Starry Memory

Night length and darkness calendar for Sollentuna

Use the free local tool

This page provides a result prefilled with the place and coordinates. The calculations and phone gyroscope work without an order; the HD poster remains optional. Open the twelve-month Sollentuna calendar

Compare all twelve months and find the longest local observing windows

A good month for stargazing is not the same everywhere. Latitude changes the seasonal balance between daylight and night. The table below estimates day and night length around the middle of every month for Sollentuna, using a flat astronomical horizon and explaining the limits of twilight, weather and terrain.

Why choose Starry Memory

Twelve local estimates — Monthly night duration ranges from 5 h 46 to 18 h 15 in the flat-horizon model.
GPS · IANA reference — Exact reference: Stockholm, 59.4280° N, 17.9509° E, Europe/Stockholm.
Free tool — The city-specific tool works free in the browser and does not create an order.
Transparent limits — Weather, light pollution and local obstructions are stated as limits instead of being hidden.

Sollentuna's changing light is read month by month, using its actual seasonal range rather than generic observing advice. Its verifiable starting point is GeoNames 2675408, 59.4280° N, 17.9509° E, in timezone Europe/Stockholm.

Twelve monthly light estimates for Sollentuna

The following pairs are approximate daylight / night duration around the 15th of each month: January: 6 h 31 / 17 h 29; February: 8 h 52 / 15 h 08; March: 11 h 22 / 12 h 38; April: 14 h 10 / 9 h 50; May: 16 h 41 / 7 h 19; June: 18 h 14 / 5 h 46; July: 17 h 35 / 6 h 25; August: 15 h 16 / 8 h 44; September: 12 h 30 / 11 h 30; October: 9 h 47 / 14 h 13; November: 7 h 12 / 16 h 48; December: 5 h 45 / 18 h 15. The longest estimated night in this model is December at 18 h 15; the shortest is June at 5 h 46. “Night” here is the complement of daylight on a flat horizon. Civil, nautical and astronomical twilight are not interchangeable, and weather is not predicted by this table.

Sollentuna's verifiable local record

Calculation identity: GeoNames 2675408 · city Sollentuna · region Stockholm · country Sweden · national selection rank 7 · reference population 139,606 · source elevation —. Spatial fingerprint: latitude 59.42804 · longitude 17.95093 · north hemisphere · timezone Europe/Stockholm · celestial-pole altitude 59.4°. Seasonal signature: longest night in December, 18 h 15 · shortest night in June, 5 h 46 · range 12.49 hours. Meridian star markers: Cassiopeia 89.4° * · Ursa Major 86.6° * · Draco 84.4° * · Cepheus 79.4° * · Perseus 75.6° * · Auriga 72.6° *. Nearby catalogue cities: Stockholm 13 km · Uppsala 51 km · Västerås 82 km. First regional eclipse shortlist: 2027-02-20 Penumbral lunar eclipse 23:14 UTC · 2027-08-02 Total solar eclipse 10:07 UTC · 2028-01-12 Partial lunar eclipse 04:14 UTC. Together these values form the local evidence record for the “night calendar” page; they change with place and remain separate from real weather.

Sollentuna compared with nearby catalogue cities

1. Sollentuna → Stockholm: 12.8 km · Δlat -0.099° · Δlon +0.118° · Δpole -0.1° · timezone Europe/Stockholm = Europe/Stockholm · longest night December 18 h 13 | 2. Sollentuna → Uppsala: 51.0 km · Δlat +0.431° · Δlon -0.312° · Δpole +0.5° · timezone Europe/Stockholm = Europe/Stockholm · longest night December 18 h 23 | 3. Sollentuna → Västerås: 81.6 km · Δlat +0.188° · Δlon -1.398° · Δpole +0.2° · timezone Europe/Stockholm = Europe/Stockholm · longest night December 18 h 19. Monthly night comparison with the nearest catalogue reference — January: Sollentuna 17 h 29 / Stockholm 17 h 28 / Δ +0.02 h · February: Sollentuna 15 h 08 / Stockholm 15 h 08 / Δ +0.01 h · March: Sollentuna 12 h 38 / Stockholm 12 h 38 / Δ +0.01 h · April: Sollentuna 9 h 50 / Stockholm 9 h 50 / Δ -0.01 h · May: Sollentuna 7 h 19 / Stockholm 7 h 20 / Δ -0.02 h · June: Sollentuna 5 h 46 / Stockholm 5 h 47 / Δ -0.03 h · July: Sollentuna 6 h 25 / Stockholm 6 h 27 / Δ -0.03 h · August: Sollentuna 8 h 44 / Stockholm 8 h 44 / Δ -0.01 h · September: Sollentuna 11 h 30 / Stockholm 11 h 30 / Δ +0.00 h · October: Sollentuna 14 h 13 / Stockholm 14 h 13 / Δ +0.01 h · November: Sollentuna 16 h 48 / Stockholm 16 h 47 / Δ +0.02 h · December: Sollentuna 18 h 15 / Stockholm 18 h 13 / Δ +0.03 h. For the night calendar, north-south movement is the primary signal: compare Sollentuna's seasonal range with the numbered maximum nights of its neighbours.

