This wiki contains plots of sky brightness for January and February 2010. The selection was for exposures > 25s long, things that were not DARK or FLAT, with a background > 0 and from ota 33.

There are no other cuts.

The calculation for sky brightness assumes a bias of 7794, which is reasonable for chip 33, and uses E. Schafly's zero points.

The colors are as follows:

g = green
r = red
i = blue
z = cyan
y = purple