We observed squeezed vacuum light at $795\mathrm{nm}$ in ${}^{87}\mathrm{Rb}$ vapor via resonant polarization self-rotation and report noise sidebands suppression of $\approx 1\mathrm{dB}$ below shot-noise level spanning from $30\mathrm{kHz}$ to $1.2\mathrm{MHz}$ frequencies. To our knowledge, this is the first demonstration of submegahertz quadrature vacuum squeezing in atomic systems. The spectral range of observed squeezing matches well typical bandwidths of electromagnetically induced transparency (EIT) resonances, making this simple technique for generation of optical fields with nonclassical statistics at atomic transitions wavelengths attractive for EIT-based quantum information protocols applications.