Dew point is the tempurature the air cannot hold the weight of the water in it. The water then begins to condense and form droplets. This tempurature is always below or equal to the air tempurature.
Propane prices. Maine (ME) propane users spent an average of $2.724 per gallon over the 2012-2013 heating season. This is slightly higher than the 2.436 average for the country as a whole, for the reasons explained above (distance from major supply source, colder climate, higher demand).
Propane Costs for Larger Homes. A 2,000 square foot home in a mild climate would require about 2 million BTUs of propane, and cost $76 per month to heat. A home in a moderate climate would require 4.0 million BTUs, and cost $152 per month.