<p>Water on the surface of the Moon is a key factor in tracing lunar surface processes and represents a potential future resource for lunar exploration. Samples from the Apollo and Luna missions provide constraints on the content and possible origin of this water, but represent only low latitudes on the Moon’s nearside. Information about the lunar farside has been restricted to remote sensing observations and thus the global distribution and origin of lunar surface water are still debated. Here we performed laboratory analyses of samples from the lunar farside at mid-latitudes returned by the Chang’e-6 mission. We find that the samples have very low δD values (as low as −983‰) and high water contents (up to 1.7 wt%) in the topmost layers of grains, indicating that solar-wind implantation is the primary source. The water contents are comparable to those reported for Chang’e-5 samples from mid-latitudes on the nearside, but nearly double those of Apollo samples. Infrared reflectance spectra further reveal that the bulk Chang’e-6 samples exhibit stronger OH/H₂O features and higher maturity than Chang’e-5 samples, despite both showing similar water content profiles with depth. These findings suggest that the distribution of water on the lunar surface is strongly dependent on latitude, with the bulk water content also depending on regolith maturity. Our findings imply that lunar surface water may be more abundant in highly mature regolith in high-latitude regions.</p>