How fast the days are getting longer
87 comments
·March 19, 2025NorwegianDude
It's always interesting how it affects how people think about the day. If you look outside and it's dark then it's easy to think that the day is basically over, even though the time might say otherwise.
I really appreciate the long winter nights and long summer days in Norway. Being able to wake up to the sun as early as 04 and enjoy it until after 23 is great, and the UV is only high during the middle of the day. Long summer days are awesome. Long winter nights are probably not as appreciated, but I enjoy those too.
munificent
Fifteen years ago, I moved from Orlando to Seattle, and almost 20 degree change in latitude. On top of that, Orlando is famously hot and sunny and Seattle famously cold, cloudy, and rainy.
Despite that huge change, I adapted to the new climate just fine. I don't mind the gloom or the cold. The six months of gray skies don't get my down like they do a lot of people.
But even after a decade, I still haven't gotten used to how much the day length changes. Every summer my brain keeps expecting the sun to go down any second now while it sits up there near the horizon giving an extra two hours of daylight. Every winter it feels like the sun disappears too early.
porkloin
I think what's fascinating about it is the daylight changes you experienced in the 20 deg latitude change you experience from Orlando to Seattle are dwarfed by the changes from a ~15 degree latitude change from Seattle to Anchorage. By the time you're getting close to the pole, you can see huge differences in solstice minimum/maximum sunlight by moving just a few hundred miles north or south.
nostromo
Seattle’s climate is a joy.
It’s rarely super hot or super cold like a lot of places.
You get these ridiculously long summer days that last forever. It’s perfect for athletics and hiking and spending time on the water.
And likewise you get these wonderfully wet and dark winters which are perfect for life’s other joys: coding, reading, playing video games, etc.
I love places like San Diego but I wouldn’t want to live in a place that is always a perfect summer day.
connicpu
The downside of the historically mild climate is a lot of older homes weren't built with energy efficiency in mind and now in 2025 we have to deal with that inefficiency on our energy bills :'(
screye
Definitely unpopular opinion.
I love 4 seasons. But the weather and day length make for a difficult half-year from Oct - Mar. The NE corridor has some of these traits, but it was a lot easier to deal with there. In the NE, rain & grey-skies aren't as persistent. In Seattle, a month can go by without seeing the sun.
mikepurvis
I was in Seattle Sept-Dec of 2008 on an internship and I remember feeling some of this. Based on what people had said, I was geared up for four months of a soggy, misty mess, but it wasn't that at all— the autumn there was splendid, with tons of breezy, cool days where the sun still shone, with the trees around my place in Madrona showing brilliant colour for weeks on end.
bombcar
San Diego is months of June Gloom and other Seattle-reminiscent weather, and some sunny days.
Unless you're inland, where it's ninety billion degrees in the shade half the year.
Nice place.
rconti
That's much of the west coast (west of the cascades). I moved from Seattle to the Bay Area, and it's basically the same weather except somewhat shorter summer days and winter nights, WAY more sunshine, and generally about 10f warmer. Except in the summers where these days it seems like Seattle has more 95+ degree days than the peninsula does.
muyuu
It's the same in the UK vs Southern Europe and Japan where I've lived before. People complain about the wet weather, but it's not that IMO what really gets to you, it's the dark winters with so little daylight compounded with the abundance of cloudy days.
Temperature-wise, most of the UK is actually quite moderate compared to central Europe. It's winter darkness that gets to you.
fifilura
To put it in perspective, Paris is further north than Seattle.
porkloin
I live at ~64 deg latitude in the USA (Alaska) and 100% agree with everything you said. The timing of sunset has such a profound effect on when you consider the day "done". In Dec it's painful to haul myself outside at 5 or 6 PM since it's "night time" already. Meanwhile in June, at 11PM/23:00 when it's still bright out I have to remind myself to home and go to bed so I'm not a tired wreck at work the next day :)
intothemild
As someone who moved to Norway. The only thing that's strange to me about the length of day/night... Is that we do daylight savings here.
Why? What help does it make adding one extra hour to the start of the day, when the day lasts like ~4 hours.
latexr
Could be so the time is better synchronised with the rest of Europe, which is relevant for business reasons. I seem to recall reading recently about some other country doing exactly that (though it wasn’t Norway).
kevin_thibedeau
For economic harmony with EU.
MarcelOlsz
I'm trying to find the darkest corner of the earth to chill in so I can actually get some work done. I can't get anything done when the sun is out and people are out and about. Maybe I'll move to that Italian village that has the giant sun mirror thing.
kccqzy
I personally like extremes. My ideal scenario would be a dark room where I can get work done, and then every hour or so, I take a five-minute break outdoors in direct sunlight.
hollerith
I spend most of the day in a fairly dark room, but make sure to get at least 20 minutes of sunlight on my bare skin and eyes every other day -- but it's not because I like extremes: it is because sunlight is good for me, but LED light bulbs are bad for me or at least they are if they are of typical brightness and they are on most of the day.
