The restaurant industry's monthly same-store sales growth rate rose at an all-time-high in December, fueled by sharp gains in guest traffic and cooperative weather, according to the latest NRN-MillerPulse survey.

Industrywide same-store sales rose 5.4 percent in December, compared with a 2.9-percent increase the month prior, which is the largest increase in the survey’s history. The month capped off a relatively strong 2011 that saw same-store sales up 2.6 percent overall, leaving operators and analysts pleasantly surprised.

“December was a win across the board,” said Larry Miller, restaurant securities analyst at RBC Capital Markets in Atlanta and creator of the monthly MillerPulse surveys and research. “This could be the first sign of the rising tide that we’ve been waiting to see.”

MillerPulse, an operator survey exclusive to Nation’s Restaurant News, polled around 70 restaurant operators in January regarding December sales, profit trends, performance and outlooks. Respondents cover all regions of the country and represent the quick-service, casual-dining, fine-dining and fast-casual segments. Those surveyed in January represented restaurants that booked about 4 percent of industry sales.

Both the quick-service and full-service segments posted record-setting increases in same-store sales, the survey found. Sales at quick-service restaurants, which include both fast-food and fast-casual brands, rose 6.7 percent in December, compared with a 4-percent increase November. Sales for full-service restaurants, which include both fine-dining and casual-dining brands, increased 4.2 percent in December, compared with a 2-percent increase in the prior month.

The substantial sales increases were largely driven by guest traffic gains, which rose nearly 3 percent in December, compared to being relatively flat in November. Quick-service traffic jumped 4.2 percent in December, compared to just over a 1-percent increase in November, while full-service traffic rose 1.7 percent after seeing a 1.1-percent decline in November.