<p><strong>The latitudes today are 66°33′46.1″ N and S, the Arctic and Antarctic Circles.</strong></p>

<p>By definition, north of the <a href="https://en.wikipedia.org/wiki/Arctic_Circle" rel="noreferrer">Arctic circle</a>, and south of the Antarctic circle, everywhere gets at least one day with no sunset, which I guess is what you mean by 'exactly 24 hours of daylight'? </p>

<p>From the linked article: </p>

<blockquote>
  <p>North of the Arctic Circle, the sun is above the horizon for 24 continuous hours at least once per year (and therefore visible at midnight) and below the horizon for 24 continuous hours at least once per year (and therefore not visible at noon).</p>
</blockquote>

CC BY-SA 3.0
2016-02-05T18:05:16.783Z
You can interpret "exactly 24 hours of daylight" however you like. I thought the simplest interpretation was the one that defines the famous Circles.
Matt Hall
CC BY-SA 4.0
2019-10-23T08:29:24.803Z
@kwinkunks, the Arctic circle and the Tropic lines are generated due to the Sun transit. It is not related to the duration of the sunlight. Atmospheric refraction and reflexion allow us to see the Sun around 3º under their position on the sunset and sunrise. So when you think that the Sun is in the horizon, it is under it.
David García Bodego
CC BY-SA 4.0
2021-11-09T22:45:31.447Z
Subtract a few arc minutes south from the Arctic Circle / north from the Antarctic Circle -- the Sun's disk is about 30 minutes across.
Spencer
CC BY-SA 3.0
2016-02-05T11:10:39.430Z
2016-02-05T18:04:32.513Z
2016-02-05T18:04:32.513Z
Matt Hall
<p>It depends...</p>

<p>What do you understand as 24 hours daylight? Sun should be visible? There should be light, even if the Sun is not visible?</p>

<p>There are different interpretations:</p>

<p>Astronomical Twilight:Astronomical twilight is the darkest of the 3 twilight phases. It is the earliest stage of dawn in the morning and the last stage of dusk in the evening.</p>

<p>Nautical Twilight: Nautical twilight is the second twilight phase. Both the horizon and the brighter stars are usually visible at this time, making it possible to navigate at sea.</p>

<p>Civil Twilight: Civil twilight is the brightest of the 3 twilight phases. The Sun is just below the horizon, so there is generally enough natural light to carry out most outdoor activities</p>

<p>So if you consider the Civil twilight, at 61º lattitude, you will get one 24 hours daylight. (Close to Helsinki - Finland)</p>

<p>If you go to the Nautical one, then you will come south.</p>

<p>Check this <a href="https://www.timeanddate.com/sun/finland/helsinki" rel="nofollow noreferrer">link</a>. You will enjoy.</p>

<p>Hope it helps!</p>

CC BY-SA 4.0
2019-10-23T08:24:28.927Z
2019-10-23T08:24:28.927Z
David García Bodego
<p>I believe the phrase <em>specific words  have specific meaning</em> is pertinent here. I believe the question has been misunderstood in the answers as pertaining to daylight instead of daytime. This question is not referring to daylight hours, it is in reference to the fact that the sidereal day length varies by plus or minus ~4 minutes due to a few factors; asynchronous rotation of earth, earth's tilted axis, variable speed at para/aphelion positions, and elliptical orbit being the primary factors. The 24hr day we all use is the sidereal mean time or standard time.</p>
<p>It is an interesting question. I cannot purport that the following is absolutely a fact but would say that it is a reasonable presumption with high confidence.</p>
<p>It would likely be between the 23.5 degree latitudes known as the tropic of Cancer and Capricorn. I might even make the assumption that you would have to be one that latitude in conjunction with the corresponding equinox or solstice. Those assumptions are hesitant at best though. The lack of data published makes me consider that the interactions of celestial bodies in asynchronous and non tidally locked orbits, while also wobbling on axis may continually affect what days and latitudes the amount of time from apex to apex of the sun to be exactly 24 hrs.</p>

CC BY-SA 4.0
2021-11-09T23:51:34.827Z
Fair point, but the OP mentions both 'daylight' and 'daytime' so at best it's ambiguous. I agree your question is arguably more interesting, though I think it's the solar (not sidereal) day that varies in the way you're describing. A function with the awesome name ['the equation of time'](https://en.wikipedia.org/wiki/Equation_of_time) crosses the x-axis — denoting a solar day of exactly 24 hours — four times a year for a given location.
Matt Hall
CC BY-SA 4.0
2021-11-10T08:42:46.080Z
This question would probably be best answered at Astronomy SE.
Jean-Marie Prival
CC BY-SA 4.0
2021-11-10T18:23:18.633Z
In addition to @kwinkunks comment, a 24.0000000 hour day as determined by the equation of time is independent of the latitude. This contradicts the OP which definitely asks for the latitude. It seems the OP is not asking for the date when the solar day is closest to being 24 hours long.
JohnHoltz
CC BY-SA 4.0
2021-11-09T22:22:23.550Z
2021-11-09T22:22:23.550Z
Jefferson Davis
<p>I assume at the Solstice - a definite latitude would have exactly 24 hours of daylight. What latitudes (North and South) are these - they might vary a little with longitude? </p>

<earth-observation>
At what latitudes does daytime last exactly 24 hours once in the year?
user2617804
# At what latitudes does daytime last exactly 24 hours once in the year?

