Ashburton · September 2027
Southern lights in Ashburton in September 2027
Answer
September against the rest of the year
September cloud at Ashburton averages 66% in NASA POWER's 2001 to 2020 record, close to its yearly mean of 65%. June is Ashburton's clearest month at 60%. By civil night times clear sky, September scores 3.8 hours at Ashburton, 6th of 12. Seattle, 12,042 km away, averages 53%, clearer by 13 points.
Civil night at Ashburton starts September at 11 h 51 min and reaches 10 h 25 min by September 30, 1.4 hours shorter. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 8.9 hours on the 15th.
September night by night
September opens toward a new moon on Sep 1 and Sep 30, with full moon on Sep 16, in Pacific/Auckland dates. Ashburton gets 164 hours of civil night with the moon below the horizon across the month. The best of them for moon-free darkness inside 10 PM to 2 AM: Sep 1 (4 h), Sep 2 (4 h), Sep 3 (4 h).
- 1
1% lit
11.8 h
- 2
5% lit
10.4 h
- 3
11% lit
9.1 h
- 4
19% lit
7.8 h
- 5
28% lit
6.5 h
- 6
37% lit
5.3 h
- 7
47% lit
4.3 h
- 8
57% lit
3.3 h
- 9
67% lit
2.5 h
- 10
75% lit
1.9 h
- 11
83% lit
1.3 h
- 12
89% lit
0.9 h
- 13
94% lit
0.5 h
- 14
98% lit
0.1 h
- 15
100% lit
0.0 h
- 16
100% lit
0.0 h
- 17
98% lit
0.9 h
- 18
93% lit
2.0 h
- 19
88% lit
3.2 h
- 20
80% lit
4.3 h
- 21
71% lit
5.5 h
- 22
60% lit
6.6 h
- 23
49% lit
7.5 h
- 24
38% lit
8.3 h
- 25
27% lit
8.9 h
- 26
18% lit
9.4 h
- 27
10% lit
9.9 h
- 28
4% lit
10.3 h
- 29
1% lit
10.5 h
- 30
0% lit
10.4 h
Each cell is the night that starts on that date. Hours are civil-dark time with the moon below the horizon; the green rule scales with them. Green outline: new moon. Bone outline: full moon.
Activity in past Septembers
No whole Kp puts the average oval edge over Ashburton by SWPC's rule, so the GFZ record has no threshold to count for September. Ashburton sits at 47.2 degrees geomagnetic. The lowest NOAA storm level whose typical viewing latitude reaches it is G4 (Kp = 8, including a 9-). Even Kp 9 does not put the average oval edge overhead by SWPC's rule.
September across New Zealand
Coming from August (12.6 hours at Ashburton), September loses darkness, and October brings shorter nights (9.6 hours on the 15th). The September equinox falls on September 23, 17:56 Ashburton time, inside the weeks SWPC links with larger storms.
