Which month is earth closest to Mars?

Answer 1

This question can't be answered unless the year is also specified.

You need to give a year since Earth and Mars take different amount of days to obit the sun they do not sync up in the same place year to year.

Answer 2

There is no specific month when Earth is closest to Mars. The distance between Earth and Mars can vary depending on their positions in their respective orbits around the Sun. The closest approach between Earth and Mars occurs approximately every 26 months.