Japan's Meteorological Agency says central Tokyo hasn't seen so little sun in more than three decades.
Agency officials say the skies over the Pacific coast in northern and eastern Japan have been mostly rainy or cloudy since late last month.
The metropolis had less than three hours total of sunshine over a 17-day stretch. That ties the longest spell on record, set in 1988. Gray skies are forecast to continue for about a week.
Agency officials warn that the unusual weather could affect crop production.