Check out these super cold records, copper and PVC pipes can crack and break at these temps.
We get asked a bunch should we winterize the sprinklers in early October, Yes is the short answer.
Commercial properties are usually shutting down the last week of September.

October              
Date   Low/Year          Snow    
1   24/1974          
2   22/1974          
3   26/1996       T/1935    
4   24/1935       T/1935    
5   25/1952       T/1991*    
6   25/1873       T/1952    
7   25/1976       T/1977*    
8   23/1876       0.3/1959    
9   22/1895       0.5/1925    
10   25/1987*       2.5/1977    
11   22/1876       0.5/1977    
12   23/1917       2.5/2009    
13   22/1917       T/1955*    
14   24/1937       0.3/2018    
15   21/1876       0.3/1992    
16   23/1952       0.5/1992    
17   22/1952*       T/1990*    
18   18/1972       1.3/1976    
19   15/1972       1.3/1916    
20   18/1960       3.0/1916    
21   16/1913       0.1/1936   Most Snow
22   20/1936       1.0/1925   8.2/1991
23   17/1936       1.4/1938    
24   15/1887       1.0/2001    
25   12/1887       0.4/2001   Least Snow
26   16/1962       1.3/1959   0.0 (Many
27   13/1997       2.6/1919   Years)
28   17/1925*       0.4/1895    
29   15/1925       5.5/1905    
30   10/1925       0.8/1951    
31   15/1878       8.2/1991    
Period of Record: 1871-Present