Sleet

Some people seem fixated on Inuit people having many words for snow, but English does too! From blizzard to whiteout, with flurries, graupel, and drifts, we have so many words. The one this puzzle’s palindrome lines make me think of is sleet.

Rules:
Normal Irregular Sudoku rules apply. (There are nine regions of nine cells each, but they are not 3x3 squares.)
Cells separated by a chess Knight’s move do not contain the same digit.
Digits an equal number of cells from the center of a palindrome line are the same.
Cells marked with a circle contain an odd digit (1, 3, 5, 7, or 9).

Estimated difficulty: 2.5 out of 5