The G.A.C. Fat Ass 50K has seen its share of cold, challenging weather conditions during the past 19 years, including a mid-race snowstorm in 2017 that sent some runners home early and forced others to scrape a few inches of fresh powder off of their windshields after finishing.

The forecast for the 20^th annual Fat Ass 50K on Saturday at Bradley Palmer State Park in Topsfield, Mass., looks like a recipe for frostbite, however, with The Weather Channel projecting a high of 4 degrees, a low of minus 9, and 17-mile-per-hour wind. Given the potentially dangerous conditions, the ultramarathon has been called off to ensure the safety of both runners and volunteers.

“Due to expected severe cold weather on January 6^th the GAC Fatass 50 has been canceled,” Roger Martell posted on the G.A.C. website announcing the cancellation.

Although the 50K has been canceled, runners hoping to log a few frigid miles can still take part in a 10K fun run at 9 a.m. that will cover one loop of the race course, Martell also noted.

New England has been buried in frigid temperatures for nearly two weeks. In Boston, the temperature last reached 20 degrees on Dec. 27, and the last time it was above 32 degrees was Dec. 25. The punishing stretch of cold weather is expected to continue with snow on Thursday, followed by a high of 14 degrees and a low of minus 6 on Friday, leading into Saturday’s even more bitter conditions.