Fine mode aerosol optical properties were retrieved from sunphotometer measurements, carried out in Shenyang, Anshan, Benxi, and Fushun in Northeast China from 2009–2013. Accumulation mode aerosol size distribution retrievals were investigated for specific situations involving extensive cloud processing during fog or haze. Large fine mode median radii (≥ 0.20 µm) frequently occurred at the four sites in July. At other times, as aerosol optical depths increased so did the fine mode median radii, reaching 0.30–0.40 µm. This was possibly due to aerosol humidification during cloud processing. Instances of large (~1.50) Alpha curvature at the sites also may be associated with cloud processing. When single scattering albedos were ≥ 0.90, the radii distributions were centered round 0.30–0.40 µm at all at sites except Benxi, perhaps due to non-absorbing material from aerosol/cloud interactions. Case studies of size distribution retrievals at each of the four sites showed that large accumulation mode radii (0.40–0.50 µm) may be linked to cloud processing.