Two Japanese women are perched on Mount Everest looking to set the record for the oldest females to summit the mountain.

Tame Watanabe, 73, and Eiko Funahashi, 72, will wait for the best "weather window," expected around mid-May, to launch their assaults, their organizers said.

Watanabe became the oldest woman to scale the peak in 2002 when she was 63 and reached the top via the normal southeast ridge route.

This time she is trying to better her record from the northern route.

"She reached the Advanced Base Camp on the Tibetan side of the mountain Thursday (April 19)," Ang Tshering Sherpa of Asian Trekking, her organizer, said.

Funahashi's attempt, her third on the 8,848-meter peak after unsuccessful tries in 2006 and 2010, will be made via the southeast ridge route.

Watanabe was born on Nov. 21, 1938, according to travel documents filed with her local organizer.

Funahashi, whose records at Nepal's Tourism Ministry say she is 73, is actually 72, Cosmo Trek, her organizer, said. She was born on July 16, 1939, according to her passport.