Another cold front passed through Arizona during the day, which dropped temperatures further and produced a few drops of rain in the late afternoon. What clouds were left at sunset dissipated during evening twilight. The front can be seen on the far right of the midnight IR image (in central New Mexico). The night was clear and even colder than the previous two nights. The seeing was poor (2-2.5 arcsec) during the first half of the night. During the remainder of the night, the seeing improved to 1.4-2 arcsec.