Night-Shift Farms: Japan’s Farmers Go Nocturnal as Deadly Heatwaves Intensify

Long after sunset, Motoaki Iijima’s greenhouse north of Tokyo glows under halogen lamps as he harvests pink and orange gerberas, choosing the cooler night over a daytime sun that can be lethal. Across Japan, farmers from flower and asparagus growers to poultry producers are reshaping the workday as heatwaves grow hotter and more frequent.

Changing The Agrarian Clock

What used to be the busiest hours of the day are now the most dangerous. Farmers are shifting tasks to nights and early mornings to protect crops, livestock and themselves. Iijima, 36, converted his family’s centuries-old rice land in Nikko into a flower farm about a decade ago. After a part-time worker suffered heatstroke in a greenhouse three summers ago, he changed operations to avoid peak heat.

Outdoor temperatures above 35°C (95°F) — increasingly common in his area — can push greenhouse interiors above 40°C. Iijima now works through the night and stops when the morning sun becomes punishing. “The hours around dusk are really precious. That's when we can be outside,” he says, wiping sweat beneath rows of lamps. “We’ve gradually become nocturnal. It’s about protecting our bodies, and ultimately, our lives.”

An Ageing Workforce At Greater Risk

Japan is especially exposed: about 70% of its farmers are aged 65 or older, a demographic more vulnerable to heat stress. High humidity amplifies the danger, and the human toll is rising. A record 59 agricultural workers died from extreme heat in 2024 — more than double the toll in 2021.

Heat also hits productivity. Lancet Countdown estimates heat exposure cost Japan’s agricultural sector 926 million labour hours in 2024 — time workers could not safely spend in the fields. Across all sectors, labour hours lost to heat nearly doubled versus the 1990s average, equivalent to roughly $46 billion in lost income, or about 1% of Japan’s GDP.

On-the-Ground Adaptations

On Iijima’s farm, workers start up to two hours earlier or work overnight. Veteran worker Miyoko Asada, 68, arrives just after sunrise to harvest asters before temperatures climb. A few towns away, poultry farmer Tetsuya Usuba still bears the trauma of losing more than 500 laying hens during a three-day heat spell six summers ago. His current routine is rigid: at 2:30 a.m. lights switch on in two barns to wake 4,400 caged hens so they will eat before heat reduces their appetite. He has added fans, waters metal roofs, and supplements drinking water with citric acid — yet sudden spikes above 35°C still cost him 130 birds last month.

"Summer has become a new threat to producers like us, something as scary as an outbreak of avian influenza," Usuba says, watching birds pant with open beaks as the thermometer read 33°C one recent afternoon.

Policy And Technology Responses

The government introduced new workplace regulations in 2025 requiring employers to set up heatstroke reporting procedures and emergency response plans. Japan is also promoting smart farming technologies — including drones and robots — to reduce direct worker exposure to dangerous heat. But many farms, especially smaller operations, still rely on manual measures and altered schedules.

In the early morning on Iijima’s farm, workers hurriedly inspect harvested flowers for wilting leaves before loading them onto trucks. It is not yet 8 a.m., and the morning remains bearable — but everyone knows the heat will return soon.