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keybored
Rjukan, Norway. Dark half the year, cheap real estate and comes with mirrors.
https://www.bbc.com/future/article/20170314-the-town-that-bu...
munificent
Seattle says hi.
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MarcelOlsz
I was under the impression that Seattle was ultra sunny.
bastardoperator
My buddy went to Norway and was super upset because the sun never set in the part of Norway he was staying in and he had no idea it would be daylight almost the majority if not the entire day. He also said his Norwegian family was getting upset with him because he wasn't sleeping and keeping everyone up due to his lack of day/night reference.
jghn
I really struggle with this at daylight savings switches when I work in offices where I can see a window. It takes me a couple of weeks to adjust. In one direction I find I work later than I intended. In the other direction I find myself ready to leave and realize it's only 4:30
dullcrisp
I tend to lean into it, though that’s of course not an option for most people.
jader201
Something that is still crazy to me, regarding time zones, is that my hometown (where my mom lives and we visit frequently) is about 1.5 hours to the west, one timezone over.
When I’m taking to her on the phone in the evening, we’ll be talking about it getting darker.
The difference in the sunset 1.5 hours away in another timezone:
About 9 minutes.
This equates to my evening daylight lasting 51 minutes than hers, and her daylight in the mornings starting 51 minutes before mine (in our respective time zones).
Which seems to negate the whole effects of daylight saving time for one of us.
Of course this is exacerbated even more if you’re across the border of a timezone from each other (which I pretty much live on the western border of ET).
frankus
The whole "6am sunrise and 6pm sunset every day of the year" thing at the equator is kind of mind blowing.
Another maybe counterintuitive fact is that (to a reasonable approximation) everywhere on earth gets the same number of hours of daylight over the course of a year.
infinitifall
Funny because growing up in the tropics I thought sunset and sunrise were synonymous with those times of the day, and learning people in other parts of the world experienced shrinking/lengthening day/night cycles was mind blowing. You mean it's 8PM in the night but the sun's still in the sky?
lars512
When living in Stockholm, I came to appreciate the various levels of twilight and darkness, rather than thinking of day and night so strictly. The sun being low on the horizon also scatters light across the sky in ways that are very beautiful and last much longer than sunrise and sunset in Australia where I grew up.
Zanfa
Having grown up around the same latitude as Stockholm, one thing I never realized until last year when visiting tropics is how my subconscious associates warmth with long evenings. Being used to summers where you could basically read a book outside at 11PM, it felt really weird to be outside in tropic heat, but complete darkness by 6PM.
mdpye
Catches me every time too. And it's so quick. You can go in to a shop to pick up a packet of crisps thinking it's daytime, but actually is quarter past 6, so you come back out and it's full dark!
I'm in the southern UK, and I'd take our late-May/early-August "it's light while I'm awake and dark while I (should be) asleep" all year round if I could get it.
jaggederest
You could become peripatetic and seek out the spot of opposite latitude during the dark season. So you could have 15 hours of daylight, 12 hours of daylight, then 15 hours of daylight again. I've thought that with idle rich amounts of money I'd get a very large yacht and sail the pacific rim in time with the seasons, perpetual spring, summer, spring, summer.
dietr1ch
> When living in Stockholm, I came to appreciate the various levels of twilight and darkness, rather than thinking of day and night so strictly.
In Chile you get somewhat long days and short days too, especially in the south, but instead of trying to be super precise about sunlight, the afternoon and night blend in and sort of crossfade. You end up with "8 de la tarde" (8 in the afternoon), and "6 de la noche" (6 at night) depending on the season.
madcaptenor
Also: https://www.academia.org.mx/consultas/obras-de-consulta-en-l...
7/8/9 de la noche (vs tarde) is used by 60/97/100% of American Spanish speakers vs 1/16/97% of European Spanish speakers. I wonder if the difference is due to Spain's generally late sunsets.
It would be interesting to redo this analysis with a corpus that indicates seasons though.
madcaptenor
I think I have used "8 in the afternoon" even as close to the equator as Atlanta (~34 N). Our latest sunset is 8:52 pm, surprisingly late, because we are very far west in our time zone.
christopher8827
Depends. I lived in St Kilda where the beach faces east. The sunset / golden hour seem to start from 6pm to 9pm.
piva00
Similar experience for me but probably even more extreme.
I'm originally from São Paulo, Brazil, the Tropic of Capricorn almost cuts through the city itself. Sunrises and sunsets are very quick events, sitting somewhere to watch it would take some 30 minutes, and then darkness.
Even after 10+ years of living in Sweden I still get mesmerised by sunrises and sunsets here, they last for so long and I get to be awed by the changing of colours, shadows, shapes, for hours. It's one of my favourite things to do during summers, just to be out somewhere by a lake with some friends, having food and drinks, and watching the endless twilight.
madcaptenor
"One of the more interesting features I hadn’t appreciated before is that when you get close to the Arctic circle, the length of the days is essentially a zigzag, straight up from the winter solstice all the way to the summer solstice and back down again."
