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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 · Whitehorse100 − mean cloud cover · higher is better

Clearest dark months here (outlined): Feb, Mar, Apr. Faint: no night with an hour of astronomical darkness — white nights, twilight only (May, Jun, Jul). Part-faint months are dark on some nights only: dark until 17 Apr; dark from 24 Aug. 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 Whitehorse — live →

Clearest dark skies in April

The aurora belt · Kp 3 or lessAll 70 spots

Top three: South Africa (Cape Point / Hermanus), Christchurch, Copenhagen. 52 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 · S58%10hKp 9+
  2. 02Christchurch Oceania · S45%10hKp 6+
  3. 03Copenhagen Northern Europe · N45%4.5hKp 5+
  4. 04Fairbanks North America · N· dark until 6 Apr45%2.4hKp 1+
  5. 05South Australia coast (Kangaroo Is.) Oceania · S44%10hKp 7+
  6. 06Lake Tekapo (Aoraki Mackenzie) Oceania · S43%10hKp 5+
  7. 07Yellowknife North America · N· dark until 12 Apr43%3.2hKp 1+
  8. 08Dawson City North America · N· dark until 8 Apr43%2.7hKp 1+
  9. 09Launceston Oceania · S42%10hKp 5+
  10. 10Oslo Northern Europe · N· dark until 20 Apr42%3.6hKp 4+
  11. 11Stockholm Northern Europe · N· dark until 21 Apr40%3.8hKp 4+
  12. 12Hobart Oceania · S39%10hKp 5+
  13. 13Victoria coast (Phillip Island) Oceania · S38%10hKp 6+
  14. 14North Dakota North America · N38%6.4hKp 5+
  15. 15Edmonton North America · N38%5.2hKp 4+
  16. 16Whitehorse North America · N· dark until 17 Apr38%3.6hKp 3+
  17. 17Helsinki Northern Europe · N· dark until 19 Apr38%3.6hKp 4+
  18. 18Dunedin / Otago Peninsula Oceania · S37%9.9hKp 5+
  19. 19Patagonia (El Calafate) South America · S37%9.9hKp 9+
  20. 20Fort McMurray North America · N· dark until 29 Apr36%4.2hKp 3+
  21. 21Estonia (Tartu / coast) Northern Europe · N· dark until 24 Apr36%3.9hKp 5+
  22. 22Oulu Northern Europe · N· dark until 5 Apr36%2.5hKp 3+
  23. 23Denali North America · N· dark until 11 Apr35%2.9hKp 2+
  24. 24Michigan Upper Peninsula (Keweenaw) North America · N34%6.5hKp 5+
  25. 25Edinburgh Northern Europe · N34%4.4hKp 5+
  26. 26Anchorage North America · N· dark until 16 Apr34%3.4hKp 3+
  27. 27Northern Maine (Acadia) North America · N33%6.7hKp 5+
  28. 28Montana (Glacier NP) North America · N33%6.3hKp 5+
  29. 29Rovaniemi Northern Europe · N· dark until 2 Apr33%1.4hKp 2+
  30. 30Northern Minnesota (Voyageurs) North America · N32%6.4hKp 5+
  31. 31Jasper North America · N32%5.4hKp 4+
  32. 32Aberdeenshire Northern Europe · N· dark until 28 Apr32%4.1hKp 5+
  33. 33Bruny Island / Cockle Creek Oceania · S31%10hKp 4+
  34. 34Orkney Northern Europe · N· dark until 22 Apr31%3.9hKp 5+
  35. 35Shetland Northern Europe · N· dark until 18 Apr31%3.6hKp 4+
  36. 36Queenstown / Southland Oceania · S29%9.9hKp 5+
  37. 37Washington (North Cascades) North America · N29%6.3hKp 6+
  38. 38Punta Arenas South America · S28%9.8hKp 9+
  39. 39Donegal Northern Europe · N28%4.9hKp 5+
  40. 40Caithness (north Highlands) Northern Europe · N· dark until 24 Apr28%3.9hKp 5+
  41. 41Invercargill Oceania · S27%9.9hKp 5+
  42. 42Falkland Islands South Atlantic · S27%9.8hKp 9+
  43. 43Churchill North America · N· dark until 23 Apr27%3.9hKp 1+
  44. 44Iqaluit North America · N· dark until 9 Apr27%2.8hKp 1+
  45. 45Faroe Islands (Tórshavn) Northern Europe · N· dark until 14 Apr25%3.2hKp 3+
  46. 46Nuuk Greenland · N· dark until 8 Apr25%2.6hKp 1+
  47. 47Ushuaia / Tierra del Fuego South America · S23%9.7hKp 8+
  48. 48Reykjavík Northern Europe · N· dark until 8 Apr23%2.6hKp 2+
  49. 49Akureyri Northern Europe · N· dark until 4 Apr23%2hKp 1+
  50. 50Iceland (countrywide) Northern Europe · N· dark until 7 Apr21%2.5hKp 2+
  51. 51Stewart Island / Rakiura Oceania · S20%9.9hKp 4+
  52. 52South Georgia South Atlantic · S8%9.7hKp 8+
clear = 100 − mean cloud cover · dark = mean hours of astronomical dark · glow = the spot's Kp for a glow

No true darkness in April

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 →