No, it isn't "windshield" temperature.

It is "wind chill" temperature which factored into account temperature, moisture, and of course - wind speed.  Or, rather, it WAS called "wind chill" when it came to warnings.

As with many things from our past being canceled, add another one to the list here.
Now, instead of wind chill temperatures, the National Weather Service has added new designations for cold.

Here they are:

• Extreme Cold Warning: Take Action! An Extreme Cold Warning is issued when dangerously cold air temperatures or wind chill values are expected or occurring. If you are in an area with an Extreme Cold Warning, avoid going outside. If you have to go outside, dress in layers, cover exposed skin, and make sure at least one other person knows your whereabouts. Update them when you arrive safely at your destination.  This is a wind chill OR temperature of -25 degrees F in the next 24 to 72 hours.
  
  
• Extreme Cold Watch: Be Prepared. An Extreme Cold Watch is issued when dangerously cold air temperatures or wind chill values are possible. As with a Warning, adjust your plans to avoid being outside during the coldest parts of the day. Make sure your car has at least half a tank of gas, and update your winter survival kit.  This is a wind chill OR temperature of -25 degrees F in the next 12 to 36 hours.
  
  
• Cold Weather Advisory: Be Aware. A Cold Weather Advisory is issued when seasonably cold air temperatures or wind chill values, but not extremely cold values, are expected or occurring. Be sure you and your loved ones dress appropriately and cover exposed skin when venturing outdoors.  This is a wind chill OR temperature of -15 degrees F in the next 12 to 36 hours.

Here's a link to a calculator and warning updates:

https://www.weather.gov/safety/cold-wind-chill-chart