Category: Extremes affecting United States

Cold spell occuring from November 29 2025 to December 01 2025 at 48.5°N 255.0°E

Download data: JSON

Event type: Cold spell

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

  • Canada
  • United States

Duration: 3 days

Time span: November 29 2025 to December 01 2025

Statistics over entire affected area:

  • Mean temperature anomaly: -11.7 °C
  • Mean temperature: -16.0 °C
  • Minimum temperature anomaly: -19.5 °C
  • Minimum temperature: -25.1 °C

Event center: 48.5°N 255.0°E

Area affected: 57710 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: Cold_spell_2025-Nov-29_to_2025-Dec-01_255.0_48.5

Heat wave occuring from November 26 2025 to January 09 2026 at 43.5°N 172.5°E

Download data: JSON

Event type: Heat wave

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

  • Russian Federation
  • United States

Duration: 45 days

Time span: November 26 2025 to January 09 2026

Statistics over entire affected area:

  • Mean temperature anomaly: 6.9 °C
  • Mean temperature: 2.7 °C
  • Maximum temperature anomaly: 34.5 °C
  • Maximum temperature: 26.0 °C

Event center: 43.5°N 172.5°E

Area affected: 12313111 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-Nov-26_to_2026-Jan-09_172.5_43.5

Heat wave occuring from November 25 2025 to November 29 2025 at 35.0°N 239.0°E

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: November 25 2025 to November 29 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.1 °C
  • Mean temperature: 17.3 °C
  • Maximum temperature anomaly: 4.6 °C
  • Maximum temperature: 18.7 °C

Event center: 35.0°N 239.0°E

Area affected: 132868 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-Nov-25_to_2025-Nov-29_239.0_35.0

Heat wave occuring from November 22 2025 to November 24 2025 at 49.0°N 262.0°E

Download data: JSON

Event type: Heat wave

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

  • Canada
  • United States

Duration: 3 days

Time span: November 22 2025 to November 24 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 8.1 °C
  • Mean temperature: 3.2 °C
  • Maximum temperature anomaly: 11.2 °C
  • Maximum temperature: 7.1 °C

Event center: 49.0°N 262.0°E

Area affected: 208931 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-Nov-22_to_2025-Nov-24_262.0_49.0

Heat wave occuring from November 20 2025 to November 23 2025 at 66.0°N 215.0°E

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: November 20 2025 to November 23 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 12.4 °C
  • Mean temperature: -7.8 °C
  • Maximum temperature anomaly: 17.8 °C
  • Maximum temperature: -3.9 °C

Event center: 66.0°N 215.0°E

Area affected: 57091 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-Nov-20_to_2025-Nov-23_215.0_66.0

Heat wave occuring from November 20 2025 to November 24 2025 at 50.5°N 242.0°E

Download data: JSON

Event type: Heat wave

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

  • Canada
  • United States

Duration: 5 days

Time span: November 20 2025 to November 24 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 6.2 °C
  • Mean temperature: 1.8 °C
  • Maximum temperature anomaly: 8.1 °C
  • Maximum temperature: 5.7 °C

Event center: 50.5°N 242.0°E

Area affected: 95936 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-Nov-20_to_2025-Nov-24_242.0_50.5

Cold spell occuring from November 19 2025 to November 23 2025 at 31.0°N 244.5°E

Download data: JSON

Event type: Cold spell

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

  • Mexico
  • United States

Duration: 5 days

Time span: November 19 2025 to November 23 2025

Statistics over entire affected area:

  • Mean temperature anomaly: -4.7 °C
  • Mean temperature: 10.8 °C
  • Minimum temperature anomaly: -7.7 °C
  • Minimum temperature: 4.0 °C

Event center: 31.0°N 244.5°E

Area affected: 68173 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: Cold_spell_2025-Nov-19_to_2025-Nov-23_244.5_31.0

Cold spell occuring from November 11 2025 to November 14 2025 at 27.0°N 278.5°E

Download data: JSON

Event type: Cold spell

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

  • Bahamas
  • United States

Duration: 4 days

Time span: November 11 2025 to November 14 2025

Statistics over entire affected area:

  • Mean temperature anomaly: -4.5 °C
  • Mean temperature: 19.0 °C
  • Minimum temperature anomaly: -11.7 °C
  • Minimum temperature: 7.8 °C

Event center: 27.0°N 278.5°E

Area affected: 386078 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: Cold_spell_2025-Nov-11_to_2025-Nov-14_278.5_27.0

Heat wave occuring from November 04 2025 to November 08 2025 at 31.0°N 256.0°E

Download data: JSON

Event type: Heat wave

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

  • Mexico
  • United States

Duration: 5 days

Time span: November 04 2025 to November 08 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 5.3 °C
  • Mean temperature: 20.4 °C
  • Maximum temperature anomaly: 8.1 °C
  • Maximum temperature: 23.7 °C

Event center: 31.0°N 256.0°E

Area affected: 101711 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-Nov-04_to_2025-Nov-08_256.0_31.0

Heat wave occuring from November 02 2025 to November 06 2025 at 39.0°N 253.5°E

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: November 02 2025 to November 06 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 6.6 °C
  • Mean temperature: 4.8 °C
  • Maximum temperature anomaly: 8.8 °C
  • Maximum temperature: 11.3 °C

Event center: 39.0°N 253.5°E

Area affected: 87967 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-Nov-02_to_2025-Nov-06_253.5_39.0