Michael A. Stivala
Analyst
Great. Thanks, Davin, and good morning. Thank you all for joining us today. The fiscal 2024 heating season presented widespread unseasonably warm weather across the vast majority of our operating territories, with the exception of a 2-week period of extreme cold temperatures in mid-January, during which reported heating degree days were 33% colder than the prior year.
For the fiscal 2024 second quarter, average temperatures were 8% warmer than normal, which followed a first quarter that was also 9% warmer than normal. While the warm weather negatively impacted customer demand for heating purposes, we were once again able to leverage our experience in managing our business through a challenging heating season, and our operating personnel did an outstanding job managing the things they can control, namely keeping safety as their highest priority, providing exceptional service to our customers, managing selling prices and controlling expenses.
In addition, the recent and continued favorable trends in our customer base helped to offset some of the shortfall in heat-related demand. As a result, volumes for the second quarter of fiscal 2024 were just 2.7% below the prior year. Adjusted EBITDA for the quarter was $147 million, down $2 million or 1.3% compared to the prior year second quarter.
In our renewable natural gas operations, we are continuing to install an operational excellence mindset that has made us a leader in the propane industry, including driving efficiencies, modifying our manure collection practices to increase the amount of volatile solids to be processed and identifying additional local dairies in the Stanfield, Arizona area to increase manure intake. As a result, we are continuing to improve the amount of average daily pipeline injected RNG at the Stanfield facility with an average of 1,139 MMBTUs injected per day during the second quarter of fiscal 2024, an improvement of 8.4% compared to the first quarter of fiscal 2024. And with the continued enhancements that we are making, we have additional opportunities to increase production levels even further.
We're also continuing to advance our capital improvement plans for the installation of RNG upgrade equipment at our Columbus, Ohio facility and the construction of our anaerobic digester facility at Adirondack Farms in Upstate New York. We expect both facilities to be completed in the second half of calendar 2025.
Finally, subsequent to the end of the second quarter, we closed on 2 small propane acquisitions in strategic markets in Florida and Nevada, investing a total of approximately $13 million.
So while warm weather weighed on customer demand in the fiscal 2024 heating season, our operational personnel delivered solid results, and we remain steadfast in our commitment to our long-term strategic growth objectives of fostering the growth of our core propane business while making strategic investments in lower carbon renewable energy alternatives. In a moment, I'll come back for some closing remarks. However, at this point, I'll turn it over to Mike Kuglin to discuss the second quarter in more detail. Mike?