Many across the globe continue to await the rescue of 12 boys and their soccer coach from a cave in Thailand. As workers try to help their escape, a new obstacle begins to form as monsoon season approaches.

CNN reported on Saturday that dark clouds are forming near in the cave in the area of Mae Sai in northern Thailand. Monsoon season begins in July and lasts until October. Weather reports for the week predict heavy rains starting Saturday evening and continuing for the rest of the week. The addition of rain will make rescue efforts even more difficult as water levels within the cave will begin to rise soon.

The 12 boys, — all between the ages of 11 and 16 — and their 25-year-old coach found themselves stuck in a Tham Luang Nang Non cave on June 23 after they were exploring the cave system and had to head for higher ground when it started to rain heavily. The group was missing for nine days but then discovered on July 2.

Since then, rescue teams began on various strategies to save the group. Thai soldiers, civilians, engineers, and even Tesla CEO Elon Musk have helped in finding a way to get the boys and their coach out of the cave. Helicopters and drones were used to find possible exit ways while divers are working to educate the group on how to scuba dive, but the children’s physical condition along with the natural hazards of the flooded cave make the situation dire.

When the waters rise, time will be of the essence to save the group from the cave. Tough decisions will have to be made in hopes of having a successful rescue.

Musk confirmed on Friday engineers from SpaceX and Boring Company are en route to Thailand to help. He’s suggested different strategies on his Twitter feed including an inflatable nylon tube inserted into the cave to create something similar to a “bouncy castle.”