Darkness and moon, every night
| Night | Civil | Astronomical | Moon-free dark | Moon-free, 10 PM to 2 AM | Moon lit |
|---|---|---|---|---|---|
| Wed Sep 1 | 11 h 51 min | 9 h 38 min | 11 h 45 min | 4 h | 1% |
| Thu Sep 2 | 11 h 48 min | 9 h 35 min | 10 h 24 min | 4 h | 5% |
| Fri Sep 3 | 11 h 46 min | 9 h 32 min | 9 h 6 min | 4 h | 11% |
| Sat Sep 4 | 11 h 43 min | 9 h 29 min | 7 h 48 min | 3 h 25 min | 19% |
| Sun Sep 5 | 11 h 40 min | 9 h 26 min | 6 h 33 min | 2 h 11 min | 28% |
| Mon Sep 6 | 11 h 37 min | 9 h 23 min | 5 h 21 min | 1 h 1 min | 37% |
| Tue Sep 7 | 11 h 34 min | 9 h 20 min | 4 h 16 min | 0 min | 47% |
| Wed Sep 8 | 11 h 31 min | 9 h 18 min | 3 h 19 min | 0 min | 57% |
| Thu Sep 9 | 11 h 28 min | 9 h 15 min | 2 h 31 min | 0 min | 67% |
| Fri Sep 10 | 11 h 26 min | 9 h 12 min | 1 h 52 min | 0 min | 75% |
| Sat Sep 11 | 11 h 23 min | 9 h 8 min | 1 h 20 min | 0 min | 83% |
| Sun Sep 12 | 11 h 20 min | 9 h 5 min | 53 min | 0 min | 89% |
| Mon Sep 13 | 11 h 17 min | 9 h 2 min | 30 min | 0 min | 94% |
| Tue Sep 14 | 11 h 14 min | 8 h 59 min | 8 min | 0 min | 98% |
| Wed Sep 15 | 11 h 11 min | 8 h 56 min | 0 min | 0 min | 100% |
| Thu Sep 16 | 11 h 8 min | 8 h 53 min | 0 min | 0 min | 100% |
| Fri Sep 17 | 11 h 5 min | 8 h 50 min | 57 min | 0 min | 98% |
| Sat Sep 18 | 11 h 2 min | 8 h 47 min | 2 h 3 min | 0 min | 93% |
| Sun Sep 19 | 10 h 59 min | 8 h 43 min | 3 h 11 min | 8 min | 88% |
| Mon Sep 20 | 10 h 56 min | 8 h 40 min | 4 h 21 min | 1 h 19 min | 80% |
| Tue Sep 21 | 10 h 53 min | 8 h 37 min | 5 h 31 min | 2 h 30 min | 71% |
| Wed Sep 22 | 10 h 50 min | 8 h 33 min | 6 h 36 min | 3 h 36 min | 60% |
| Thu Sep 23 | 10 h 47 min | 8 h 30 min | 7 h 33 min | 4 h | 49% |
| Fri Sep 24 | 10 h 44 min | 8 h 27 min | 8 h 19 min | 4 h | 38% |
| Sat Sep 25 | 10 h 41 min | 8 h 23 min | 8 h 57 min | 3 h | 27% |
| Sun Sep 26 | 10 h 38 min | 8 h 20 min | 9 h 27 min | 4 h | 18% |
| Mon Sep 27 | 10 h 35 min | 8 h 17 min | 9 h 52 min | 4 h | 10% |
| Tue Sep 28 | 10 h 32 min | 8 h 13 min | 10 h 15 min | 4 h | 4% |
| Wed Sep 29 | 10 h 29 min | 8 h 10 min | 10 h 29 min | 4 h | 1% |
| Thu Sep 30 | 10 h 25 min | 8 h 6 min | 10 h 25 min | 4 h | 0% |
Questions
- Can you see the southern lights in Ashburton in September?
- On dark, clear nights with enough activity. 30 of 30 nights at Ashburton have civil darkness.
- How dark is Ashburton in September?
- Ashburton averages 11.2 hours of civil night a night in September 2027, from 11 h 51 min on the 1st to 10 h 25 min on the last night.
- How cloudy is Ashburton in September?
- NASA POWER's 2001 to 2020 climatology gives Ashburton's 1 degree cell 66% mean cloud in September, against 65% for the whole year. It is an all-hours average, not a forecast.
- What is the best night in September 2027 for aurora in Ashburton?
- By darkness and moon alone, Sep 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Ashburton. Activity on that date will only be known hours ahead.
- Is September or October better in Ashburton?
- By civil night times the clear share, September scores 3.8 hours at Ashburton and October 3.1. September comes out ahead.
Sources and verification
- SunCalchttps://github.com/mourner/suncalc
- NASA POWER climatologyhttps://power.larc.nasa.gov/docs/services/api/temporal/climatology/
- GFZ Potsdam Kp indexhttps://kp.gfz.de/en/data
- NOAA SWPC, Tips on viewing the aurorahttps://www.spaceweather.gov/content/tips-viewing-aurora
Quoted figures last checked against their sources on 2026-09-30; next review 2026-12-31. Computed figures come from SunCalc and the IGRF-14 dipole as described in the methodology. Every quote is listed in the sources ledger.