Does Cold Actually Affect the Level Gauge on a Propane Tank?
Propane is similar to nearly all other types of materials in that it is affected by cold temperatures. The propane gas contracts as the temperature declines. That reduced level of gas inside the tank is reflected by the gauge which reflects the tank level. Often, this occurs whenever a homeowner checks the gauge during cold climate and sees the amount of the tank level before and after delivery. Depending on the weather conditions, the level on the tank may not go up as much as anticipated.

Propane Tank Level Gauge
The propane tank's gauge shows you what portion of the tank is full. Usually, tanks are not filled over 80% so as to enable the gas to expand during hot days. For instance, a 500 gallon tank, at a reading of 80% at normal temperatures reflects about 400 gallons of propane inside the tank. This is roughly the amount which could be stored.

Normal Temperatures
The website Propane 101, that is operated by the propane industry, considers an exterior temperature of 60 degrees to be the reference or baseline point. For instance, if the gauge reads 50% of capacity on a day when the temperature is close to 60 degrees, then a 500 gallon tank would have around 250 gallons of propane. If the temperature that day is much lower than 60 degrees, the gauge would read lower. Also, if the temperature is a lot higher than 60 degrees, the gauge would actually read higher since the gas expanded.

Effect of Contraction and Expansion
Based on the information provided by the propane industry web site, the amount of energy contained in the tank does not actually change when the gas contracts or expands. The amount of propane itself has not changed, but just the density of the gas has changed.

Cold-Weather Delivery
If a homeowner orders 100 gallons of propane to be delivered, they would receive 424 pounds of propane. If the homeowner has a 1000 gallon propane tank, they could expect the gauge to go up by 10% with the delivery of 100 gallons. These numbers will be correct if the temperatures were close to 60 degrees at the time of delivery. If the delivery took place during colder weather, these chillier temperatures will cause a smaller increase reading on the propane gauge.