5. Fargo, North Dakota
> Avg. temperature, Sept. 2021: 64.4 °F
> Change from avg. Sept. temperature, 1901-2000: +6.8
> Hottest September on record: 2015 (Avg temperature: 65.1 °F)
4. Dickinson, North Dakota
> Avg. temperature, Sept. 2021: 63.6 °F
> Change from avg. Sept. temperature, 1901-2000: +6.9
> Hottest September on record: 1998 (Avg temperature: 63.9 °F)
3. Colorado Springs, Colorado
> Avg. temperature, Sept. 2021: 68.0 °F
> Change from avg. Sept. temperature, 1901-2000: +7.2
> Hottest September on record: 2019 (Avg temperature: 68.7 °F)
2. Goodland, Kansas
> Avg. temperature, Sept. 2021: 71.4 °F
> Change from avg. Sept. temperature, 1901-2000: +7.2
> Hottest September on record: 2021 (Avg temperature: 71.4 °F)
1. Grand Forks, North Dakota
> Avg. temperature, Sept. 2021: 63.0 °F
> Change from avg. Sept. temperature, 1901-2000: +7.8
> Hottest September on record: 2009 (Avg temperature: 64.1 °F)