Should also say this about my friend’s location (Lebanon, Connecticut, USA)
Frost Free Days in Celsius = 170
Frost Free Days in Fahrenheit = 170
(calculated at 32 degrees Fahrenheit or 0 degrees Celsius)
Frost Free Days in Celsius calculated at -2 degrees = appx. 200
Frost Free Days in Fahrenheit calculated at 28 degrees = apprx. 200.
Pecan foliage and buds are killed at around 26 degrees Fahrenheit / -3 Celsius so to get a real close picture of a growing season a person should calculate at both 32 F / 0 C and 28 F / -2 C
Once you know this and combine it with information such as summer heat and if you get some good rains during summer then it’s pretty easy for anyone to come up with if a) you can grow pecans and b) what types/cultivars you should focus on.
Of course the only other piece of information remaining the group does not know is what your soil PH is.
Again, he is growing Mullahy and NC-4 pecan and the nuts are filled and he gets crops @ 500 Cooling Degree Days.
That’s all I can think of now.