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. Calculate the sky over Boston now
A free local guide to the Moon, planets and constellations visible tonight
The night sky changes with both time and place. This page calculates tonight above Boston from its coordinates and local timezone, then lets you refine the location. The live tool identifies the Moon, bright planets and recognisable constellations around 22:00 local time without requiring a purchase.
Tonight in Boston is neither yesterday's sky nor another latitude's view: the calculation restarts from local place and time. Its verifiable starting point is GeoNames 4930956, 42.3584° N, 71.0598° W, in timezone America/New_York.
Boston is represented by 42.3584° N, 71.0598° W, in Massachusetts, using the IANA zone America/New_York. This is a mid-latitude viewpoint: the relevant celestial pole stands about 42.4° above its horizon. GeoNames record 4930956 supplies the geographic reference; its population field is 653,833 and is used for catalogue selection, not presented as a live census. The source elevation is 14 metres; terrain can hide a low object even when the geometric calculation says it rises. Each entry below gives an approximate maximum altitude at meridian transit and a practical season; an asterisk means circumpolar in this simplified centroid model: Ursa Major: 76.4°, all year *; Cassiopeia: 72.4°, all year *; Draco: 67.4°, all year *; Cepheus: 62.4°, all year *; Ursa Minor: 55.4°, all year *; Auriga: 89.6°, winter; Cygnus: 87.6°, summer; Perseus: 87.4°, winter; Andromeda: 85.6°, autumn; Lyra: 83.6°, summer; Boötes: 77.6°, spring; Gemini: 69.6°, winter; Taurus: 65.6°, winter; Leo: 62.6°, 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.
Calculation identity: GeoNames 4930956 · city Boston · region Massachusetts · country United States · national selection rank 24 · reference population 653,833 · source elevation 14 m. Spatial fingerprint: latitude 42.35843 · longitude -71.05977 · north hemisphere · timezone America/New_York · celestial-pole altitude 42.4°. Seasonal signature: longest night in December, 15 h 05 · shortest night in June, 8 h 55 · range 6.17 hours. Meridian star markers: Ursa Major 76.4° * · Cassiopeia 72.4° * · Draco 67.4° * · Cepheus 62.4° * · Ursa Minor 55.4° * · Auriga 89.6°. Nearby catalogue cities: Cambridge 4 km · New Haven 194 km · New York 306 km. First regional eclipse shortlist: 2027-02-20 Penumbral lunar eclipse 23:14 UTC · 2027-08-17 Penumbral lunar eclipse 07:14 UTC · 2028-01-12 Partial lunar eclipse 04:14 UTC. Together these values form the local evidence record for the “tonight” page; they change with place and remain separate from real weather.
1. Boston → Cambridge: 4.2 km · Δlat +0.017° · Δlon -0.046° · Δpole +0.0° · timezone America/New_York = America/New_York · longest night December 15 h 05 | 2. Boston → New Haven: 193.9 km · Δlat -1.050° · Δlon -1.868° · Δpole -1.1° · timezone America/New_York = America/New_York · longest night December 14 h 58 | 3. Boston → New York: 305.8 km · Δlat -1.644° · Δlon -2.946° · Δpole -1.7° · timezone America/New_York = America/New_York · longest night December 14 h 54. Monthly night comparison with the nearest catalogue reference — January: Boston 14 h 46 / Cambridge 14 h 46 / Δ +0.00 h · February: Boston 13 h 40 / Cambridge 13 h 40 / Δ +0.00 h · March: Boston 12 h 20 / Cambridge 12 h 20 / Δ +0.00 h · April: Boston 10 h 50 / Cambridge 10 h 50 / Δ +0.00 h · May: Boston 9 h 35 / Cambridge 9 h 35 / Δ +0.00 h · June: Boston 8 h 55 / Cambridge 8 h 55 / Δ +0.01 h · July: Boston 9 h 11 / Cambridge 9 h 11 / Δ +0.00 h · August: Boston 10 h 17 / Cambridge 10 h 17 / Δ +0.00 h · September: Boston 11 h 44 / Cambridge 11 h 44 / Δ +0.00 h · October: Boston 13 h 11 / Cambridge 13 h 11 / Δ +0.00 h · November: Boston 14 h 28 / Cambridge 14 h 28 / Δ +0.00 h · December: Boston 15 h 05 / Cambridge 15 h 05 / Δ +0.00 h. For tonight's sky, longitude changes local rotation while latitude changes altitude; the tool therefore starts from Boston and then accepts a more exact address.
The following pairs are approximate daylight / night duration around the 15th of each month: January: 9 h 14 / 14 h 46; February: 10 h 20 / 13 h 40; March: 11 h 40 / 12 h 20; April: 13 h 10 / 10 h 50; May: 14 h 25 / 9 h 35; June: 15 h 05 / 8 h 55; July: 14 h 49 / 9 h 11; August: 13 h 43 / 10 h 17; September: 12 h 16 / 11 h 44; October: 10 h 49 / 13 h 11; November: 9 h 32 / 14 h 28; December: 8 h 55 / 15 h 05. The longest estimated night in this model is December at 15 h 05; the shortest is June at 8 h 55. “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.
20 February 2027: Penumbral lunar eclipse, 23:14 UTC; 17 August 2027: Penumbral lunar eclipse, 07:14 UTC; 12 January 2028: Partial lunar eclipse, 04:14 UTC; 26 January 2028: Annular solar eclipse, 15:08 UTC; 14 January 2029: Partial solar eclipse, 17:13 UTC; 12 June 2029: Partial solar eclipse, 04:06 UTC. This is deliberately a regional shortlist. Solar-eclipse paths are narrow, lunar eclipses require the Moon to be above the local horizon, and both can be lost to cloud. Open the NASA source attached to each event before planning travel or observation; never look at the Sun without certified eclipse viewers.
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.
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 US dollars (USD).
The current summary targets about 22:00 local time in America/New_York. Recalculate after changing place; planetary altitude and constellation visibility move through the night.
Yes. Choose the intended autocomplete suggestion; its coordinates replace the city shortcut. Unselected free text is never silently sent to a default city.
Yes. The local calculation, tables and gyroscope exploration can be used without payment. Only the unlocked HD poster is paid.
No. The calculations describe geometry. Cloud, terrain, buildings and light pollution can change what a person sees from the ground.
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 US dollars (USD).
Calculate the sky over Boston now
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