As spring approaches in Japan, the country's weather forecasters face one of their biggest missions of the year: predicting exactly when the famed cherry blossoms will bloom.
Japan's sakura or cherry blossom season is feverishly anticipated by locals and visitors alike. Many tourists plan their entire trips around the blooms and Japanese flock to parks in the millions to enjoy the seasonal spectacle.
"People pay more attention to the cherry blossom season than any other flower in Japan," Mr Ryo Dojo, an official of the statistics unit at the Japan Meteorological Agency, told Agence France-Presse.
The most basic element of predicting when the delicate pink and white petals will begin to unfurl is a large data set of temperatures.
That is because the flowers will come earlier if temperatures rise quickly in spring, Mr Dojo said.
Conversely, if temperatures in the autumn and winter period are higher than usual, the blooms can end up being delayed.
Extreme weather can affect the trees too, with unusual patterns last year prompting some blossoms to appear in October, well before the usual season.
In general, blooms begin as early as March in southern Kyushu and appear as late as May in northernmost Hokkaido.
