Time is getting tight for Solar Impulse 2 to cross the Pacific before the days become too short for the voyage to continue safely.

If poor weather conditions persist and Solar Impulse 2 is unable to take off within the the next few weeks, the solar-powered aircraft will have to remain grounded in Japan until next spring. Co-pilot Bertrand Piccard told the Tribune de Geneve that "before August 5, we must have crossed the Pacific or the Atlantic," according to The National.

After Aug. 5, daylight hours will become too short for the aircraft to make the full cross-ocean journey. The announcement comes just days after a scheduled take-off from Japan was canceled due to poor weather conditions.

“There is still a cold front that is blocking our route. Our meteorologists are constantly evaluating alternative routes,” Piccard said.

"[The plane can] fly through clouds for 10 hours, but after that it needs blue skies to recharge its batteries. Otherwise, Andre will have to jump out in a parachute.”

Originally scheduled to fly from China to Hawaii, Solar Impulse made the unplanned stop in Japan due to poor weather conditions. Since then, several anticipated take-offs have been halted due to poor weather. Throughout the planes round-the-world voyage, the plane has faced numerous delays due to safety concerns relating to the weather and other technical issues.

The aircraft took off on its incredible journey from Abu Dhabi on March 9, flying to Muscat. Since then, the plane has traveled to Ahmedabad, India; Varanasi, India; Mandalay, Burma; Chongqing, China; Nanjing, China and most recently the unschedule stop in Nagoya, Japan.

Originally the solar-powered airplane planned to fly all the way from Nanjing, China, to Kalaeloa, Hawaii, a trip anticipated to take five to seven days. However, the plane was forced to land in Japan after just 44 hours and 10 minutes.

Manned by only one pilot at a time, Solar Impulse 2 has been flown by Bertrand Piccard and André Borschberg on alternating segments of the epic trip. The two Swiss natives are also the founders of Solar Impulse.