Bismarck · April 2027
Northern lights in Bismarck in April 2027
Answer
April against the rest of the year
April cloud at Bismarck averages 61% in NASA POWER's 2001 to 2020 record, 3 points cloudier than its yearly mean. July is Bismarck's clearest month at 44%. By civil night times clear sky, April scores 3.6 hours at Bismarck, 10th of 12. Fargo, 304 km away, averages the same 61%.
Civil night at Bismarck starts April at 10 h 1 min and reaches 8 h 22 min by April 30, 1.6 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 6.5 hours on the 15th.
April night by night
April opens toward a new moon on Apr 6, with full moon on Apr 20, in America/Chicago dates. Bismarck gets 145 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: Apr 1 (4 h), Apr 2 (4 h), Apr 3 (4 h).
- 1
22% lit
8.8 h
- 2
14% lit
9.1 h
- 3
8% lit
9.4 h
- 4
4% lit
9.6 h
- 5
1% lit
9.8 h
- 6
0% lit
9.7 h
- 7
2% lit
8.9 h
- 8
6% lit
7.5 h
- 9
12% lit
6.2 h
- 10
21% lit
5.0 h
- 11
31% lit
3.9 h
- 12
42% lit
3.0 h
- 13
53% lit
2.4 h
- 14
64% lit
1.9 h
- 15
75% lit
1.4 h
- 16
84% lit
1.1 h
- 17
91% lit
0.7 h
- 18
96% lit
0.4 h
- 19
99% lit
0.0 h
- 20
100% lit
0.0 h
- 21
98% lit
1.0 h
- 22
94% lit
2.2 h
- 23
89% lit
3.3 h
- 24
82% lit
4.2 h
- 25
74% lit
4.9 h
- 26
65% lit
5.5 h
- 27
56% lit
5.9 h
- 28
47% lit
6.2 h
- 29
37% lit
6.5 h
- 30
28% lit
6.8 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 Aprils
Bismarck needs Kp 6 for the average oval edge to sit overhead. 37 of the 900 April days from 1996 to 2025 (4%) reached it in the GFZ Potsdam record, 5th of 12 months; storm days with Kp 5 or more made up 12%. Bismarck sits at 54.7 degrees geomagnetic. The lowest NOAA storm level whose typical viewing latitude reaches it is G3 (Kp = 7). By SWPC's rule the average oval edge is overhead only at Kp 6.
April across United States
Bismarck ranks 4th in United States for civil night on April 15, behind Buffalo at 9.5 hours. Coming from March (11.0 hours at Bismarck), April loses darkness, and May brings shorter nights (7.6 hours on the 15th).
| Town | Civil night | Cloud |
|---|---|---|
| Buffalo | 9.5 h | 69% |
| Portland, Maine | 9.4 h | 62% |
| Minneapolis | 9.3 h | 61% |
| Bismarck | 9.2 h | 61% |
| Duluth | 9.2 h | 64% |
| Fargo | 9.2 h | 61% |
| Seattle | 9.1 h | 75% |
| Juneau | 7.9 h | 75% |
| Anchorage | 7.4 h | 72% |
| Eagle River | 7.4 h | 72% |
| Fairbanks | 6.6 h | 59% |
Darkness and moon, every night
| Night | Civil | Astronomical | Moon-free dark | Moon-free, 10 PM to 2 AM | Moon lit |
|---|---|---|---|---|---|
| Thu Apr 1 | 10 h 1 min | 7 h 30 min | 8 h 51 min | 4 h | 22% |
| Fri Apr 2 | 9 h 58 min | 7 h 26 min | 9 h 8 min | 4 h | 14% |
| Sat Apr 3 | 9 h 54 min | 7 h 22 min | 9 h 23 min | 4 h | 8% |
