First, let’s look at the Average Daily Temperatures for Manhattan from 2014 – 2017 and how that relates to New York’s heat season which begins October 1st and continues through May 31st:
- Between 6:00A.M. – 10:00P.M., inside temperatures are maintained at a minimum of 68 degrees Fahrenheit when the outdoor temperature falls below 55 degrees (orange).
- Between 10:00P.M. – 6:00A.M., inside temperatures are maintained at a minimum of 55 degrees when the outdoor temperature falls below 40 degrees (blue: prior to 2017-2018 heat season).
- NOTE: This has changed to a minimum of 62 degrees, regardless of the outdoor temperature.
January and February obviously have the lowest Average Daily Temperatures, which means they will have the highest number of HDDs. One important takeaway from this chart is how much heating seasons can vary year to year. For example, the Average Daily Temperature was 24⁰F in February 2015, 37⁰F in February 2016 and 41⁰F in February 2017. That’s a 17⁰F swing in only 2 years! It’s important that your boiler system is able to take advantage of the milder heating seasons so that you’re not over paying for fuel.