Can you see the northern lights in South Dakota tonight?
Unlikely: Kp 1.33 at 4:21 PM CDT falls short of the Kp 4 or so that South Dakota's northern horizon requires.
as of
Kp now
1.33
South Dakota needs
Kp 4
Verdict
Unlikely
Sky tonight
Clear, 11% cloud
Moon tonight
40% lit, last quarter
Nautical darkness
Darkness 8:07 PM to 6:29 AM
Kp from NOAA SWPC estimated planetary K index. The NWS ABR gridded forecast provides cloud cover for Roy Lake State Park.
At Roy Lake State Park, nautical darkness begins at 8:07 PM and holds until 6:29 AM CDT. Tonight's moon, in its last quarter phase, shows 40 percent lit. The sun and moon positions, computed for the date and the viewing spot, supply both numbers, and no forecast plays a part.
What is Kp?
A 0-9 scale called Kp rates the current disturbance of Earth's magnetic field. Its name comes from planetarische Kennziffer, German for planetary index. Thirteen observatories worldwide take the measurements. Higher values mean the aurora reaches further south. Most of the northern US needs a Kp of 5 or higher, while northern Alaska sees it at Kp 0. Full Kp guide.
Why South Dakota needs Kp 4
Because the aurora follows the magnetic field rather than the equator, geomagnetic latitude matters more than map latitude. At South Dakota's northern edge, the reading is 54.0° geomagnetic; the oval only draws level with that latitude at about Kp 4, and the Kp number already includes roughly 5 degrees of cushion, because the high-altitude aurora hangs low on the horizon.
Where to watch from in South Dakota
All three spots in South Dakota can differ in cloud cover, so all three are worth a look. Custer State Park, Sylvan Lake looks clearest tonight, at 4% cover.
| Spot | Cloud tonight | Clearest hour | Nearest town |
|---|---|---|---|
| Roy Lake State Park | 11% Clear | 12:00 AM CDT | Lake City |
| Sica Hollow State Park | 9% Clear | 12:00 AM CDT | Long Hollow |
| Custer State Park, Sylvan Lake | 4% Clear | 10:00 PM MDT | Hill City |
South Dakota sees aurora on many nights, and Roy Lake State Park near Lake City is a good dark site. Sica Hollow State Park near Long Hollow and Custer State Park's Sylvan Lake near Hill City offer more options. Equinox peaks are strong, and dark nights run October to March.
Can the northern lights reach Rapid City and Sioux Falls tonight?
| City | Kp needed | Right now |
|---|---|---|
| Rapid City | Kp 5 | No chance |
| Sioux Falls | Kp 5 | No chance |
Each city's Kp value comes from its own coordinates and geomagnetic latitude, so the further south a city is in the state, the higher the Kp it needs.
Cloud cover, averaged over tonight's viewing window for each location, comes from NWS gridded forecasts.
Was there aurora last night in South Dakota?
The night of October 3 topped out at Kp 3.00, short of the 4 South Dakota needs, so the aurora stayed out of range.
The most recent night in range was September 7, 2026, when the night's highest Kp reached 4.33.
57 nights so far in 2026 have been in range for South Dakota, against a yearly average of 63.7 across the complete years since 1994. The year's highest night Kp so far is 8.67, set on January 19, 2026.
Nights in range by year in South Dakota
| Year | Nights in range | Highest Kp | Peak date |
|---|---|---|---|
| 2026 2026 is not over | 57 | 8.67 | Jan 19, 2026 |
| 2025 | 109 | 8.67 | Nov 11, 2025 |
| 2024 | 57 | 9.00 | May 10, 2024 |
| 2023 | 69 | 7.67 | Apr 23, 2023 |
| 2022 | 77 | 6.00 | Jan 14, 2022 |
| 2021 | 54 | 7.00 | Nov 3, 2021 |
| 2020 | 20 | 6.00 | Sep 27, 2020 |
| 2019 | 35 | 5.00 | Jan 4, 2019 |
| 2018 | 53 | 6.00 | Mar 18, 2018 |
| 2017 | 86 | 8.00 | Sep 7, 2017 |
| 2016 | 100 | 7.00 | Mar 6, 2016 |
| 2015 | 87 | 8.00 | Mar 17, 2015 |
Local time 9 pm to 3 am is the span of a night. The night's Kp is the highest among the three hour windows overlapping those hours. A night is in range when that Kp reached the threshold the state needs, which comes from where the northern edge of the state sits in geomagnetic latitude. Cloud is not in the record, so in range means the aurora was in range, not that anyone saw it. Figures are NOAA Space Weather Prediction Center daily geomagnetic data from 1994 on.
