Diurnal cycle

[1] Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as weather changes throughout the year.

[1] Diurnal cycles may be approximately sinusoidal or include components of a truncated sinusoid (due to the Sun's rising and setting) and thermal relaxation (Newton cooling) at night.

[1] The diurnal cycle also has a great impact on carbon dioxide levels in the atmosphere, due to processes such as photosynthesis and cellular respiration.

[5] A semi-diurnal cycle refers to a pattern that occurs about every twelve hours or about twice a day.

Often these can be related to lunar tides, in which case the interval is closer to 12 hours and 25 minutes.

Earth's rotation relative to the Sun causes the 24-hour day/night cycle.
Diurnal variation of air temperature (blue) lag by 3 to 4 hours behind insolation at solar noon (red).
There are typically three different types of tides: diurnal, which has one high tide and one low tide each day; semi-diurnal, which has two high tides and one low tide each day; and mixed, which has two high tides and two low tides each day with varying heights.
Map of areas with the different tidal cycles.