1. occurring or active during the day rather than at night
2. happening or recurring every day; daily
3. of or relating to a 24-hour period
Usage: technical

Examples

• Owls are nocturnal hunters, while eagles are diurnal predators.
• The diurnal temperature range in the desert can be extreme.
• She follows a diurnal routine, waking at sunrise and sleeping at sunset.
• Many flowers have diurnal rhythms and close at night.
• Diurnal animals are most active during daylight hours.
• The patient's diurnal blood pressure fluctuations were monitored closely.