Cox Automotive forecasts 1.25 million new-vehicle sales in September 2019, which would represent a 14% drop from the previous year.

One main contributor to this decline was the timing of Labor Day. Labor Day provides a sizeable bump to sales figure and the fact that Labor Day landed in August this year boosted August’s numbers but hurt September’s.

As a result, August became the highest sales volume month of 2019 and the third-highest sales month since 2009. Meanwhile, September’s volume saw a steep drop. The 23 selling days in September, the lowest amount of selling days in four years, also hurt sales.

"Cox Automotive expects sales volume this month to fall to the lowest level since the cold days of February. It will also be the worst September since 2014. However, and importantly, the large volume decline overstates the actual health of the market,” said Cox Automotive Senior Economist Charlie Chesbrough. “The SAAR is expected to reflect a much more stable market. After adjustment, the SAAR is likely to finish at 16.9 million, very close to August's 17.0 million pace. This likely September SAAR suggests a market more stable over the last three months than it was during the first half of the year."

Compact and midsize SUV/crossovers are expected to see the smallest decline in sales through the month. Alternatively, compact cars are expected to see the biggest decline in sales on a year-over-year basis.

In terms of OEMs, Cox Automotive forecasts Nissan North America to experience the biggest sales decline while Subaru is projected to see the smallest decline on a year-over-year basis.