For every 10 degrees farenheit the PSI will increase by 1. When they say "cold" they mean the ambient temperature should be around 70 degrees. So at 103 degrees, your tire pressure is reading 3 PSI too high, so that when the temperature does settle down to ~70 degrees your tires will likely read ~32 psi.

There are several things to keep in mind when considering what PSI to run at. Ideally, you would want to run the manufacturer's recommended pressure for the best tire wear characteristics, and increase the pressure if the outside edges are wearing quicker than the inside edges, and decrease the pressure if the inside edge is wearing faster. Best way to arrive at the ideal pressure is if you have a pyrometer. It's a little tool with a needle like tip, you stick it in the tire tread and it'll read the temperature of the tire. Go for a spirited drive for 10-15 minutes, or do your daily commute, and when you stop, measure the inside edge, middle, and outside edge of the tire to get a temperature reading. If the middle is reading HIGHER than the average of the inside and outside, you need to lower your tire pressure. If the outside and inside averages higher than the middle, you need to increase your tire pressure.