The temperature of Europa’s subsurface water ocean, H.J. Melosh, et al, U. Arizona, 2004 (PDF) https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.164.46

The temperature of Europa’s subsurface water ocean, H.J. Melosh, et al, U. Arizona, 2004 (PDF) https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.164.464&rep=rep1&type=pdf https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.16... If I’m reading correctly, the temperature would average around 4°C, below a colder “stratosphere” directly under the ice.