Category: Heat waves affecting United States

Download data: JSON

Event type: Heat wave

Countries affected (identified with ArcGIS Online; provided only for geographical reference):

• United States

Duration: 9 days

Time span: September 17 2025 to September 25 2025

Statistics over entire affected area:

• Mean temperature anomaly: 4.1 °C
• Mean temperature: 29.9 °C
• Maximum temperature anomaly: 6.0 °C
• Maximum temperature: 31.3 °C

Event center: 31.0°N 263.5°E

Area affected: 80454 km$^2$

Fig. 1: Map of most extreme temperature anomalies (standardized) experienced during the event. The purple star indicates the center of the extreme event. Green hatching illustrates all areas under the effect of extremes at some time during the event.

Fig. 2: Evolution of temperature at the center of the event. The climatological percentile distribution is illustrated with color shadings.

Fig. 3: Maps illustrating the evolution of standardized temperature anomalies during the event.

Event ID: Heat_wave_2025-Sep-17_to_2025-Sep-25_263.5_31.0

Download data: JSON

Event type: Heat wave

Countries affected (identified with ArcGIS Online; provided only for geographical reference):

• United States

Duration: 5 days

Time span: August 31 2025 to September 04 2025

Statistics over entire affected area:

• Mean temperature anomaly: 5.0 °C
• Mean temperature: 7.9 °C
• Maximum temperature anomaly: 8.3 °C
• Maximum temperature: 12.5 °C

Event center: 71.0°N 205.5°E

Area affected: 90988 km$^2$

Fig. 1: Map of most extreme temperature anomalies (standardized) experienced during the event. The purple star indicates the center of the extreme event. Green hatching illustrates all areas under the effect of extremes at some time during the event.

Fig. 2: Evolution of temperature at the center of the event. The climatological percentile distribution is illustrated with color shadings.

Fig. 3: Maps illustrating the evolution of standardized temperature anomalies during the event.

Event ID: Heat_wave_2025-Aug-31_to_2025-Sep-04_205.5_71.0

Download data: JSON

Event type: Heat wave

Countries affected (identified with ArcGIS Online; provided only for geographical reference):

• United States

Duration: 6 days

Time span: August 30 2025 to September 04 2025

Statistics over entire affected area:

• Mean temperature anomaly: 4.8 °C
• Mean temperature: 30.1 °C
• Maximum temperature anomaly: 7.0 °C
• Maximum temperature: 34.3 °C

Event center: 36.5°N 240.0°E

Area affected: 54024 km$^2$

Fig. 1: Map of most extreme temperature anomalies (standardized) experienced during the event. The purple star indicates the center of the extreme event. Green hatching illustrates all areas under the effect of extremes at some time during the event.

Fig. 2: Evolution of temperature at the center of the event. The climatological percentile distribution is illustrated with color shadings.

Fig. 3: Maps illustrating the evolution of standardized temperature anomalies during the event.

Event ID: Heat_wave_2025-Aug-30_to_2025-Sep-04_240.0_36.5

Download data: JSON

Event type: Heat wave

Countries affected (identified with ArcGIS Online; provided only for geographical reference):

• United States

Duration: 6 days

Time span: August 15 2025 to August 20 2025

Statistics over entire affected area:

• Mean temperature anomaly: 3.6 °C
• Mean temperature: 26.4 °C
• Maximum temperature anomaly: 5.3 °C
• Maximum temperature: 28.9 °C

Event center: 37.5°N 277.5°E

Area affected: 78778 km$^2$

Fig. 1: Map of most extreme temperature anomalies (standardized) experienced during the event. The purple star indicates the center of the extreme event. Green hatching illustrates all areas under the effect of extremes at some time during the event.

Fig. 2: Evolution of temperature at the center of the event. The climatological percentile distribution is illustrated with color shadings.

Fig. 3: Maps illustrating the evolution of standardized temperature anomalies during the event.

Event ID: Heat_wave_2025-Aug-15_to_2025-Aug-20_277.5_37.5

Download data: JSON

Event type: Heat wave

Countries affected (identified with ArcGIS Online; provided only for geographical reference):

• United States

Duration: 4 days

Time span: August 15 2025 to August 18 2025

Statistics over entire affected area:

• Mean temperature anomaly: 1.3 °C
• Mean temperature: 29.6 °C
• Maximum temperature anomaly: 1.8 °C
• Maximum temperature: 30.0 °C

Event center: 28.0°N 266.0°E

Area affected: 133962 km$^2$

Fig. 1: Map of most extreme temperature anomalies (standardized) experienced during the event. The purple star indicates the center of the extreme event. Green hatching illustrates all areas under the effect of extremes at some time during the event.

Fig. 2: Evolution of temperature at the center of the event. The climatological percentile distribution is illustrated with color shadings.

Fig. 3: Maps illustrating the evolution of standardized temperature anomalies during the event.

Event ID: Heat_wave_2025-Aug-15_to_2025-Aug-18_266.0_28.0