September 2023 was the warmest on record

Global average surface temperature

anomalies relative to 1991–2020,

each September

1.0C

0.93C

September 2023

0.5

0

-0.5

-1.0

1940

1960

1980

2000

2020

Global average surface temperature anomalies relative to 1991–2020, each September

1.0C

0.93C

September 2023

0.5

0

-0.5

-1.0

1940

1960

1980

2000

2020