Forex Seasonality – September 2026: Can EUR/USD Extend its Gains to Three Straight Months?

Historical seasonality analysis indicates that September is typically the second-strongest calendar month for EUR/USD performance. Over the 50-plus years since the end of the Bretton Woods system in 1971, the world's most heavily traded currency pair has registered an average gain of +0.6% during September. In August, the pair climbed 0.7%, defying its typical seasonal weakness despite pulling back from monthly highs. While seasonality offers a bullish historical backdrop for EUR/USD, upcoming central bank policy choices from the European Central Bank and the Federal Reserve will serve as key catalysts, driven by imminent Non-Farm Payrolls and CPI data releases. Elsewhere in foreign exchange markets, GBP/USD and AUD/USD historically face headwinds in September, posting average historical declines of -0.4% and -0.3% respectively. Meanwhile, USD/JPY shows an average historical drop of -0.2% in September, though traders are warned that ongoing currency intervention risks near the 161.00 level and close coordination between the U.S. Treasury and Japanese Ministry of Finance could override seasonal norms.