“Fasting Ramadan in Makkah is equivalent to fasting one thousand months elsewhere.” Is this a saheeh hadith?

Praise
be to Allah

It is not saheeh;
it is a da‘eef (weak) hadith that is not soundly narrated. Rather what is
proven mentions the prayer only; one prayer in al-Masjid al-Haraam is
equivalent to one hundred thousand prayers offered elsewhere, and one prayer
in the Mosque of the Prophet (blessings and peace of Allah be upon him) is
better than a thousand prayers offered elsewhere. As for fasting, there is
no proven report about it, except for a da‘eef hadith which says that it
[fasting Ramadan in Makkah] is better than one hundred thousand elsewhere.
But it is da‘eef (weak). However, righteous deeds have a special virtue when
done in Makkah; fasting, giving charity, reciting adhkaar and other
righteous deeds have a special virtue. But there is no evidence to prove the
degree to which they are better (than righteous deeds done elsewhere), apart
from prayer. End quote.