We are always emphasizing what perfect conditions are in climbing without really understanding what that means. Low temperatures are not the only thing that could constitute what perfect is. With lower temperatures come higher dew point numbers.
Also sometimes higher humidity is more helpful than lower depending on rock type or skin conditions. Over all, it is best to monitor these factors while climbing and note and record when things feel good.
Personally mid 50 degree fahrenheit with relative humidity of 30% is really really comfortable for long days climbing. While during certain times a higher temperatures are good for long climbs or demanding sport routes.
Dew point can be a killer. Keep an eye at the dew point. While waking up for those cold conditions might see like the move, those periods of time the rock could be too cold and capturing moisture. Think of a cup of ice water on a hot day. The cup will condensate and so will a boulder under the right conditions. You will want the dew point far away from air temperature to ensure dry holds.
What the point is, having a good way to record humidity and temperatures via a hydrometer will help you gauge when conditions will be best for you. These are cheap and small and connect with your phone. We curated a couple devices that are cheap and very reliant below. They pair great with our ticklist journal.
We are always obsessing over conditions during our project sessions. These help us to keep track of temp and humidity during our sessions.
Govee Hygrometer Thermometer Mini
Govee Hygrometer Thermometer w/ LCD