Japan's Mt. Fuji reopened Thursday to climbers for the summer season after being closed last year due to the coronavirus pandemic.

With virus countermeasures in place, the most popular of the four routes up the 3,776-meter volcano was opened on the Yamanashi Prefecture side of the world heritage site.

Climbers pose for photos near the summit of Mt. Fuji early in the morning on July 1, 2021. (Kyodo)

Shizuoka Prefecture, which manages the remaining three paths, said it plans to open them July 10. The mountain will be accessible to visitors through Sept. 10.

As part of efforts to reduce the risk of infections, visitors are asked to fill out health forms and check their temperatures before climbing the mountain, according to Yamanashi Prefecture.

People begin climbing Mt. Fuji on its Yamanashi Prefecture side on June 30, 2021, ahead of its public opening on July 1. The highest mountain in Japan was closed to the public last year due to the coronavirus pandemic. (Kyodo) ==Kyodo

The Fuji Subaru Line tollway, a road running halfway up the mountain that is open 24 hours in usual years, has shortened its operating hours from 3 a.m. to 6 p.m. to reduce the number of climbers who try to make quick overnight ascents.

On Thursday, only a few climbers were spotted making their way up the Yoshida route as heavy rain fell in wide areas across Japan. A group of U.S. military personnel based in Japan who climbed to the summit in the early morning expressed regret over the unfortunate weather.

Sota Kodama, 30, a Mt. Fuji guide, urged visitors to be vigilant over the bad weather.

"I would like climbers not to try too hard and to be flexible depending on weather conditions," Kodama said.

Last year, both prefectures closed all four routes amid the coronavirus pandemic for the first time since 1960.