Well, they're not his measurements, but on the site "EngineeringToolbox.com" we have a table with a bunch of coefficients of thermal expansion. (I would have referred you to the CRC Handbook, but thermal expansion is one characteristic it does not list for wood.)
Here is the page you are looking for:
https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html
The coefficients of expansion are given as parts-per-million per degree centigrade. If a material has a coefficient of expansion of "30" in the table that means if you heat it by 100 degC it will grow by a factor of 1.003, or if you took it from ice water to boiling water it would grow (in all directions) by 0.3%.
I don't know what the tubes of tube-style cases are constructed of, but fiberglass reinforced ABS has a coefficient of 31 and PVC has a coefficient between 54 and 110. Wood along the grain is listed as 3, so very low. Wood across the grain, which is the direction we're interested in is given as 30. (The type of wood is not specified except it is not fir or pine which are slightly different from just plain "wood".)
This means that if your case is made of reinforced ABS, the cue will fit very, very slightly looser if you go from Antarctica (or Toronto) to boiling hot springs. On the other hand, if you have a PVC-based tube case that is an inch in diameter (just as an example) and the cue has a tenth of an inch gap at freezing, the gap will grow to 1*(1+110*100/1000000)-0.9*(1+30*100/1000000) or 0.108 inches (starting at 0.100 inches) in boiling water. If 8 thousandths is a problem to you in this situation, you have a problem.
The take-away: Do not put your cue into your case when both are much too hot to touch.:grin: