Darker Nights

Midnight over Stockholm has gotten visibly darker, as the sun is starting to move into lower declinations. Gone is the very bright, at time glowing northern horizon (after midnight, 00.50 summer time). Yet, you can still experience a sense of bright summer night, only a bit later - at around 02.15 for example.

As the sun gets lower, Noctilucent Clouds at 80 km emerge in a brighter fashion, like it has been the case lately (past couple of weeks). Sometimes, when you have them already appearing around midsummer (late June), it doesn't get dark enough for them to really shine. But as the sun stands a bit lower - their electric blue appearance starts to get stronger.

Naturally, you can't see them all the time, simply because sometimes there are none. Other times, the sun is either too low or to high below the horizon. Since those clouds are basically only visible (during summer), when the sun is between -6° and -16° degrees below the horizon.

Albeit i find -16 degrees to be a bit too much. If the sun is 16 degrees below horizon, Noctilucent clouds would only be visible in a very narrow corridor, very low above the horizon.

June to August

I would generally say the sun should be around -6 and -13 degrees below the horizon, in order to make Noctilucent clouds become visible during summer. The peak is usually around mid July / Third week of July - but appear in the range between June until the first week of August. It is rare that I ever seen any after 5 Aug.

For 12th August, the sun dips down to a max of -15.5° degrees below the horizon around midnight (00.50). So, that is about the threshold of Noctilucent Clouds.

An Early Arrival 2024

In 2024, i took my first Noctilucent images already on 4 June - which i think was rather early.

Late date; 12 August 2022

One time, at my balcony i could spot, very low and rather weak - some Noctilucent clouds on 12 August 2022, around 01.49 summer time.

The curious thing about this event was, that we first had weak Auroras appearing around midnight 00.10. When those disappeared, Noctilucent clouds appeared instead around 01.35 and onwards. Those where however not visible (or present) 1 hour before...

Latest ever; 20 August 1993

I have a color negative from 20 Aug 1993, claiming to have seen Noctilucent Clouds. I say "claiming", because i have a tendency to give films and negatives a date, even when I can't remember or never took notes - then i make a date up. (Because I give them identification numbers, so i can sort and separate my filmrolls and negatives over the decades).

Therefore I can't swear on that the latest date ever to have seen Noctilucent Clouds, was on a 20 Aug 1993. I would have to see the whole film roll and see if it had a real or guessed date.

Making a long story short

The current ongoing Noctilucent Cloud Season is about to end.

We may have a week left or so...

4 August 1996 outbreak

That one surprised me, because it was so widespread (broad), very strong (bright) - and very late for being already into the month of August. So, I went out into the city with my twin-eyed Mamiya C330s camera (6x6 negatives) + Sekor 80mm ƒ 2.8 lens, with filmrolls of Fujifilm G400 super film.

Developed the film in the morning hours manually at my kitchen sink in the common C-41 film process... and made some color contacts prints of each film roll, like I always did back then.

Decades later, i scanned the negatives and stitched (3) negatives into a panorama you see below. Planet Venus was shining brightly as a morning star (to the right near a church tower and the boat).