What is the lowest temperature you have incurred in your area?

-1F  It occurred back in the early 70's before I began keeping weather records.   

15° F (-9.8 C) February 1949

It looks like 18 degrees F is the record coldest temperature here. The coldest temperature I remember was 25. 

At the ranch in Wyoming, -40F , -40C
In Minnesota, -40F, -40C
IN Vienna, -1F,  -18.3C

According to Wikipedia, the coldest temperature ever in the closest city to me was -40°, but it doesn’t have a date or anything.  The coldest temperature I recorded on my back porch thermometer was -41° on the morning of the 30th of January 2019.

The coldest temperature in Buenos Aires was -5°C on 9 July 1918.  The 9th of July is Independence Day in Argentina, but the day is also known for winter weather.  The last snowfall in Buenos Aires was on 9 July 2007.  The last snowfall before that in Buenos Aires was on 9 July 1918.

I didn't live in Buenos Aires during the snowstorm on 9 July 2007.  I was in high school then.  I lived at home with my parents in southern Argentina, where there was no snow but very cold temperatures that night.

In MY area? Well I've been cold enough to have blue tits in my garden.