As the days grow longer, some people in Finland clock up to three hours less sleep per night than in winter.
Many are finding themselves sleep deprived this time of year, and Finns often say they’re tired in spring because of a mix of physical and psychological factors.
"When there's more light in the evenings, it has an immediate energising effect, which leads many people to postpone their bedtime," explained Timo Partonen, a research professor at the Finnish Institute for Health and Welfare (THL).
While Statistics Finland's surveys suggest that most Finns sleep roughly the same amount regardless of the season, some sleep two to three hours less per night in summer than winter.
"In the summer, Finns clearly have the most sleep problems — including difficulty falling asleep, fragmented sleep, waking up too early or sleep that doesn't feel refreshing,” he said.
While many people struggle with sleep in the spring due to increased daylight, the environment is rarely the main culprit, according to sleep specialist Henri Tuomilehto.
He said the whole country would be sleeping poorly if light alone were to blame.
"People are often quick to blame their surroundings, whether it's the season, blue light or coffee," Tuomilehto said. "Of course, someone who's a light sleeper will naturally react to things like increased daylight or the clock change. Those individuals should pay extra attention to their sleep by maintaining a consistent sleep schedule and a healthy lifestyle."
According to Tuomilehto, any activity that stimulates brain function in the evening raises a person's alertness level. At first, this can make it harder to fall asleep, but as sleep debt builds up, one may start falling asleep very quickly.
In these situations, the brain remains overactive even during sleep, leading to more frequent awakenings during the night and ultimately poorer quality sleep.
Finland returned to summer time last weekend, when clocks moved forward one hour.
