reduction in costs at other properties. Included in these amounts were $14.7 million of recoverable property operating expenses incurred during the nine months ended September 30, 2024, compared to $15.5 million for the same period in 2023. In addition, our operating expenses included $4.0 million of property operating expenses from gross leases for the nine months ended September 30, 2024, compared to $4.5 million for the same period in 2023.
Depreciation Expense
Depreciation expense for the nine months ended September 30, 2024 was $30.2 million, compared to $31.1 million for the same period in 2023, a decrease of $0.9 million. The decrease primarily resulted from a full nine months impact during the nine months ended September 30, 2024 from three property dispositions that were completed during the nine months ended September 30, 2023 and the impact from three property dispositions that were completed during the nine months ended September 30, 2024, partially offset by the impact of five properties that were acquired in July 2024.
Amortization Expense
Amortization expense for the nine months ended September 30, 2024 was $11.5 million, compared to $12.8 million for the same period in 2023, a decrease of $1.3 million. The decrease primarily resulted from a full nine months impact during the nine months ended September 30, 2024 from three property dispositions that were completed during the nine months ended September 30, 2023 and the impact from three property dispositions that were completed during the nine months ended September 30, 2024, partially offset by the impact of five properties that were acquired in July 2024.
Interest Expense
Interest expense for the nine months ended September 30, 2024 was $21.1 million, compared to $23.9 million for the same period in 2023, a decrease of $2.8 million. This decrease was due to lower interest rates and lower average borrowings during the nine months ended September 30, 2024, compared to the same period in 2023.
The weighted average interest rate of our debt for the nine months ended September 30, 2024 was 3.93% compared to 4.22% for the same period in 2023. Additionally, the weighted average interest rate and term of our debt was 3.79% and 2.2 years at September 30, 2024.
Income Before (Loss) Gain on Sale of Investment Properties
Income before (loss) gain on sale of investment properties for the nine months ended September 30, 2024 was $5.3 million, compared to $5.6 million for the same period in 2023, a decrease of $0.3 million.
(Loss) Gain on Sale of Investment Properties
During the nine months ended September 30, 2024, we completed three dispositions resulting in an aggregate loss of $1.6 million. In September 2024, we sold a medical office building located in Panama City Beach, Florida receiving gross proceeds of $1.1 million, resulting in a gain of $0.1 million. In July 2024, we sold a medical office building located in Panama City, Florida receiving gross proceeds of $11.0 million, resulting in a gain of $1.7 million. In June 2024, we sold an in-patient rehabilitation facility located in Mishawaka, Indiana receiving gross proceeds of $8.1 million, resulting in a loss of $3.4 million.
During the nine months ended September 30, 2023, we completed three dispositions resulting in an aggregate gain of $15.6 million. In August 2023, we sold a medical office building located in North Charleston, South Carolina receiving gross proceeds of $10.1 million, resulting in a gain of $2.3 million. In June 2023, we sold a portfolio of four medical office buildings located in Oklahoma City, Oklahoma receiving gross proceeds of $66.0 million, resulting in a gain of $12.8 million. In March 2023, we sold a medical office building located in Jacksonville, Florida receiving gross proceeds of $4.4 million, resulting in a gain of $0.5 million.
Net Income
Net income for the nine months ended September 30, 2024 was $3.8 million, compared to $21.2 million for the same period in 2023, a decrease of $17.4 million.