Brightness temperature RMS as a function of frequency and astrophysical component for temperature. Each component is smoothed to an angular resolution of 1° FWHM, and the lower and upper edges of each band are defined by masks covering 27 and 88% of the sky, respectively. We note that foreground RMS values decrease nearly monotonically with sky fraction, whereas the CMB RMS is independent of sky fraction, up to random variations. The vertical bands represent the frequency range of detector data, where the top panel shows the data employed in this paper and the bottom panel shows some data available for future analysis.