Skip to content
ERA5 climatology · 2015–2024
When to go

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 · Hobart100 − mean cloud cover · higher is better

Clearest dark months here (outlined): Feb, Apr, May. 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 Hobart — live →

Clearest dark skies in April

The aurora belt · Kp 3 or lessAll 70 spots

Top three: Fairbanks, Yellowknife, Dawson City. 16 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. 01Fairbanks North America · N· dark until 6 Apr45%2.4hKp 1+
  2. 02Yellowknife North America · N· dark until 12 Apr43%3.2hKp 1+
  3. 03Dawson City North America · N· dark until 8 Apr43%2.7hKp 1+
  4. 04Whitehorse North America · N· dark until 17 Apr38%3.6hKp 3+
  5. 05Fort McMurray North America · N· dark until 29 Apr36%4.2hKp 3+
  6. 06Oulu Northern Europe · N· dark until 5 Apr36%2.5hKp 3+
  7. 07Denali North America · N· dark until 11 Apr35%2.9hKp 2+
  8. 08Anchorage North America · N· dark until 16 Apr34%3.4hKp 3+
  9. 09Rovaniemi Northern Europe · N· dark until 2 Apr33%1.4hKp 2+
  10. 10Churchill North America · N· dark until 23 Apr27%3.9hKp 1+
  11. 11Iqaluit North America · N· dark until 9 Apr27%2.8hKp 1+
  12. 12Faroe Islands (Tórshavn) Northern Europe · N· dark until 14 Apr25%3.2hKp 3+
  13. 13Nuuk Greenland · N· dark until 8 Apr25%2.6hKp 1+
  14. 14Reykjavík Northern Europe · N· dark until 8 Apr23%2.6hKp 2+
  15. 15Akureyri Northern Europe · N· dark until 4 Apr23%2hKp 1+
  16. 16Iceland (countrywide) Northern Europe · N· dark until 7 Apr21%2.5hKp 2+
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 →