turntable sounds better on warm summer nights

On warm summer evenings it has more presence than cooler winter evenings.I presume this has something to do with the tracking weight of my clearaudio virtuoso wood MM cartridge on warm evenings when the room gets to about 75. If it sounds better in the summer do I add or subtract weight in the winter when the room is about 5 degrees F cooler, in order to get the same summer sound?
Would humidity be the reaon?
add... more beer ;~)
I second Chadnliz's observation. Also, do you listen LATER on summer nights, when the power grid is cleaner? Do you have electric heat in the winter? Can you check the voltage at the outlet that powers your system in both summer & then in winter?
There are many things in play here. Warm summer nights might mean that your speakers and electronics too are operating differently...your electricity and any other permutation could change the sound.
Does listening to and enjoying music play any part in your activities?
Did you see the other thread about getting a humidifier to improve sound quality?

Could it be changed bearing tolerances due to dissimilar metals ? My rega has a brass bearing housing, with a steel shaft: these metals expand and contract differently. It's pretty common to have a brass or bronze housing with a steel shaft, and a steel, ceramic, or saphire bearing ... all different materials.

One of the Brinkmann turntables has a small heater in the bearing housing to maintain a constant temperature. It seems a bit extreme to me, but perhaps there is a measurable difference in performance.

While factors like those mentioned above are probably all contributing (including the beer!), your speculation about temperature + Chadnliz's speculation about humidity are probably the biggest factors, at least IME.

The suspension in a cartridge is made from an elastomer. Elastomers are more sensitive to temp/humidity changes than other solid materials. When temps and/or humidity rise, most elastomers soften. With less resistance from the suspension, the cantilever can be deflected more easily and reach greater excursions from a given force (ie, groove modulation). Result: faster transient responses and greater dynamic range from the same LP.

Every cartridge I've used (dozens) has required more VTF and antiskating in the winter (cold and dry) and less in the summer (hot and damp). Depending on the climate and the cartridge, the VTF differential can be .30g or even more.

Experiment a little as the year goes 'round. You'll learn more about optimizing your rig and hear more music at all times, which might even satisfy Pbb. ;-)

My wife sounds better on warm summer nights, go figgur!
All the comments here on time of day and year, temp and humidity effects on cantilever suspension, power grid, etc. make sense. How about the effect of heat and humidity on a wood-bodied cartridge?

My brother's cello always sounded more sonorous and resonant on a warm muggy day.
"My wife sounds better on warm summer nights, go figgur!"

Yeah, she does!
completely of topic, but as a kid I once left a friends fender amp in trunk of my car on a hot summer day.

We took it out and played guitar through it and couldn't believe how good it sounded.
My wife talks so much, I cant even hear the silent black
backround. Let me acquit myself here, I have a male buddy
who is even worse. Please see my related thread, "Take my
wife, OOPS, Wool carpet, please.