Ushuaia · May 2027
Southern lights in Ushuaia in May 2027
Answer
May against the rest of the year
May cloud at Ushuaia averages 73% in NASA POWER's 2001 to 2020 record, 5 points clearer than its yearly mean. July is Ushuaia's clearest month at 72%. By civil night times clear sky, May scores 3.8 hours at Ushuaia, 3rd of 12. Buffalo, 10,909 km away, averages 65%, clearer by 8 points.
Civil night at Ushuaia starts May at 13 h 25 min and reaches 14 h 50 min by May 31 as the nights lengthen by 1.4 hours. SWPC's 10 PM to 2 AM window is fully dark on every night. True astronomical darkness, the sun 18 degrees down, lasts 11.3 hours on the 15th.
May night by night
May opens toward a new moon on May 6, with full moon on May 20, in America/Argentina/Ushuaia dates. Ushuaia gets 220 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: May 1 (4 h), May 2 (4 h), May 3 (4 h).
- 1
20% lit
9.3 h
- 2
13% lit
10.7 h
- 3
7% lit
12.1 h
- 4
2% lit
13.6 h
- 5
0% lit
13.7 h
- 6
1% lit
13.7 h
- 7
4% lit
13.8 h
- 8
10% lit
13.8 h
- 9
17% lit
12.7 h
- 10
27% lit
11.3 h
- 11
38% lit
9.7 h
- 12
49% lit
8.2 h
- 13
61% lit
6.7 h
- 14
71% lit
5.3 h
- 15
80% lit
4.0 h
- 16
88% lit
2.6 h
- 17
94% lit
1.2 h
- 18
98% lit
0.0 h
- 19
100% lit
0.0 h
- 20
99% lit
0.0 h
- 21
97% lit
0.0 h
- 22
93% lit
0.2 h
- 23
88% lit
1.3 h
- 24
81% lit
2.6 h
- 25
73% lit
3.9 h
- 26
64% lit
5.1 h
- 27
55% lit
6.4 h
- 28
45% lit
7.7 h
- 29
35% lit
8.9 h
- 30
26% lit
10.3 h
- 31
17% lit
11.7 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 Mays
No whole Kp puts the average oval edge over Ushuaia by SWPC's rule, so the GFZ record has no threshold to count for May. 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.
May across Argentina
Coming from April (12.4 hours at Ushuaia), May adds darkness, and the nights keep growing into June (15.1 hours on the 15th).
Darkness and moon, every night
| Night | Civil | Astronomical | Moon-free dark | Moon-free, 10 PM to 2 AM | Moon lit |
|---|---|---|---|---|---|
| Sat May 1 | 13 h 25 min | 10 h 36 min | 9 h 20 min | 4 h | 20% |
| Sun May 2 | 13 h 29 min | 10 h 39 min | 10 h 41 min | 4 h | 13% |
| Mon May 3 | 13 h 32 min | 10 h 42 min | 12 h 6 min | 4 h | 7% |
| Tue May 4 | 13 h 36 min | 10 h 46 min | 13 h 35 min | 4 h | 2% |
| Wed May 5 | 13 h 39 min | 10 h 49 min | 13 h 39 min | 4 h | 0% |
| Thu May 6 | 13 h 43 min | 10 h 52 min | 13 h 43 min | 4 h | 1% |
| Fri May 7 | 13 h 46 min | 10 h 55 min | 13 h 46 min | 4 h | 4% |
| Sat May 8 | 13 h 49 min | 10 h 58 min | 13 h 49 min | 4 h | 10% |
| Sun May 9 | 13 h 53 min | 11 h 1 min | 12 h 43 min | 4 h | 17% |
| Mon May 10 | 13 h 56 min | 11 h 4 min | 11 h 16 min | 4 h | 27% |
| Tue May 11 | 13 h 59 min | 11 h 7 min | 9 h 43 min | 3 h 14 min | 38% |
| Wed May 12 | 14 h 2 min | 11 h 10 min | 8 h 12 min | 1 h 41 min | 49% |
| Thu May 13 | 14 h 5 min | 11 h 12 min | 6 h 44 min | 11 min | 61% |
| Fri May 14 | 14 h 8 min | 11 h 15 min | 5 h 19 min | 0 min | 71% |
| Sat May 15 | 14 h 11 min | 11 h 18 min | 3 h 57 min | 0 min | 80% |
| Sun May 16 | 14 h 14 min | 11 h 20 min | 2 h 34 min | 0 min | 88% |
| Mon May 17 | 14 h 17 min | 11 h 23 min | 1 h 11 min | 0 min | 94% |
| Tue May 18 | 14 h 20 min | 11 h 25 min | 0 min | 0 min | 98% |
| Wed May 19 | 14 h 22 min | 11 h 27 min | 0 min | 0 min | 100% |
| Thu May 20 | 14 h 25 min | 11 h 30 min | 0 min | 0 min | 99% |
| Fri May 21 | 14 h 28 min | 11 h 32 min | 0 min | 0 min | 97% |
| Sat May 22 | 14 h 30 min | 11 h 34 min | 14 min | 0 min | 93% |
| Sun May 23 | 14 h 33 min | 11 h 36 min | 1 h 20 min | 0 min | 88% |
| Mon May 24 | 14 h 35 min | 11 h 38 min | 2 h 34 min | 0 min | 81% |
| Tue May 25 | 14 h 37 min | 11 h 40 min | 3 h 51 min | 3 min | 73% |
| Wed May 26 | 14 h 40 min | 11 h 42 min | 5 h 8 min | 1 h 18 min | 64% |
| Thu May 27 | 14 h 42 min | 11 h 44 min | 6 h 24 min | 2 h 33 min | 55% |
| Fri May 28 | 14 h 44 min | 11 h 46 min | 7 h 39 min | 3 h 48 min | 45% |
| Sat May 29 | 14 h 46 min | 11 h 48 min | 8 h 57 min | 4 h | 35% |
| Sun May 30 | 14 h 48 min | 11 h 49 min | 10 h 17 min | 4 h | 26% |
| Mon May 31 | 14 h 50 min | 11 h 51 min | 11 h 42 min | 4 h | 17% |
Questions
- Can you see the southern lights in Ushuaia in May?
- On dark, clear nights with enough activity. 31 of 31 nights at Ushuaia have civil darkness.
- How dark is Ushuaia in May?
- Ushuaia averages 14.2 hours of civil night a night in May 2027, from 13 h 25 min on the 1st to 14 h 50 min on the last night.
- How cloudy is Ushuaia in May?
- NASA POWER's 2001 to 2020 climatology gives Ushuaia's 1 degree cell 73% mean cloud in May, against 78% for the whole year. It is an all-hours average, not a forecast.
- What is the best night in May 2027 for aurora in Ushuaia?
- By darkness and moon alone, May 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 May or June better in Ushuaia?
- By civil night times the clear share, May scores 3.8 hours at Ushuaia and June 4.1. June 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.