Along with the 10 min period knowledge, it's also helpful to know that many machines carry their rating at 104°F.
So at lower ambient temps, the duty cycle goes up.
From ESAB while referencing a 40% duty cycle at 285 amps:
"We evaluate duty cycle at a specific ambient temperature葉ypically 104 F. In cooler ambient temperatures, duty cycle increases. For example, when welding at 70 F, you could experience close to a 100-percent duty cycle耀pecifics will vary by machine and actual parameters, but welding in cooler temperatures definitely boosts duty cycle."