The 12-month Euribor's monthly average reached 3.247% in September, its highest since July 2024 and its third consecutive monthly increase. The daily rate hit 3.379% on September 25, also its highest since July 2024. The Banco de España still has to confirm the monthly average, while variable-rate borrowers face higher instalments at their next review.
August's average was 2.954%. The annual comparison is worse for borrowers.
In September 2025, the Euribor stood at 2.172%. On a €150,000 mortgage over 25 years with an interest rate set at Euribor plus 1%, yearly repayments will rise by more than €1,000. For a €300,000 loan under the same terms, the extra annual cost could reach €2,100.
EFE reported that the benchmark also moved above 3% on a daily basis in August. That had not happened since September 2024. September continued the rise seen in August instead of reversing it.
The report identifies the European Central Bank's decision on September 10 as the immediate trigger. The ECB raised rates by 25 basis points, its second increase of the year. In its official communication, the bank linked the decision to its aim of bringing inflation back to its 2% medium-term target.
Kelisto analysts say the Euribor rise reflects more than that decision. Markets have also raised their expectations for how high rates may go and how long they may stay high while inflation remains under control. The ECB's three basic rates are now 2.50% for the deposit facility, 2.65% for basic refinancing operations and 2.90% for the marginal lending facility.
Spain's inflation rate has added to that pressure. The analysis, citing Spain's National Statistics Institute (INE), puts the consumer price index at 4.9% in September. Kelisto also points to higher bond yields as investors reassess the likely path of interest rates. Energy risks have added to expectations that borrowing costs may stay high for longer.
The year-end forecast depends heavily on inflation and energy prices. Kelisto expects the Euribor to finish the year between 3.1% and 3.3% if energy prices ease. If inflation remains higher than expected and the ECB raises rates again, the estimate rises to 3.4%.
HelpMyCash mortgage analyst Miquel Riera links the September increase to the return of inflation and the possibility of another ECB move. He also says the conflict in the Middle East could affect the benchmark in the coming months. HelpMyCash gives a lower estimate near 2.8% if tensions ease. Its higher scenario puts the rate around 3.5% or above if inflationary pressure continues and rates rise again.
The Euribor now sits 1.075 percentage points above its level a year earlier. That difference can add more than €1,000 to annual payments on a €150,000 mortgage. The increase reaches €2,100 a year on a €300,000 loan. Existing fixed-rate borrowers do not face a direct Euribor adjustment until their fixed period ends. New mortgages and refinancing are already becoming more expensive.
The change now spans more than a month. Three consecutive increases and a September average of 3.247% point to a wider shift in expectations for inflation and interest rates. Unless price pressures ease or the ECB changes course, households with variable-rate loans will carry most of the burden.
