Category: Extremes affecting New Zealand

Heat wave occuring from September 21 2025 to September 27 2025 at -46.5°S 186.0°E

Download data: JSON

Event type: Heat wave

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

  • New Zealand

Duration: 7 days

Time span: September 21 2025 to September 27 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.0 °C
  • Mean temperature: 11.3 °C
  • Maximum temperature anomaly: 3.3 °C
  • Maximum temperature: 14.6 °C

Event center: -46.5°S 186.0°E

Area affected: 957219 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-21_to_2025-Sep-27_186.0_-46.5

Heat wave occuring from September 20 2025 to September 24 2025 at -33.5°S 172.5°E

Download data: JSON

Event type: Heat wave

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

  • New Zealand

Duration: 5 days

Time span: September 20 2025 to September 24 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 1.9 °C
  • Mean temperature: 17.1 °C
  • Maximum temperature anomaly: 5.1 °C
  • Maximum temperature: 20.3 °C

Event center: -33.5°S 172.5°E

Area affected: 496412 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-20_to_2025-Sep-24_172.5_-33.5

Heat wave occuring from September 19 2025 to September 23 2025 at -53.0°S 176.0°E

Download data: JSON

Event type: Heat wave

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

  • New Zealand

Duration: 5 days

Time span: September 19 2025 to September 23 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.3 °C
  • Mean temperature: 8.3 °C
  • Maximum temperature anomaly: 4.4 °C
  • Maximum temperature: 12.6 °C

Event center: -53.0°S 176.0°E

Area affected: 962415 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-19_to_2025-Sep-23_176.0_-53.0

Heat wave occuring from September 13 2025 to September 17 2025 at -37.5°S 153.0°E

Download data: JSON

Event type: Heat wave

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

  • Australia
  • New Zealand

Duration: 5 days

Time span: September 13 2025 to September 17 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.5 °C
  • Mean temperature: 14.7 °C
  • Maximum temperature anomaly: 6.6 °C
  • Maximum temperature: 21.7 °C

Event center: -37.5°S 153.0°E

Area affected: 1656781 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-13_to_2025-Sep-17_153.0_-37.5

Cold spell occuring from August 24 2025 to September 01 2025 at -57.5°S 149.0°E

Download data: JSON

Event type: Cold spell

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

  • Antarctica
  • Australia
  • New Zealand

Duration: 9 days

Time span: August 24 2025 to September 01 2025

Statistics over entire affected area:

  • Mean temperature anomaly: -3.4 °C
  • Mean temperature: -0.4 °C
  • Minimum temperature anomaly: -6.1 °C
  • Minimum temperature: -9.4 °C

Event center: -57.5°S 149.0°E

Area affected: 3060801 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-Aug-24_to_2025-Sep-01_149.0_-57.5

Heat wave occuring from August 20 2025 to September 11 2025 at -13.0°S 192.5°E

Download data: JSON

Event type: Heat wave

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

  • Australia
  • Fiji
  • New Zealand
  • Tonga

Duration: 23 days

Time span: August 20 2025 to September 11 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 1.7 °C
  • Mean temperature: 20.5 °C
  • Maximum temperature anomaly: 3.6 °C
  • Maximum temperature: 28.0 °C

Event center: -13.0°S 192.5°E

Area affected: 6868306 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-20_to_2025-Sep-11_192.5_-13.0

Heat wave occuring from August 16 2025 to August 29 2025 at -48.0°S 147.5°E

Download data: JSON

Event type: Heat wave

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

  • Australia
  • New Zealand

Duration: 14 days

Time span: August 16 2025 to August 29 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.6 °C
  • Mean temperature: 8.5 °C
  • Maximum temperature anomaly: 8.6 °C
  • Maximum temperature: 19.5 °C

Event center: -48.0°S 147.5°E

Area affected: 7459285 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-16_to_2025-Aug-29_147.5_-48.0

Heat wave occuring from August 14 2025 to August 16 2025 at -49.0°S 172.0°E

Download data: JSON

Event type: Heat wave

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

  • New Zealand

Duration: 3 days

Time span: August 14 2025 to August 16 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.2 °C
  • Mean temperature: 9.5 °C
  • Maximum temperature anomaly: 3.2 °C
  • Maximum temperature: 12.1 °C

Event center: -49.0°S 172.0°E

Area affected: 200558 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-14_to_2025-Aug-16_172.0_-49.0

Heat wave occuring from August 02 2025 to August 08 2025 at -48.0°S 150.5°E

Download data: JSON

Event type: Heat wave

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

  • Antarctica
  • Australia
  • New Zealand

Duration: 7 days

Time span: August 02 2025 to August 08 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 3.0 °C
  • Mean temperature: 6.7 °C
  • Maximum temperature anomaly: 6.1 °C
  • Maximum temperature: 16.0 °C

Event center: -48.0°S 150.5°E

Area affected: 4227888 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-02_to_2025-Aug-08_150.5_-48.0

Heat wave occuring from August 01 2025 to August 07 2025 at -43.5°S 169.0°E

Download data: JSON

Event type: Heat wave

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

  • New Zealand

Duration: 7 days

Time span: August 01 2025 to August 07 2025

Statistics over entire affected area:

  • Mean temperature anomaly: 2.1 °C
  • Mean temperature: 12.6 °C
  • Maximum temperature anomaly: 3.2 °C
  • Maximum temperature: 15.3 °C

Event center: -43.5°S 169.0°E

Area affected: 475009 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-01_to_2025-Aug-07_169.0_-43.5