Interest income of $846.7 million for the nine months ended September 30, 2024 on loans and loans held for sale increased $161.9 million, or 24%, compared to the nine months ended September 30, 2023. The average balance of loans, including loans held for sale, during the nine months ended September 30, 2024 increased $2.2 billion, or 18%, to $14.2 billion compared to $12.0 billion for the nine months ended September 30, 2023, and the average yield on loans increased 36 basis points, to 7.99% for the nine months ended September 30, 2024, compared to 7.63% for the nine months ended September 30, 2023.
Interest income of $44.0 million for the nine months ended September 30, 2024 on securities available for sale increased $30.0 million, or 214%, compared to the nine months ended September 30, 2023. The average balance of securities available for sale increased $452.6 million, or 76%, to $1.0 billion for the nine months ended September 30, 2024 compared to $592.5 million for the nine months ended September 30, 2023, and the average yield increased 247 basis points, to 5.63% for the nine months ended September 30, 2024, compared to 3.16% for the nine months ended September 30, 2023.
Interest income of $62.4 million for the nine months ended September 30, 2024 on securities held to maturity increased $11.9 million, or 24%, compared to $50.5 million for the nine months ended September 30, 2023. The average balance of securities held to maturity, during the nine months ended September 30, 2024 increased $132.9 million, or 12%, to $1.2 billion compared to the nine months ended September 30, 2023. The average yield on securities held to maturity increased 62 basis points, to 6.86% for the nine months ended September 30, 2024 ended, compared to 6.24% for the nine months ended September 30, 2023.
Interest income of $19.4 million for the nine months ended September 30, 2024 on interest-earning deposits and other interest or dividends increased $10.0 million, or 106%, compared to the nine months ended September 30, 2023. The average balance of interest-earning deposits and other increased $191.8 million, or 83%, to $423.3 million for the nine months ended September 30, 2024, from $231.5 million for the nine months ended September 30, 2023, and the average yield increased 68 basis points, to 6.13% for the nine months ended September 30, 2024, compared to 5.45% for the nine months ended September 30, 2023.
Interest Expense. Total interest expense of $593.4 million for the nine months ended September 30, 2024 increased $151.1 million, or 34%, compared to $442.3 million for the nine months ended September 30, 2023. The higher interest expense reflected increases in both deposits and borrowings, with a shift towards higher collateralized borrowings that has become a more cost-effective option that utilizing brokered deposits.
Interest expense on deposits increased $111.2 million, or 27%, to $516.3 million for the nine months ended September 30, 2024, compared to $405.1 million for the nine months ended September 30, 2023. The increase was primarily due to higher average balances and higher rates for certificate of deposit accounts and interest-bearing checking accounts, as well as higher rates on money market accounts.
Interest expense of $234.0 million for the nine months ended September 30, 2024 for certificates of deposits increased $69.7 million, or 42%, compared to $164.3 million for the nine months ended September 30, 2023. The average balance of certificates of deposit accounts was $5.8 billion for the nine months ended September 30, 2024, an increase of $1.3 billion, or 29%, compared to the nine months ended September 30, 2023. The average rate on certificates of deposit accounts was 5.43% for the nine months ended September 30, 2024, which was a 49 basis point increase compared to 4.94% for the nine months ended September 30, 2023.
Interest expense of $181.4 million for the nine months ended September 30, 2024 for interest-bearing checking accounts increased $33.8 million, or 23%, compared to $147.6 million for the nine months ended September 30, 2023. The average balance of interest-bearing checking accounts of $5.1 billion for the nine months ended September 30, 2024 increased $684.6 million, or 15%, compared to $4.4 billion for the nine months ended September 30, 2023. The average rate on interest-bearing checking accounts was 4.75% for the nine months ended September 30, 2024, which was a 28 basis point increase compared to 4.47% for the nine months ended September 30, 2023.