Solar magnetic ux evolution fundamentally drives solar variability, whose atmospheric ef- fects are traditionally assessed through various solar activity proxies. Building upon our previous ndings on strong ux density relationships, we present a comprehensive analysis of daily weak ux densities (WFDs) derived from Solar Dynamic Observatory/Helioseismic Magnetic Imager data, categorized into ve magnetic threshold ranges. We examine their relationships with two key solar activity proxies: MgII index and f10.7 cm. Our statisti- cal analysis, employing Pearson and Spearman's correlations complemented by correlograms, wavelet analysis, and MSSA analysis reveal distinctive patterns in WFD-proxy relationships. Notably, WFDs of 1 to 3 demonstrate robust positive Strong correlations and WFD4 shows moderate correlations with the MgII index with 0 lag, suggesting that the variables WFDs 1-4 and the MgII index appear to exhibit synchronous e ects. Most WFDs show moderate correlations with the activity proxies, except for WFD5 , which displays weak correlations. Wavelet analysis reveals that WFD2 and the MgII index maintain a consistent phase rela- tionship, characterized by coherent rightward-pointing arrows within con dence intervals, while WFD3 shows similar but less consistent phase patterns. Moreover, the MSSA analysis con rms that the WFDs and solar activity proxies have a strong relationship. These nd- ings establish WFD2 as the primary contributor to MgII index variability on solar rotational timescales during the minimum phase, which advances our understanding of solar magnetic ux-proxy relationships.