1

 Below -50 F  

Below -45.6 C

2a

-50 to -45 F  

-42.8 to -45.5 C

2b

-45 to -40 F

-40.0 to -42.7 C

3a

-40 to -35 F

-37.3 to -39.9 C

3b

-35 to -30 F

-34.5 to -37.2 C

4a

-30 to -25 F

-31.7 to -34.4 C

4b

-25 to -20 F

-28.9 to -31.6 C

5a

-20 to -15 F

-26.2 to -28.8 C

5b

-15 to -10 F

-23.4 to -26.1 C

6a

-10 to -5 F

-20.6 to -23.3 C

6b

-5 to 0 F  

-17.8 to -20.5 C

7a

0 to 5 F

-15.0 to -17.7 C

7b

5 to 10 F

-12.3 to -14.9 C

8a 

10 to 15 F

-9.5 to -12.2 C

8b

15 to 20 F

-6.7 to -9.4 C

9a

20 to 25 F

-3.9 to -6.6 C

9b

25 to 30 F

-1.2 to -3.8 C

10a

30 to 35 F

1.6 to -1.1 C

10b

35 to 40 F

4.4 to 1.7 C

11

above 40 F

above 4.5 C