The data is collected at 00:00 UTC and 12:00 UTC of each day. For Tucson, AZ, (UTC -7:00) that corresponds to 5:00 pm and 5:00 am respectively ... ignoring daylight savings time. Surface temperatures Morning Afternoon C F C F 02-15 7.8 46.0 26.7 80.1 05-15 18.3 64.9 37.2 99.0 08-14 23.9 75.0 36.7 98.1