Below are ASRAE charts offering OD design temperatures. You may find more accurate information for rural areas not listed below.

Here is a list of cooling and heating design temps by State and County

Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, and installations should be reviewed on a per-job basis. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for improper information, application, damage to property, or bodily injury from applied information found on this website, as a professional should review it.