Monstera Leaves Producing Water. As Monstera deliciosa ages the new leaves will have more and more fenestrations holes and slits among the leaves. A lack of water and humidity can have a similar effect.
While it might be alarming at first a sweating Monstera is actually a completely normal common occurrence that happens year-round. Keep in mind that after a leaf develops it will not change. You may need to water less in the winter so always check the soil before you add more water.
Why is my Monstera getting yellow leaves.
This is just to help the water evaporate faster. As the plant matures the newer leaves will slowly have more and more fenestrations. Use room-temperature filtered water when watering your plants or let the water sit out overnight so chemicals like chlorine can evaporate. I put it in a vase thinking the leaves would look nice until it died.