in the past 100 years, according to new research.

The other main areas of the mainland US also saw significant increases in the number of days without frost, essentially the growing season – 10.7 days in the west, 8.6 in a central region and 7.7 days in the south.

Global warming was one of the reasons for the trend, but the researchers also found changes to local cloud cover and atmospheric circulation patterns played a part.