U.S. retail sales posted a surprise jump in September, extending back-to-back monthly gains as coronavirus pandemic pressures on consumer spending driven by the Delta variant begin to ease.

Total retail sales increased by 0.7% in September over August, the U.S. Commerce Department said in its monthly report Friday. Last month's total followed a 0.9% rise in August, which was upwardly revised from the 0.7% increase reported prior. Over last year, retail sales jumped by 13.9%.

September's rise also boosted retail-focused exchange-traded funds (ETF), including SPDR S&P Retail ETF (XRT  ) and VanEck Retail ETF (RTH  ), both rising about 1.3% and 1.4%, respectively, following the data release.

"Wall Street was expecting a slowdown in spending, but it turns out the U.S. consumer is not to be messed with. Back-to-back months of better-than-expected retail sales data shows the consumer looks strong heading into the holiday season," said Edward Moya, senior market analyst of The Americas at OANDA, in a statement.

"Retail sales might moderate next month, but early holiday is happening and Americans seem poised to spend big this holiday season," Moya added. "With supply chain issues nudging people to shop early and with Chanukah starting late November, retail sales should remain robust going into year end."

Beneath the headline, increases in retail sales were board across multiple industries, with sporting goods, hobby, and musical instrument and book stores leading gains by a 3.7% month-over-month rise in September. Moreover, general merchandise store sales climbed by 2%, miscellaneous store retailers gained by 1.8%, gasoline station sales increased by 1.8%, non-store retailers, or e-commerce platforms, bumped up 0.6% higher, and motor vehicle and parts dealer sales increased by 0.5%.

Meanwhile, categories associated with U.S. economic reopening also rose in September compared to August, with food services and drinking places sales increasing by 0.3%, while clothing and clothing accessory store sales gained by 1.1%.