The ideal temperature for applying exterior oils to wood depends on the type of oil being used. Most exterior oils are typically applied at temperatures between 10 and 25 degrees Celsius, in low humidity conditions.

However, it's important to check the manufacturer's instructions for more precise indications on required temperatures and environmental conditions for effective application and high-quality finishing.

Make sure the wood surface is clean and dry before applying the oil, and that it remains dry for some time after application to allow the oil to penetrate the wood fibers and dry properly.

It's also important to never apply oils to wood when the sun is present, as with all exterior coating products.