di·ur·nal
dī-ˈər-nᵊl 
1
a
biology
: active chiefly in the daytime
diurnal animals
b
: of, relating to, or occurring in the daytime
the city's diurnal noises
c
botany
: opening during the day and closing at night
diurnal flowers
2
a
: recurring every day
diurnal tasks
b
: having a daily cycle
diurnal tides
1
Synonyms
Examples of diurnal in a Sentence
Adjective
a love as constant and certain as the diurnal tides
Noun
a collection of diurnals containing essays by preeminent 19th-century American writers and thinkers
Recent Examples on the Web
Carlyn Kranking, Smithsonian Magazine, 5 Apr. 2024
The diurnal asymmetric warming of the earth has reversed course since 1991, with daytime temperatures rising faster than nighttime ones.
—Frederick Kaufman, Harper's Magazine, 26 Feb. 2024
But where owls have evolved to overcome darkness, the diurnal raptors excel at overcoming distance, the second great limit to our vision.
—Jack Gedney, The Mercury News, 11 Mar. 2024
One question researchers want to answer is whether nocturnal and diurnal animals act differently or become more or less vocal during a solar eclipse.
—Jamie Carter, Forbes, 13 Feb. 2024
The question of whether dinosaurs were nocturnal (active at night) or diurnal (active during the day) is complex, as dinosaurs were a highly diverse group of animals.
—Sara Novak, Discover Magazine, 14 Dec. 2023
That, along with a good diurnal shift in temperature, helps keep the wine fresh.
—Lana Bortolot, Forbes, 30 Nov. 2023
The most significant shift was in cheetahs, a typically diurnal species -- or one that spends its awake hours during the day -- the researchers said.
—Julia Jacobo, ABC News, 7 Nov. 2023
How Do Frogs See? Scientists from the Natural History Museum, have discovered a connection between frogs that are active during the day (diurnal frogs) and the development of lenses in their eyes.
—Katie Liu, Discover Magazine, 26 Oct. 2023
Adjective
Frogs and crickets, common elements of an evening soundscape, started to call, while diurnal cicadas stopped making noise.
—Carlyn Kranking, Smithsonian Magazine, 5 Apr. 2024
The diurnal asymmetric warming of the earth has reversed course since 1991, with daytime temperatures rising faster than nighttime ones.
—Frederick Kaufman, Harper's Magazine, 26 Feb. 2024
But where owls have evolved to overcome darkness, the diurnal raptors excel at overcoming distance, the second great limit to our vision.
—Jack Gedney, The Mercury News, 11 Mar. 2024
One question researchers want to answer is whether nocturnal and diurnal animals act differently or become more or less vocal during a solar eclipse.
—Jamie Carter, Forbes, 13 Feb. 2024
The question of whether dinosaurs were nocturnal (active at night) or diurnal (active during the day) is complex, as dinosaurs were a highly diverse group of animals.
—Sara Novak, Discover Magazine, 14 Dec. 2023
That, along with a good diurnal shift in temperature, helps keep the wine fresh.
—Lana Bortolot, Forbes, 30 Nov. 2023
The most significant shift was in cheetahs, a typically diurnal species -- or one that spends its awake hours during the day -- the researchers said.
—Julia Jacobo, ABC News, 7 Nov. 2023
How Do Frogs See? Scientists from the Natural History Museum, have discovered a connection between frogs that are active during the day (diurnal frogs) and the development of lenses in their eyes.
—Katie Liu, Discover Magazine, 26 Oct. 2023
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'diurnal.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near diurnal
Cite this Entry
“Diurnal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diurnal. Accessed 19 Apr. 2024.
Copy CitationMedical Definition
diurnal
adjective
di·ur·nal
dī-ˈərn-ᵊl
1
: having a daily cycle
diurnal rhythms
2
a
: of, relating to, or occurring in the daytime
diurnal activity
b
: chiefly active during the daytime
diurnal mosquitoes
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