Figure F3. Time of day and watch compared to core liner average temperatures. Nighttime (1800-0700 hr) is shaded. Night watch and day watch are indicated at the top and divided with the dotted line. A. Site 1226. Average daytime core temperature = 18.73° ± 1.26°C, and average nighttime core temperature = 18.05° ± 1.47°C. Average day watch core temperature = 18.50° ± 0.93°C, and average night watch core temperature = 18.28° ± 1.76°C. B. Site 1230. Average daytime core temperature = 18.22° ± 1.46°C, and average nighttime core temperature = 18.29° ± 1.15°C. Average day watch core temperature = 17.88° ± 1.26°C, and average night watch core temperature = 18.59° ± 1.28°C. No sampling bias was found.