Heating Degree Days – and Why October’s Numbers Matter

When we talk about how cold a month gets, one useful measure is heating degree days (HDDs). An HDD shows how much the average outdoor temperature fell below a base value – typically 65 °F in the U.S. The colder the temperature, the higher the HDDs. The more HDDs there are, the more heating (and energy use) is needed.

October is the start of the heating season in many parts of the country. So the HDD numbers for October give propane providers and energy planners an early clue about how cold the season might be and how much heating demand they can reasonably expect.

What the Data Shows
Here are some highlights from recent October HDD trends (by census division and national average) from the National Propane Gas Association (NPGA’s) data: 

• In October 2023, the U.S. average HDD was about 206. 

• That was down from 258 in October 2022, but up from 180 in October 2021. 

• Some regions, like the West North Central, consistently see larger HDDs because of colder climates. 

• In contrast, southern divisions – like the South Atlantic or West South Central regions – show much lower October HDDs, reflecting milder fall weather. 

These regional differences matter because energy demand in colder zones will ramp up faster, and providers must be ready for that increase.

Why Propane Businesses Should Care
Understanding and monitoring HDDs gives propane companies several advantages:

• Better Forecasting
October HDDs help set expectations early. If the month is colder than average, that may hint at a stronger heating season ahead. Providers can adjust supply plans, deliveries, and staffing accordingly.

• Resource Planning
In colder regions, companies might need extra cylinders, trucks, or staff to be ready to go earlier in the season.

• Customer Communication
When customers see that heating demand is rising, businesses can preemptively reach out with service checks, safety reminders, or fill-ups.

• Benchmarking Performance
Comparing the current year’s HDDs vs. those of past years helps providers see whether demand is shifting, possibly because of weather patterns, efficiency improvements, or fuel substitution.

Tips for Using HDD Data Wisely
• Don’t rely on the month of October alone. Track HDDs over the entire heating season (October through March) to see complete trends.

• Compare against a 10-year average to see whether this season is likely colder or warmer than “normal.”

• Segment data by geography. What is considered extreme cold in one region may be thought of as mild for another. Various regions have different standards.

• Correlate HDDs with your internal sales, fill rates, and delivery records. Over time, you’ll see patterns that help with predictive planning.

Conclusion
October heating degree days may seem like just another set of weather numbers, but in the propane world, they carry weight. They offer an early pulse on seasonal demand, signal where to focus resources, and help shape operational readiness. For propane providers who watch these trends carefully, the winter season doesn’t come as a surprise – it comes prepared.

Information for this article was provided by the National Propane Gas Association (NPGA).