| Sun Apr 4 | 9 h 51 min | 7 h 17 min | 9 h 38 min | 4 h | 4% |
| Mon Apr 5 | 9 h 47 min | 7 h 13 min | 9 h 47 min | 4 h | 1% |
| Tue Apr 6 | 9 h 44 min | 7 h 9 min | 9 h 44 min | 4 h | 0% |
| Wed Apr 7 | 9 h 40 min | 7 h 5 min | 8 h 52 min | 4 h | 2% |
| Thu Apr 8 | 9 h 37 min | 7 h | 7 h 32 min | 2 h 59 min | 6% |
| Fri Apr 9 | 9 h 33 min | 6 h 56 min | 6 h 12 min | 1 h 41 min | 12% |
| Sat Apr 10 | 9 h 30 min | 6 h 52 min | 4 h 58 min | 29 min | 21% |
| Sun Apr 11 | 9 h 27 min | 6 h 47 min | 3 h 53 min | 0 min | 31% |
| Mon Apr 12 | 9 h 23 min | 6 h 43 min | 3 h 2 min | 0 min | 42% |
| Tue Apr 13 | 9 h 20 min | 6 h 39 min | 2 h 23 min | 0 min | 53% |
| Wed Apr 14 | 9 h 16 min | 6 h 34 min | 1 h 52 min | 0 min | 64% |
| Thu Apr 15 | 9 h 13 min | 6 h 30 min | 1 h 27 min | 0 min | 75% |
| Fri Apr 16 | 9 h 9 min | 6 h 25 min | 1 h 5 min | 0 min | 84% |
| Sat Apr 17 | 9 h 6 min | 6 h 21 min | 44 min | 0 min | 91% |
| Sun Apr 18 | 9 h 2 min | 6 h 16 min | 24 min | 0 min | 96% |
| Mon Apr 19 | 8 h 59 min | 6 h 12 min | 2 min | 0 min | 99% |
| Tue Apr 20 | 8 h 56 min | 6 h 7 min | 0 min | 0 min | 100% |
| Wed Apr 21 | 8 h 52 min | 6 h 3 min | 1 h | 16 min | 98% |
| Thu Apr 22 | 8 h 49 min | 5 h 58 min | 2 h 11 min | 1 h 27 min | 94% |
| Fri Apr 23 | 8 h 46 min | 5 h 53 min | 3 h 15 min | 2 h 33 min | 89% |
| Sat Apr 24 | 8 h 42 min | 5 h 49 min | 4 h 9 min | 3 h 29 min | 82% |
| Sun Apr 25 | 8 h 39 min | 5 h 44 min | 4 h 53 min | 4 h | 74% |
| Mon Apr 26 | 8 h 36 min | 5 h 39 min | 5 h 27 min | 4 h | 65% |
| Tue Apr 27 | 8 h 32 min | 5 h 35 min | 5 h 53 min | 4 h | 56% |
| Wed Apr 28 | 8 h 29 min | 5 h 30 min | 6 h 14 min | 4 h | 47% |
| Thu Apr 29 | 8 h 26 min | 5 h 25 min | 6 h 32 min | 4 h | 37% |
| Fri Apr 30 | 8 h 22 min | 5 h 20 min | 6 h 47 min | 4 h | 28% |
Questions
- Can you see the northern lights in Bismarck in April?
- On dark, clear nights with enough activity. 30 of 30 nights at Bismarck have civil darkness, and 4% of past April days reached Kp 6.
- How dark is Bismarck in April?
- Bismarck averages 9.2 hours of civil night a night in April 2027, from 10 h 1 min on the 1st to 8 h 22 min on the last night.
- How cloudy is Bismarck in April?
- NASA POWER's 2001 to 2020 climatology gives Bismarck's 1 degree cell 61% mean cloud in April, against 58% for the whole year. It is an all-hours average, not a forecast.
- What is the best night in April 2027 for aurora in Bismarck?
- By darkness and moon alone, Apr 1, with 4 h of moon-free darkness inside 10 PM to 2 AM at Bismarck. Activity on that date will only be known hours ahead.
- Is April or May better in Bismarck?
- By civil night times the clear share, April scores 3.6 hours at Bismarck and May 3.0. April 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.