Frost Series by RD Wingfield

These are the books that the television series A Touch of Frost is based on starring David Jason

1.  Frost at Christmas
2.  A Touch of Frost
3.  Night Frost
4.  Hard Frost
5.  Winter Frost
6.  A Killing Frost

After RD Wingfield died in 2007, three further Frost books were published under the name James Henry.

7.  First Frost
8.  Fatal Frost
9.  Morning Frost

I am currently reading Night Frost and am really enjoying these books but I wonder whether the last three will be as good.