On 1 July 2025, NIWA merged with GNS Science to become Earth Sciences New Zealand.

Figure 3: Week-average nighttime PM2.5 (between 8pm and 4am) for each of the four weeks of lockdown compared to the average for the same weeks 2017-19.

Figure 3: Week-average nighttime PM2.5 (between 8pm and 4am) for each of the four weeks of lockdown compared to the average for the same weeks 2017-19. [NIWA]