I had noticed this too and wondered if it was exactly true, with the "zigzag" being straight lines - I thought there might be a simple proof of this fact based on some trig identities. There's not, because it's not true - the lines aren't exactly straight, even if you ignore solar refraction - but it's a very good approximation.
jampekka
The calculated daylight even downplays the actual light at the high (or low) latitudes quite a bit. E.g. at latitude 60 there's a "nominal" midsummer night of about four hours, but it doesn't really get dark, as the light from the refraction is quite strong even with the disk not being visible.
madcaptenor
That's called "twilight". In the section "Atmospheric refraction and the solar limb" there's a modified sunrise equation with a variable "a" and text suggesting a correction of 50 minutes of arc there.
If you replace 50 minutes with: - 6 degrees, you get the times of "civil twilight" (roughly speaking, when you don't need light outside). At 60 degrees north at midsummer the minimum altitude of the sun will be about -6.5 degrees so almost all of the nominal night is civil twilight. - 12 degrees is "nautical twilight" (horizon clearly visible) - 18 degrees is "astronomical twilight" (sky is dark enough for all astronomical observations).
(It's possible that those are defined as 6 degrees + 50 minutes, etc.)
qwertox
And it's not just "sunset + X minutes" where X would be a constant. In the winter this X is much shorter than in the summer.
For me X is then a "travelling" value which in the winter is at 1/3 between sunset (0°) and civil dusk (-6°), and in the summer it goes up to 2/3. Calculated as the moment when the blinds go down.
I'm using https://astral.readthedocs.io for this.
madcaptenor
What's the reasoning behind using a different value in winter than summer? Your winter value roughly corresponds to -2°, your summer value to -4°.
qwertox
You made me check the code and actually I have it the other way around (and with different ratios, winter=-6°, summer=-2°), because else the blinds would go down too late in the summer (after 22:00).
jameshart
Even in the UK around 51-52°N you get a few nights around midsummer where it never truly gets dark - no darker than ‘nautical twilight’ at least.
sunshinesnacks
I think the section “Atmospheric refraction and the solar limb” near the end of the article addresses this.
madcaptenor
Not exactly; even after the sun is fully below the horizon there's some light. See the interactive graph - the times aren't long enough for twilight. But you can use a larger value of "a" in the equation above it to make that change.
sunshinesnacks
Yeah, you’re right. Something like civil twilight, as you mentioned above, should get it closer to what is being discussed here.
kaffekaka
Coming from middle of Sweden I remember the first time I spent a midsummers night in Lund in the south if Sweden and was astonished that the night was in fact dark! In my hometown, well below the arctic circle, the month of June is still constant daylight.
euroderf
The seasonal extremes of daylight are so extreme up here in Finland that the cycle of night & day seems a bit less like a 24-hour cycle and a bit more like a 365-day cycle.
An artifact of this is that my 5yo might not see a dark sky for the entire summer, unless we keep him up awake for the traditional Midsummer hangin'-out.
divbzero
A closely related follow-up blog post could be titled: “How Long Twilight Lasts”.
kccqzy
Very interesting discussion! I did a less theoretical approach a while ago to calculate the same thing: I just go to timeanddate.com, find the city I'm interested in, go to its sun page (example for New York https://www.timeanddate.com/sun/usa/new-york), and find the table that shows the difference in daylight minutes per day. No math or programming needed, just copy-paste and some buttons in Excel.
Not as satisfying as a derivation here, but a quicker way to get the answer.
EDIT: I did a spot check for Rovaniemi, Finland. This city is far north enough that the sun is up all day (66.5 degrees). But the graph on this page seems to be a little bit off: it requires an even higher latitude for that to show up.
mig39
Moving to Northern Canada has made me really really appreciate Spring. Going to work in the dark then going home in the dark is exhausting. I'm at 56ºN. I imagine it's worse for those who are even further North.
neilwilson
Scotland then :-)
July 5th through September in Seattle are a dream; incredibly long days, dry but not too hot. The sun never sets. I've been a lot of places on the planet and PNW summers are uniquely great.
However, during the winter it's dreary, it's dark by noon, and every year around October the raven comes tapping at my chamber door.
July of 2020 I left and went south to Central America. That first 'winter' I kept waiting for my annual S-A-D season to start. It didn't. The second 'winter' was worse because I reasoned the lst time could have been endorphins keeping me going. I was really expecting any day for the depression to start. And again, it didn't. December and January felt normal. That very consistent 7am it's bright sunny day and at 7pm it's dark night all year is helpful.
Quite literally, I never intended to return to Seattle, but with the recent economic turmoil it worked out that way. S-A-D season kicked off like usual, even with the 10,000 IUs of Vitamin D.
Without a job I moved to Eastern Washington, and within a month I was much better, life got easier and the future was far less inscrutable. I have the energy to do the work.
Many people love and appreciate the Seattle climate just as it is; I don't know really anyone that reacts quite as severely as I do to it. Not being in Seattle weather means I get 6 more months of life every year. It kills me how much time I wasted trying to 'fix myself' in a place I just wasn't meant to be.