Category: Extremes affecting United States

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: October 02 2025 to October 05 2025

Statistics over entire affected area:

• Mean temperature anomaly: 5.5 °C
• Mean temperature: 22.6 °C
• Maximum temperature anomaly: 9.0 °C
• Maximum temperature: 25.6 °C

Event center: 35.5°N 258.0°E

Area affected: 52111 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-Oct-02_to_2025-Oct-05_258.0_35.5

Download data: JSON

Event type: Heat wave

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

• United States

Duration: 8 days

Time span: October 02 2025 to October 09 2025

Statistics over entire affected area:

• Mean temperature anomaly: 4.5 °C
• Mean temperature: 6.3 °C
• Maximum temperature anomaly: 10.0 °C
• Maximum temperature: 11.2 °C

Event center: 60.0°N 207.0°E

Area affected: 132841 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-Oct-02_to_2025-Oct-09_207.0_60.0

Download data: JSON

Event type: Heat wave

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

• United States

Duration: 7 days

Time span: September 30 2025 to October 06 2025

Statistics over entire affected area:

• Mean temperature anomaly: 1.8 °C
• Mean temperature: 11.4 °C
• Maximum temperature anomaly: 2.4 °C
• Maximum temperature: 12.1 °C

Event center: 58.5°N 213.0°E

Area affected: 50688 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-30_to_2025-Oct-06_213.0_58.5

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: September 28 2025 to October 02 2025

Statistics over entire affected area:

• Mean temperature anomaly: 1.9 °C
• Mean temperature: 28.1 °C
• Maximum temperature anomaly: 3.5 °C
• Maximum temperature: 28.6 °C

Event center: 28.0°N 266.5°E

Area affected: 133067 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-28_to_2025-Oct-02_266.5_28.0

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: September 24 2025 to September 27 2025

Statistics over entire affected area:

• Mean temperature anomaly: 4.6 °C
• Mean temperature: 26.4 °C
• Maximum temperature anomaly: 6.6 °C
• Maximum temperature: 28.6 °C

Event center: 34.5°N 280.5°E

Area affected: 101166 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-24_to_2025-Sep-27_280.5_34.5

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