The next three days
NOAA's three-hour Kp outlook. At the highest expected value of Kp 5.00, the aurora would come into range for South Dakota.
| Day | Local window | Kp | In range |
|---|---|---|---|
| Oct 3 | 7 PM to 10 PM CDT00-03UT | 3.00 | No |
| Oct 3 | 10 PM to 1 AM CDT03-06UT | 3.33 | No |
| Oct 4 | 1 AM to 4 AM CDT06-09UT | 4.33 | Yes |
| Oct 4 | 4 AM to 7 AM CDT09-12UT | 5.00 | Yes |
| Oct 4 | 7 AM to 10 AM CDT12-15UT | 4.00 | Yes |
| Oct 4 | 10 AM to 1 PM CDT15-18UT | 3.67 | No |
| Oct 4 | 1 PM to 4 PM CDT18-21UT | 4.67 | Yes |
| Oct 4 | 4 PM to 7 PM CDT21-00UT | 3.00 | No |
| Oct 4 | 7 PM to 10 PM CDT00-03UT | 3.33 | No |
| Oct 4 | 10 PM to 1 AM CDT03-06UT | 4.33 | Yes |
| Oct 5 | 1 AM to 4 AM CDT06-09UT | 3.33 | No |
| Oct 5 | 7 AM to 10 AM CDT12-15UT | 2.67 | No |
| Oct 5 | 10 AM to 1 PM CDT15-18UT | 1.67 | No |
| Oct 5 | 4 PM to 7 PM CDT21-00UT | 3.00 | No |
| Oct 5 | 7 PM to 10 PM CDT00-03UT | 3.33 | No |
| Oct 5 | 10 PM to 1 AM CDT03-06UT | 3.67 | No |
| Oct 6 | 1 AM to 4 AM CDT06-09UT | 3.00 | No |
| Oct 6 | 4 AM to 7 AM CDT09-12UT | 3.00 | No |
| Oct 6 | 7 AM to 10 AM CDT12-15UT | 2.33 | No |
| Oct 6 | 10 AM to 1 PM CDT15-18UT | 2.00 | No |
| Oct 6 | 1 PM to 4 PM CDT18-21UT | 2.00 | No |
| Oct 6 | 4 PM to 7 PM CDT21-00UT | 1.67 | No |
NOAA Space Weather Prediction Center three-day forecast, issued 2026 Oct 04 1230 UTC.
The next 27 days
The NOAA Space Weather Prediction Center outlook puts 7 of the next 27 days at or above Kp 4.
This Kp outlook is issued by the NOAA Space Weather Prediction Center at 2026 Sep 28 0221 UTC.
Watching from South Dakota
- The aurora seldom appears overhead in South Dakota; look at the northern horizon instead.
- Away from town lights, allow 20 minutes for your eyes to adjust.
- The aurora is most active from 10pm to 2am local, near magnetic midnight.
- A phone exposure of 3-5 seconds picks up color the eye cannot; a grey glow can photograph green.
Compare every state, ranked right now
The NOAA Space Weather Prediction Center produces the Kp readings and aurora forecasts on this page. As US government works, they are not subject to copyright under 17 U.S.C. 105; this notice is the notice required by 17 U.S.C. 403. Mention of the center does not imply endorsement or affiliation; for attribution, see Data sources and attribution.