The rise of US heat waves over the past six decades

Average number of heat waves per year

6

6 heat waves

5

4

3

2

1

0

1960s

1970s

1980s

1990s

2000s

2010s

Average duration of heat wave season

68.6

70 days

60

50

40

30

20

10

0

1960s

1970s

1980s

1990s

2000s

2010s

Average number of heat waves per year

6

6 heat waves

5

4

3

2

1

0

1960s

1970s

1980s

1990s

2000s

2010s

Average duration of heat wave season

68.6

70 days

60

50

40

30

20

10

0

1960s

1970s

1980s

1990s

2000s

2010s

Average number of heat waves per year

6

6 heat waves

5

4

3

2

1

0

1960s

1970s

1980s

1990s

2000s

2010s

Average duration of heat wave season

68.6

70 days

60

50

40

30

20

10

0

1960s

1970s

1980s

1990s

2000s

2010s

Average number of heat waves per year

Average duration of heat wave season

6

6 heat waves

70 days

68.6

60

5

50

4

40

3

30

2

20

1

10

0

0

1960s

1970s

1980s

1990s

2000s

2010s

1960s

1970s

1980s

1990s

2000s

2010s

Average number of heat waves per year

Average duration of heat wave season

6

6 heat waves

70 days

68.6

60

5

50

4

40

3

30

2

20

1

10

0

0

1960s

1970s

1980s

1990s

2000s

2010s

1960s

1970s

1980s

1990s

2000s

2010s