I remember my high school chemistry teacher stating that water could sublime under normal atmospheric conditions that would exist in e.g., Lancaster County, PA, where Amish would hang clothes to dry in the winter in below-freezing temperatures. I do not remember a similar discussion in my physical chemistry (thermodynamics) class in college, but the former example stuck with me. If clothes do indeed sublime water at ca. 1 atm then that means there exists a vapor pressure of water (i.e., ice) below 0 °C at ca. 1 atm.
In looking into this, the USGS states that, "It is not easy to actually see sublimation occurring, at least not with ice. One way to see the results of sublimation is to hang a wet shirt outside on a below-freezing day. Eventually the ice in the shirt will disappear."
Yet, when I look at the phase diagram, there is no path from solid to vapor at any temperature below 0 °C that is also anywhere near 1 atm. The highest pressure at which a phase boundary exists between solid and gas is 612 Pa, or 0.006 atm.
The USGS article goes on to discuss the south face of Everest and the Chinook winds sublimating snow and ice suggesting that it does indeed occur, though at admittedly much higher elevations (and lower pressure) than e.g., Lancaster, PA, but these are nowhere near the pressures you would have in e.g., lyophilizers I've used.
The only way I can come up with an explanation is if the "pressure" in the above phase diagram is somehow influenced by the partial pressure of water (i.e., "humidity") as opposed to or in addition to the net pressure of the system in total.
So the question is, if you are above 0.006 atm but somewhere between −60 °C and 0 °C where a phase boundary does not exist between solid and vapor/gas, how can water sublimate at ca. 1 atm in the example of drying frozen laundry? Additionally, is there a partial pressure of water at, e.g., −10 °C and 1 atm?
In partial answer to the latter question, this link shows vapor partial pressures down to −82 °C and seems to indicate that those partial pressures are irrespective of the net pressure of the system ("...if the pressure in the chamber exceeds the vapor pressure of the product while in the presence of ice, water may not be able to sublime.").