The astronomical fingerprint of Sollentuna

Sollentuna is represented by 59.4280° N, 17.9509° E, in Stockholm, using the IANA zone Europe/Stockholm. This is a high-latitude viewpoint: the relevant celestial pole stands about 59.4° above its horizon. GeoNames record 2675408 supplies the geographic reference; its population field is 139,606 and is used for catalogue selection, not presented as a live census. No source elevation is used, so a flat horizon remains the transparent default.

Latitude-screened constellations for Sollentuna

Each entry below gives an approximate maximum altitude at meridian transit and a practical season; an asterisk means circumpolar in this simplified centroid model: Cassiopeia: 89.4°, all year *; Ursa Major: 86.6°, all year *; Draco: 84.4°, all year *; Cepheus: 79.4°, all year *; Perseus: 75.6°, all year *; Auriga: 72.6°, all year *; Ursa Minor: 72.4°, all year *; Cygnus: 70.6°, all year *; Andromeda: 68.6°, all year *; Lyra: 66.6°, all year *; Boötes: 60.6°, spring; Gemini: 52.6°, winter; Taurus: 48.6°, winter; Leo: 45.6°, spring. This is a planning guide, not a promise that every star will be visible from a bright street. Date, hour, local obstructions and light pollution still matter. The live sky tool performs the date-specific projection that a static latitude table cannot.

What the calculation does — and does not claim

Coordinates, date and local time feed the same astronomical workflow used by the poster. The HYG catalogue provides star entries, while Astronomy Engine calculates moving bodies. The page does not claim that city-centre coordinates equal a hospital, venue or home: selecting an autocomplete suggestion replaces the shortcut with that location. It also separates astronomical geometry from weather and light pollution, so a correct map never becomes a claim that the ground-level sky was cloudless.

Free gyroscope first, optional poster second

On a compatible phone, the gyroscope turns the calculated sky into a movable window: tilt and rotate to explore, with star names shown beside key points. That experience is free. If a date deserves a keepsake, the same place can continue into the editor. The protected preview remains watermarked before payment; the €3.99 purchase unlocks the 4960 × 7016 px, 300 DPI file. Physical formats appear only when availability, delivery supplement and timing can be checked for the destination. Checkout is in euros; the card issuer shows the current conversion to Swedish kronor (SEK).

Frequently asked questions

Is night length the same as astronomical darkness?

No. The table shows 24 hours minus estimated daylight. In Sollentuna, twilight shortens fully dark conditions, especially near the longest days.

Can I replace the centre of Sollentuna with an exact address?

Yes. Choose the intended autocomplete suggestion; its coordinates replace the city shortcut. Unselected free text is never silently sent to a default city.

Is the Sollentuna tool free?

Yes. The local calculation, tables and gyroscope exploration can be used without payment. Only the unlocked HD poster is paid.

Does this guarantee clear-sky visibility?

No. The calculations describe geometry. Cloud, terrain, buildings and light pollution can change what a person sees from the ground.

Do I have to buy a poster?

No. The tool stands on its own. If wanted, the watermark-free 4960 × 7016 px, 300 DPI file costs €3.99. Checkout is in euros; the card issuer shows the current conversion to Swedish kronor (SEK).

Open the twelve-month Sollentuna calendar