Refugees and migrants living in tents on the Greek island of Lesbos were hit with heavy rain and cold weather on Friday.
The ground turned to mud in the olive grove where thousands are camping.
Asylum seekers wore raincoats and took shelter in plastic-covered tents set up near large piles of garbage.
In the early morning hours, more migrants arrived on the overcrowded island on dinghies.
More than 100,000 migrants and refugees are currently in Greece according to UNHCR, almost 40,000 of them stranded on Aegean islands.
The Greek government has started transferring migrants to the mainland to ease overcrowding. They said they intend to transfer 20,000 people by 2020 and plan to speed up returns and the asylum process.
Human rights organisations have repeatedly said conditions on the islands are inhumane and dangerous and the EU needs to share the burden.
European Commissioner for Home Affairs Ylva Johansson visited Greece earlier in December and said a common European policy for migration was urgently needed.