diurnal

Everyday

1. (science) Active during the day and resting at night, like most birds, butterflies and humans. tree →
2. (science) Happening every day, or during the day: «diurnal temperature changes». tree →

In the lessons

In science lessons animals are sorted into diurnal (day-active), nocturnal (night-active) and crepuscular (active at dawn and dusk). In geography, «diurnal range» is the difference between the highest and lowest temperature in one day. Phrases: «diurnal animals», «diurnal range», «diurnal cycle».

Examples

• Squirrels are diurnal, but owls are nocturnal. tree →
• Humans are diurnal animals. tree →
• Most butterflies are diurnal. tree →
• The desert has a large diurnal temperature range. tree →
• The kookaburra is diurnal and laughs at dawn. tree →
• (science) The diurnal cycle of light and dark controls when flowers open. tree →

Note

Opposite: «nocturnal». Pronounced «dye-ER-nal». In maths and geography: if the hottest temperature today is 31 °C and the coldest 12 °C, the diurnal range is 31 − 12 = 19 degrees.