Interest expense on deposits increased $2.5 million, or 36.8%, to $9.4 million for the three months ended September 30, 2024 compared to $6.9 million for the three months ended September 30, 2023. The increase was driven by higher rates paid on money market accounts and time deposits and, to a lesser extent, increases in the average balances of such deposits. Specifically, rates on money market accounts and time deposits increased by 68 basis points and 62 basis points, respectively, during the three months ended September 30, 2024, compared to the same period in 2023. The average balance of time deposits increased $53.6 million, or 11.7%, to $512.2 million during the three months ended September 30, 2024, compared to $458.6 million during the same period in 2023. The average balance of money market accounts increased $41.1 million, or 6.6%, to $664.1 million during the three months ended September 30, 2024, compared to $623.0 million during the same period in 2023.
The average rate paid on all interest-bearing deposits increased by 60 basis points to 2.45% for the three months ended September 30, 2024, compared to 1.85% for the three months ended September 30, 2023. The average balance of interest-bearing deposits totaled $1.5 billion for both the three months ended September 30, 2024 and the three months ended September 30, 2023, though there were shifts in the deposit mix, with average balances for money market and time deposits increasing and those for savings and NOW accounts decreasing. Additionally, the average balance of noninterest-bearing deposits decreased $58.9 million, or 8.7%, to $615.8 million for the three months ended September 30, 2024, compared to $674.8 million for the three months ended September 30, 3023. These shifts were due to customers seeking to place excess funds in higher yielding deposit accounts. The overall average cost of deposits for the three months ended September 30, 2024 and 2023 was 1.75% and 1.27%, respectively.
Interest expense on borrowings remained relatively flat, increasing $2,000, or 0.21%, to $1.1 million for the three months ended September 30, 2024, compared to the three months ended September 30, 2023. The average cost of total borrowings increased to 6.13% for the three months ended September 30, 2024, compared to 6.09% for the three months ended September 30, 2023. The average balance of borrowings decreased $141,000 to $72.3 million during the three months ended September 30, 2024, compared to the three months ended September 30, 2023.
Interest expense increased $10.2 million, or 51.6%, to $30.0 million for the nine months ended September 30, 2024, compared to $19.8 million for the nine months ended September 30, 2023, reflecting higher funding costs primarily related to increased market rates of interest payable on money market and time deposits, as well as an increase in the average balance of time deposits. The average rate paid on interest-bearing liabilities for nine months ended September 30, 2024 was 2.52%, compared to 1.75% for nine months ended September 30, 2023. Total average interest-bearing liabilities increased $79.2 million, or 5.24%, to $1.6 billion for the nine months ended September 30, 2024, compared to $1.5 billion for the nine months ended September 30, 2023.
Interest expense on deposits increased $10.2 million, or 61.8%, to $26.7 million for the nine months ended September 30, 2024, compared to $16.5 million for the nine months ended September 30, 2023. The increase was driven by higher rates paid on money market accounts and time deposits and, to a lesser extent, an increase in the average balance of time deposits. Specifically, rates on money market accounts and time deposits increased by 83 basis points and 97 basis points, respectively, during the nine months ended September 30, 2024, compared to the same period in 2023. The average balance of time deposits increased $99.4 million, or 24.4%, to $506.4 million during the nine months ended September 30, 2024, compared to $406.9 million during the same period in 2023.
The average rate paid on all interest-bearing deposits increased by 82 basis points to 2.35% for the nine months ended September 30, 2024, compared to 1.53% for the nine months ended September 30, 2023. The average balance of interest-bearing deposits totaled $1.5 billion for the nine months ended September 30, 2024, compared to $1.4 billion during the same period in 2023. Meanwhile, the average balance of noninterest-bearing deposits decreased $72.5 million, or 10.4%, to $625.3 million for the nine months ended September 30, 2024, compared to $697.9 million for the nine months ended September 30, 3023. The overall average cost of deposits for the nine months ended September 30, 2024 and 2023 was 1.66% and 1.03%, respectively.
Interest expense on borrowings remained relatively flat, increasing $22,000, or 0.67%, to $3.3 million for the nine months ended September 30, 2024, compared to the nine months ended September 30, 2023. The average cost of total borrowings increased to 6.15% for the nine months ended September 30, 2024, compared to 6.10% for the nine months ended September 30, 2023. The average balance of borrowings decreased $269,000 to $72.3 million during the nine months ended September 30, 2024, compared to $72.6 million during the nine months ended September 30, 2023.