Extreme heat shifts urban spending to evening hours, study finds

Analysis of bank card transactions from Melbourne, Sydney, and Adelaide over two years showed that overall spending fell 7% during heat waves, with the sharpest declines between noon and 6 p.m. Spending partially shifted to cooler evening periods or adjacent days. The authors argue that as extreme heat becomes more common, cities must adapt to accommodate more nighttime activity.

The study tracked point-of-sale transactions in three-hour intervals across two years, capturing nearly all card spending in the three Australian cities. Adelaide experienced the most extreme heat days at 27, followed by Melbourne with 20 and Sydney with 15. While air-conditioned department stores still saw a 35% drop in afternoon sales, convenience stores proved more resilient, suggesting some purchases were merely postponed rather than abandoned.

Cities elsewhere are already adapting. Dubai has opened floodlit beaches that stay accessible overnight, while Paris and Toulouse extend park and swimming hours. Seoul keeps over 120 libraries open until 10 p.m. as climate shelters. However, researchers note most cities still lack comprehensive planning for a future where afternoon activity becomes impractical.