It's hard to find hard statements on this, but it appears to me that even during the day, the net effect of contrails is warming rather than cooling. E.g. http

It's hard to find hard statements on this, but it appears to me that even during the day, the net effect of contrails is warming rather than cooling. E.g. https://phys.org/news/2022-12-airlines-contrails-environmental-problem.html https://phys.org/news/2022-12-airlines-contrails-environment... A small percentage of flights are happening at night, but those are creating the most contrails," Chen said. "And that's the worst time for it to happen." Even contrails during the day are bad, though clouds may be acting to block some sunlight from reaching the surface, Chen said.