(Asked by: username_0 on 2016-02-05)

I assume at the Solstice - a definite latitude would have exactly 24 hours of daylight. What latitudes (North and South) are these - they might vary a little with longitude?

**Tags:** earth-observation


---

## 3 answers

### Answer by username_1 on 2016-02-05. Score: 9

**The latitudes today are 66°33′46.1″ N and S, the Arctic and Antarctic Circles.**

By definition, north of the [Arctic circle](https://en.wikipedia.org/wiki/Arctic_Circle), and south of the Antarctic circle, everywhere gets at least one day with no sunset, which I guess is what you mean by 'exactly 24 hours of daylight'?

From the linked article:

> North of the Arctic Circle, the sun is above the horizon for 24 continuous hours at least once per year (and therefore visible at midnight) and below the horizon for 24 continuous hours at least once per year (and therefore not visible at noon).

> **Comments:**
> **username_1**: You can interpret "exactly 24 hours of daylight" however you like. I thought the simplest interpretation was the one that defines the famous Circles.  
> **username_2**: @kwinkunks, the Arctic circle and the Tropic lines are generated due to the Sun transit. It is not related to the duration of the sunlight. Atmospheric refraction and reflexion allow us to see the Sun around 3º under their position on the sunset and sunrise. So when you think that the Sun is in the horizon, it is under it.  
> **username_3**: Subtract a few arc minutes south from the Arctic Circle / north from the Antarctic Circle -- the Sun's disk is about 30 minutes across.  

---

### Answer by username_2 on 2019-10-23. Score: 2

It depends...

What do you understand as 24 hours daylight? Sun should be visible? There should be light, even if the Sun is not visible?

There are different interpretations:

Astronomical Twilight:Astronomical twilight is the darkest of the 3 twilight phases. It is the earliest stage of dawn in the morning and the last stage of dusk in the evening.

Nautical Twilight: Nautical twilight is the second twilight phase. Both the horizon and the brighter stars are usually visible at this time, making it possible to navigate at sea.

Civil Twilight: Civil twilight is the brightest of the 3 twilight phases. The Sun is just below the horizon, so there is generally enough natural light to carry out most outdoor activities

So if you consider the Civil twilight, at 61º lattitude, you will get one 24 hours daylight. (Close to Helsinki - Finland)

If you go to the Nautical one, then you will come south.

Check this [link](https://www.timeanddate.com/sun/finland/helsinki). You will enjoy.

Hope it helps!


---

### Answer by username_4 on 2021-11-09. Score: 0

I believe the phrase *specific words have specific meaning* is pertinent here. I believe the question has been misunderstood in the answers as pertaining to daylight instead of daytime. This question is not referring to daylight hours, it is in reference to the fact that the sidereal day length varies by plus or minus ~4 minutes due to a few factors; asynchronous rotation of earth, earth's tilted axis, variable speed at para/aphelion positions, and elliptical orbit being the primary factors. The 24hr day we all use is the sidereal mean time or standard time.

It is an interesting question. I cannot purport that the following is absolutely a fact but would say that it is a reasonable presumption with high confidence.

It would likely be between the 23.5 degree latitudes known as the tropic of Cancer and Capricorn. I might even make the assumption that you would have to be one that latitude in conjunction with the corresponding equinox or solstice. Those assumptions are hesitant at best though. The lack of data published makes me consider that the interactions of celestial bodies in asynchronous and non tidally locked orbits, while also wobbling on axis may continually affect what days and latitudes the amount of time from apex to apex of the sun to be exactly 24 hrs.

> **Comments:**
> **username_1**: Fair point, but the OP mentions both 'daylight' and 'daytime' so at best it's ambiguous. I agree your question is arguably more interesting, though I think it's the solar (not sidereal) day that varies in the way you're describing. A function with the awesome name ['the equation of time'](https://en.wikipedia.org/wiki/Equation_of_time) crosses the x-axis — denoting a solar day of exactly 24 hours — four times a year for a given location.  
> **username_5**: This question would probably be best answered at Astronomy SE.  
> **username_6**: In addition to @kwinkunks comment, a 24.0000000 hour day as determined by the equation of time is independent of the latitude. This contradicts the OP which definitely asks for the latitude. It seems the OP is not asking for the date when the solar day is closest to being 24 hours long.  

---

