4.8 usable nights
3–7 in the middle half of years · 1.6 typically near a dark moon.
137 astronomical-dark hours in an average month
20-year trip-planning baseline
When to plan an observing trip to Aoraki Mackenzie (Lake Tekapo)
June: 7.8 usable nights on average. A regional planning baseline, not a forecast for your trip.
Site darkness · modelled, not measured
Natural-dark skyBortle classes describe observed sky conditions; this brightness model does not establish a measured Bortle class.21.8–21.9 mag/arcsec²
The short answer
June has been strongest.
It averages 7.8 usable nights, versus 2.8 in December. A typical June lands between 7 and 9 usable nights.
Record2005–2024 · 20 complete years
Usable nightAt least 3 astronomical-dark hours and NASA POWER nighttime cloud ≤30%
Dark-moon nightUsable night with ≤25% illumination at local solar midnight
ResolutionCERES SYN1deg 1° cloud grid; regional climate, not a campsite guarantee
Seasonal fingerprint
Usable nights by month
Month by month
5.2 usable nights
4–6 in the middle half of years · 1.5 typically near a dark moon.
182 astronomical-dark hours in an average month
5.6 usable nights
5–7 in the middle half of years · 1.6 typically near a dark moon.
256 astronomical-dark hours in an average month
6.7 usable nights
4–10 in the middle half of years · 2.5 typically near a dark moon.
300 astronomical-dark hours in an average month
7.3 usable nights
4–10 in the middle half of years · 2.9 typically near a dark moon.
345 astronomical-dark hours in an average month
7.8 usable nights
7–9 in the middle half of years · 2.5 typically near a dark moon.
360 astronomical-dark hours in an average month
6.6 usable nights
5–8 in the middle half of years · 2.8 typically near a dark moon.
362 astronomical-dark hours in an average month
6.2 usable nights
4–8 in the middle half of years · 2.7 typically near a dark moon.
316 astronomical-dark hours in an average month
3.8 usable nights
2–5 in the middle half of years · 1.1 typically near a dark moon.
272 astronomical-dark hours in an average month
3.2 usable nights
1–5 in the middle half of years · 1.0 typically near a dark moon.
226 astronomical-dark hours in an average month
2.9 usable nights
2–4 in the middle half of years · 1.1 typically near a dark moon.
155 astronomical-dark hours in an average month
2.8 usable nights
2–4 in the middle half of years · 0.9 typically near a dark moon.
124 astronomical-dark hours in an average month
Use the baseline honestly
Climate chooses the month. Forecasts choose the night.
The cloud product is a roughly 1° regional grid. It can reveal seasonality, but it cannot know a mountain ridge, valley fog pocket, locked gate, smoke event or the exact sky you will get.
Source: NASA POWER daily data, parameter CLOUD_AMT_NIGHT from the CERES SYN1deg cloud product. GoodSeeing calculates astronomical darkness and lunar illumination independently for each place.