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ERA5 climatology · 2015–2024
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The best month.

Pick a month and every watch point is ranked by its real monthly cloud cover — 2015–2024 reanalysis means, lower is better — with the spots that have no true darkness that month set apart. Or pick a spot for its twelve-month chart.

Clear sky by month · Oulu100 − mean cloud cover · higher is better

Clearest dark months here (outlined): Mar, Sep, Oct. Faint: no night with an hour of astronomical darkness — white nights, twilight only (May, Jun, Jul, Aug). Part-faint months are dark on some nights only: dark until 5 Apr; dark from 5 Sep. ERA5 reanalysis, 2015–2024 monthly mean. Climatology, not a forecast — a regional ~25 km grid; local microclimates are not captured. Darkness & moon calendar → Best month, all spots →

● Tonight at Oulu — live →

Clearest dark skies in December

The aurora belt · Kp 3 or lessAll 70 spots

Top three: South Africa (Cape Point / Hermanus), South Australia coast (Kangaroo Is.), Victoria coast (Phillip Island). 68 watch points with at least one night of an hour's astronomical darkness this month, ranked by clear sky (100 − mean cloud cover); dark hours are the mean over the month's dark nights, and a part-dark month says when its darkness starts or ends. Cloud is only one of the three conditions — a clear Kp 9 spot is almost never lit; the threshold shown is each spot's own.

  1. 01South Africa (Cape Point / Hermanus) Africa · S60%6.1hKp 9+
  2. 02South Australia coast (Kangaroo Is.) Oceania · S50%5.9hKp 7+
  3. 03Victoria coast (Phillip Island) Oceania · S44%5.3hKp 6+
  4. 04Launceston Oceania · S43%4.6hKp 5+
  5. 05North Dakota North America · N36%11.8hKp 5+
  6. 06Coldfoot / Bettles North America · N35%13.1hKp 0+
  7. 07Edmonton North America · N35%12.1hKp 4+
  8. 08Hobart Oceania · S35%4.2hKp 5+
  9. 09Northern Maine (Acadia) North America · N34%11.7hKp 5+
  10. 10Christchurch Oceania · S34%4hKp 6+
  11. 11Fairbanks North America · N33%12.9hKp 1+
  12. 12Lake Tekapo (Aoraki Mackenzie) Oceania · S33%3.8hKp 5+
  13. 13Fort McMurray North America · N32%12.3hKp 3+
  14. 14Bruny Island / Cockle Creek Oceania · S32%4hKp 4+
  15. 15Ilulissat Greenland · N29%13.3hKp 0+
  16. 16Queenstown / Southland Oceania · S29%3.4hKp 5+
  17. 17Nuuk Greenland · N27%12.8hKp 1+
  18. 18Yellowknife North America · N27%12.7hKp 1+
  19. 19Aberdeenshire Northern Europe · N27%12.3hKp 5+
  20. 20Jasper North America · N27%12hKp 4+
  21. 21Dunedin / Otago Peninsula Oceania · S27%3.1hKp 5+
  22. 22Denali North America · N26%12.7hKp 2+
  23. 23Invercargill Oceania · S26%2.8hKp 5+
  24. 24Kangerlussuaq Greenland · N25%13.1hKp 0+
  25. 25Reykjavík Northern Europe · N25%12.8hKp 2+
  26. 26Edinburgh Northern Europe · N23%12.2hKp 5+
  27. 27Whitehorse North America · N22%12.6hKp 3+
  28. 28Orkney Northern Europe · N22%12.4hKp 5+
  29. 29Lofoten Islands Northern Europe · N21%13.2hKp 1+
  30. 30Iqaluit North America · N21%12.8hKp 1+
  31. 31Faroe Islands (Tórshavn) Northern Europe · N21%12.7hKp 3+
  32. 32Shetland Northern Europe · N21%12.5hKp 4+
  33. 33Oslo Northern Europe · N21%12.5hKp 4+
  34. 34Caithness (north Highlands) Northern Europe · N21%12.4hKp 5+
  35. 35Svalbard (Longyearbyen) Northern Europe · N20%15.1hKp 0+
  36. 36Svolvær Northern Europe · N20%13.2hKp 2+
  37. 37Dawson City North America · N20%12.8hKp 1+
  38. 38Stockholm Northern Europe · N20%12.5hKp 4+
  39. 39Stewart Island / Rakiura Oceania · S20%2.5hKp 4+
  40. 40Copenhagen Northern Europe · N19%12.2hKp 5+
  41. 41Senja Northern Europe · N18%13.4hKp 1+
  42. 42Kirkenes Northern Europe · N18%13.4hKp 1+
  43. 43Kiruna Northern Europe · N18%13.2hKp 2+
  44. 44Washington (North Cascades) North America · N18%11.8hKp 6+
  45. 45Alta Northern Europe · N17%13.4hKp 1+
  46. 46Anchorage North America · N17%12.6hKp 3+
  47. 47Donegal Northern Europe · N17%12.2hKp 5+
  48. 48Northern Minnesota (Voyageurs) North America · N17%11.8hKp 5+
  49. 49Montana (Glacier NP) North America · N17%11.8hKp 5+
  50. 50Utqiaġvik (Barrow) North America · N16%13.6hKp 0+
  51. 51Inari Northern Europe · N16%13.3hKp 1+
  52. 52Helsinki Northern Europe · N16%12.5hKp 4+
  53. 53Churchill North America · N16%12.4hKp 1+
  54. 54Ivalo Northern Europe · N15%13.3hKp 2+
  55. 55Nellim Northern Europe · N15%13.3hKp 2+
  56. 56Iceland (countrywide) Northern Europe · N15%12.9hKp 2+
  57. 57Oulu Northern Europe · N15%12.9hKp 3+
  58. 58Lyngen Northern Europe · N14%13.4hKp 1+
  59. 59Murmansk / Kola Peninsula Northern Europe · N14%13.3hKp 2+
  60. 60Rovaniemi Northern Europe · N14%13hKp 2+
  61. 61Tromsø Northern Europe · N12%13.4hKp 1+
  62. 62Saariselkä Northern Europe · N12%13.3hKp 2+
  63. 63Akureyri Northern Europe · N12%13hKp 1+
  64. 64Estonia (Tartu / coast) Northern Europe · N12%12.4hKp 5+
  65. 65Michigan Upper Peninsula (Keweenaw) North America · N12%11.7hKp 5+
  66. 66Skibotn Northern Europe · N9%13.4hKp 1+
  67. 67Abisko Northern Europe · N9%13.2hKp 1+
  68. 68Kilpisjärvi Northern Europe · N8%13.3hKp 1+
clear = 100 − mean cloud cover · dark = mean hours of astronomical dark · glow = the spot's Kp for a glow

No true darkness in December

No night this month reaches an hour of astronomical darkness — clear or not, the aurora is not visible. Their cloud figures are shown for the record.

Cloud: Open-Meteo Historical Weather API (ERA5 reanalysis), cloud_cover_mean (daily), averaged by calendar month, 2015–2024. Climatology, not a forecast — a regional ~25 km grid; local microclimates (a valley's "blue hole") are not captured. Darkness: astronomical (sun below −18°) computed for the 15th of the month at each spot. Night-by-night darkness & moon → Season sheet (PDF) → Plan the trip →