daylength
Hours of sunlight
Daylength is the duration of daylight in a given day, varying by latitude and season.
The term appears most often in discussions of biology and agriculture, where daylength affects plant flowering, animal behavior, and migration patterns: Some plants won't bloom unless daylength exceeds twelve hours.
Also spelled as two words: day length.
Recoiling metal spiral
- summerYear's warmest season
- autumnPost-summer cooling period
- winterYear's coldest quarter
- solsticeDay of maximum tilt
equinox · vernal · autumnal · hibernal · midsummer · midwinter · shortening · seasonal variation
Morning light's arrival
- sunsetDay yielding to darkness
- dawnDay's first glow
- duskDimming after sundown
- twilightLight after sunset
solar noon · zenith · horizon · diurnal · rotation · orbit · sidereal · synodic
Producing reproductive structures
- circadianDaily biological cycle
- biological clockInnate cycle regulator
- photoreceptorCell responding to light
- dormancySuspended biological activity
germination · budbreak · bolting · melatonin · diapause · entrainment · photophile
Midpoint circle of rotation
- tropicWarm Earth zone
- arcticOf extreme northern cold
- polarOf extreme latitudes
- temperateMild, avoiding extremes
subtropical · tropical · hemisphere · midnight sun · polar night · white nights · high latitude · geographic variation
Sixty-minute spans
- minutesSixty-second intervals
- sunset timeWhen the sun disappears
- solar calculatorBattery-free computing device
- almanacYearly data compilation
photometer · light meter · lux · duration
spring
Recoiling metal spiral
solstice · equinox · vernal · autumnal · hibernal · midsummer · midwinter · shortening · seasonal variation · annual cycle
sunrise
Morning light's arrival
twilight · solar noon · zenith · horizon · diurnal · rotation · orbit · sidereal · synodic · solar
flowering
Producing reproductive structures
- circadianDaily biological cycle
- biological clockInnate cycle regulator
- photoreceptorCell responding to light
dormancy · germination · budbreak · bolting · melatonin · diapause · entrainment · photophile
equator
Midpoint circle of rotation
temperate · subtropical · tropical · hemisphere · midnight sun · polar night · white nights · high latitude · geographic variation · north
hours
Sixty-minute spans
- minutesSixty-second intervals
- sunset timeWhen the sun disappears
- solar calculatorBattery-free computing device
almanac · photometer · light meter · lux · duration
- agroclimategrowing season, frost date, frost dates, evapotranspiration, soil moisture
- plant timingbloom, phenology, spring bloom, summer bloom, seasonal bloom