Ushuaia · July 2027
Southern lights in Ushuaia in July 2027
Answer
July against the rest of the year
July cloud at Ushuaia averages 72% in NASA POWER's 2001 to 2020 record, 6 points clearer than its yearly mean. No month at Ushuaia is clearer. That makes July the best month of Ushuaia's year by civil night times clear sky, 4.1 hours. Buffalo, 10,909 km away, averages 56%, clearer by 16 points.
Civil night at Ushuaia starts July at 15 h 4 min and reaches 13 h 59 min by July 31, 1.1 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 11.7 hours on the 15th.
July night by night
July opens toward a new moon on Jul 4, with full moon on Jul 18, in America/Argentina/Ushuaia dates. Ushuaia gets 232 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: Jul 1 (4 h), Jul 2 (4 h), Jul 3 (4 h).
- 1
6% lit
15.1 h
- 2
2% lit
15.1 h
- 3
0% lit
15.0 h
- 4
2% lit
15.0 h
- 5
6% lit
13.6 h
- 6
13% lit
12.0 h
- 7
22% lit
10.4 h
- 8
32% lit
8.9 h
- 9
43% lit
7.5 h
- 10
54% lit
6.0 h
- 11
64% lit
4.6 h
- 12
74% lit
3.3 h
- 13
82% lit
2.0 h
- 14
89% lit
0.9 h
- 15
94% lit
0.1 h
- 16
98% lit
0.0 h
- 17
100% lit
0.0 h
- 18
100% lit
0.0 h
- 19
98% lit
0.5 h
- 20
95% lit
1.7 h
- 21
90% lit
2.9 h
- 22
83% lit
4.1 h
- 23
75% lit
5.3 h
- 24
66% lit
6.6 h
- 25
56% lit
7.9 h
- 26
46% lit
9.3 h
- 27
35% lit
10.8 h
- 28
25% lit
12.2 h
- 29
16% lit
13.3 h
- 30
8% lit
14.0 h
- 31
3% lit
14.0 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 Julys
No whole Kp puts the average oval edge over Ushuaia by SWPC's rule, so the GFZ record has no threshold to count for July. Ushuaia sits at 45.6 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.
July across Argentina
Coming from June (15.1 hours at Ushuaia), July loses darkness, and August brings shorter nights (13.1 hours on the 15th).
Darkness and moon, every night
| Night | Civil | Astronomical | Moon-free dark | Moon-free, 10 PM to 2 AM | Moon lit |
|---|---|---|---|---|---|
| Thu Jul 1 | 15 h 4 min | 12 h 3 min | 15 h 4 min | 4 h | 6% |
| Fri Jul 2 | 15 h 3 min | 12 h 2 min | 15 h 3 min | 4 h | 2% |
| Sat Jul 3 | 15 h 2 min | 12 h 1 min | 15 h 2 min | 4 h | 0% |
| Sun Jul 4 | 15 h 1 min | 12 h | 15 h 1 min | 4 h | 2% |
| Mon Jul 5 | 14 h 59 min | 11 h 59 min | 13 h 37 min | 4 h | 6% |
| Tue Jul 6 | 14 h 58 min | 11 h 58 min | 11 h 58 min | 4 h | 13% |
| Wed Jul 7 | 14 h 56 min | 11 h 56 min | 10 h 24 min | 3 h 18 min | 22% |
| Thu Jul 8 | 14 h 55 min | 11 h 55 min | 8 h 55 min | 1 h 49 min | 32% |
| Fri Jul 9 | 14 h 53 min | 11 h 54 min | 7 h 28 min | 23 min | 43% |
| Sat Jul 10 | 14 h 51 min | 11 h 52 min | 6 h 3 min | 0 min | 54% |
| Sun Jul 11 | 14 h 50 min | 11 h 51 min | 4 h 38 min | 0 min | 64% |
| Mon Jul 12 | 14 h 48 min | 11 h 49 min | 3 h 16 min | 0 min | 74% |
| Tue Jul 13 | 14 h 46 min | 11 h 47 min | 2 h | 0 min | 82% |
| Wed Jul 14 | 14 h 44 min | 11 h 46 min | 54 min | 0 min | 89% |
| Thu Jul 15 | 14 h 42 min | 11 h 44 min | 3 min | 0 min | 94% |
| Fri Jul 16 | 14 h 39 min | 11 h 42 min | 0 min | 0 min | 98% |
| Sat Jul 17 | 14 h 37 min | 11 h 40 min | 0 min | 0 min | 100% |
| Sun Jul 18 | 14 h 35 min | 11 h 38 min | 0 min | 0 min | 100% |
| Mon Jul 19 | 14 h 32 min | 11 h 36 min | 29 min | 0 min | 98% |
| Tue Jul 20 | 14 h 30 min | 11 h 34 min | 1 h 43 min | 0 min | 95% |
| Wed Jul 21 | 14 h 27 min | 11 h 32 min | 2 h 56 min | 0 min | 90% |
| Thu Jul 22 | 14 h 25 min | 11 h 30 min | 4 h 8 min | 35 min | 83% |
| Fri Jul 23 | 14 h 22 min | 11 h 27 min | 5 h 21 min | 1 h 50 min | 75% |
| Sat Jul 24 | 14 h 19 min | 11 h 25 min | 6 h 37 min | 3 h 6 min | 66% |
| Sun Jul 25 | 14 h 17 min | 11 h 22 min | 7 h 56 min | 4 h | 56% |
| Mon Jul 26 | 14 h 14 min | 11 h 20 min | 9 h 20 min | 4 h | 46% |
| Tue Jul 27 | 14 h 11 min | 11 h 17 min | 10 h 46 min | 4 h | 35% |
| Wed Jul 28 | 14 h 8 min | 11 h 15 min | 12 h 9 min | 4 h | 25% |
| Thu Jul 29 | 14 h 5 min | 11 h 12 min | 13 h 17 min | 4 h | 16% |
| Fri Jul 30 | 14 h 2 min | 11 h 9 min | 14 h 2 min | 4 h | 8% |
| Sat Jul 31 | 13 h 59 min | 11 h 7 min | 13 h 59 min | 4 h | 3% |
Questions
- Can you see the southern lights in Ushuaia in July?
- On dark, clear nights with enough activity. 31 of 31 nights at Ushuaia have civil darkness.
- How dark is Ushuaia in July?
- Ushuaia averages 14.6 hours of civil night a night in July 2027, from 15 h 4 min on the 1st to 13 h 59 min on the last night.
- How cloudy is Ushuaia in July?
- NASA POWER's 2001 to 2020 climatology gives Ushuaia's 1 degree cell 72% mean cloud in July, against 78% for the whole year. It is an all-hours average, not a forecast.
- What is the best night in July 2027 for aurora in Ushuaia?
- By darkness and moon alone, Jul 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Ushuaia. Activity on that date will only be known hours ahead.
- Is July or August better in Ushuaia?
- By civil night times the clear share, July scores 4.1 hours at Ushuaia and August 3.1. July 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.