Kp Index Today
Live geomagnetic activity and what it means for the aurora.
Pick your place to see the Kp it needs, marked on the chart.
Kp index now
Kp index
Kp shows how disturbed Earth’s magnetic field is, from 0 to 9. The higher it goes, the brighter the aurora and the further from the poles you can see it.
Status levels
-
Storm
Kp 5 to 9 (G1 to G5): Geomagnetic storm. Bright, fast-moving aurora that can reach far south.
-
Active
Kp 4: Good conditions. Can reach southern Canada, Scotland and the northern US border.
-
Unsettled
Kp 3: Some activity. Common in Alaska, northern Canada, Iceland and northern Scandinavia.
-
Quiet
Kp 0 to 2: Low activity. Fainter aurora, mostly close to the Arctic Circle.
0.7
Quiet
Storm level: None
Max next 24 h: 3.7
Kp Index Forecast, 3-Hour Blocks (your local time)
Faded = observed · solid = forecast
| Time | Kp | Type |
|---|---|---|
| Wed, Nov 4 12:00 | 3.0 | observed |
| Wed, Nov 4 15:00 | 1.0 | observed |
| Wed, Nov 4 18:00 | 1.7 | observed |
| Wed, Nov 4 21:00 | 1.3 | observed |
| Thu, Nov 5 00:00 | 2.7 | forecast |
| Thu, Nov 5 03:00 | 2.7 | forecast |
| Thu, Nov 5 06:00 | 3.0 | forecast |
| Thu, Nov 5 09:00 | 2.7 | forecast |
| Thu, Nov 5 12:00 | 2.7 | forecast |
| Thu, Nov 5 15:00 | 1.7 | forecast |
| Thu, Nov 5 18:00 | 1.7 | forecast |
| Thu, Nov 5 21:00 | 3.7 | forecast |
| Fri, Nov 6 00:00 | 2.3 | forecast |
| Fri, Nov 6 03:00 | 2.0 | forecast |
| Fri, Nov 6 06:00 | 2.0 | forecast |
| Fri, Nov 6 09:00 | 2.3 | forecast |
| Fri, Nov 6 12:00 | 2.3 | forecast |
| Fri, Nov 6 15:00 | 3.7 | forecast |
| Fri, Nov 6 18:00 | 4.0 | forecast |
| Fri, Nov 6 21:00 | 4.7 | forecast |
| Sat, Nov 7 00:00 | 5.0 | forecast |
| Sat, Nov 7 03:00 | 3.7 | forecast |
| Sat, Nov 7 06:00 | 3.3 | forecast |
| Sat, Nov 7 09:00 | 3.3 | forecast |
Status levels
Kp shows how disturbed Earth’s magnetic field is, from 0 to 9. The higher it goes, the brighter the aurora and the further from the poles you can see it.
-
Storm
Kp 5 to 9 (G1 to G5): Geomagnetic storm. Bright, fast-moving aurora that can reach far south.
-
Active
Kp 4: Good conditions. Can reach southern Canada, Scotland and the northern US border.
-
Unsettled
Kp 3: Some activity. Common in Alaska, northern Canada, Iceland and northern Scandinavia.
-
Quiet
Kp 0 to 2: Low activity. Fainter aurora, mostly close to the Arctic Circle.
- Faded bars are already measured. Bright bars are the forecast.
- The dashed line is the Kp needed where you are. Bars that reach it are your chances.
What you need to see the lights
- Kp at or above the level needed where you are. The further from the Arctic, the higher it has to be.
- A dark sky: the sun at least 12° below the horizon, so not in summer near the Arctic.
- Clear skies. Clouds block the aurora however strong it is.
- Get away from city lights, look north (south in the southern hemisphere), and give your eyes 15 to 20 minutes.
Updated 02:20 · Source: NOAA SWPC
The Kp index measures how disturbed Earth’s magnetic field is, on a scale from 0 (quiet) to 9 (extreme storm). Higher Kp pushes the aurora further from the poles. Below you will find today’s live Kp, the forecast for the next three days, and the Kp needed to see the aurora where you are.
How to Read the Kp Index
The big number is the latest estimated planetary Kp, updated every minute by NOAA. The chart below shows Kp in three-hour blocks: faded bars are observed values, solid bars are the forecast.
Kp uses thirds: 4.33 is written 4+, 4.67 is 5−. NOAA counts 5− and above as a G1 geomagnetic storm. Colours on the chart follow that scale: grey for quiet, violet for unsettled, yellow for active, and green for storm levels.
If you set a location on the forecast, the dashed line shows the Kp needed there. Any bar that crosses the line is a window when aurora could reach your sky, if it is dark and clear.
What Kp Do You Need to See the Northern Lights?
What matters is your geomagnetic latitude, your distance from the magnetic pole rather than the geographic one. The table below shows how far the aurora oval reaches for each Kp. At that geomagnetic latitude the aurora can be overhead; a few degrees further away it may still show low on the horizon.
Examples: Tromsø and Fairbanks need Kp 0–1. Reykjavík needs about Kp 0, Edmonton about Kp 4, Inverness about Kp 4, Marquette (Michigan) about Kp 6, Seattle about Kp 6, and Chicago about Kp 8. These are guides: strong substorms can beat them, and clouds can ruin a perfect Kp.
Kp is a three-hour global average, so it can lag behind sudden changes. For the next hour, live solar wind speed and a southward Bz on the space weather page often tell you more.
Kp Index Tips for Aurora Hunters
Do not chase a number alone. To see which places reach their Kp tonight, check the live ranking of where to see the northern lights tonight. A Kp of 3 with clear, dark skies in the Arctic beats a Kp of 6 under clouds. Always check cloud cover and darkness in the hourly forecast.
Kp forecasts more than 24 hours ahead are uncertain. NOAA forecasts storms from coronal mass ejections, but the arrival time can be off by many hours and the strength depends on the magnetic field direction when it arrives.
When NOAA issues a G1 or higher watch, we show a storm banner on every page. Set an aurora alert to be notified when your place reaches a good chance.
Kp Needed by Geomagnetic Latitude
| Kp | Storm level | Oval reaches (geomag. lat.) |
|---|---|---|
| 0 | None | 66.5° |
| 1 | None | 64.5° |
| 2 | None | 62.4° |
| 3 | None | 60.4° |
| 4 | None | 58.3° |
| 5 | G1 (Minor) | 56.3° |
| 6 | G2 (Moderate) | 54.2° |
| 7 | G3 (Strong) | 52.2° |
| 8 | G4 (Severe) | 50.1° |
| 9 | G5 (Extreme) | 48.1° |
| Place | Geomag. lat. | Kp needed |
|---|---|---|
| Tromsø, Norway | 67.5° | 0 |
| Fairbanks, Alaska | 65.7° | 1 |
| Reykjavík, Iceland | 68.8° | 0 |
| Yellowknife, Northwest Territories | 68.5° | 0 |
| Edmonton, Alberta | 60° | 4 |
| Inverness, Scotland | 59.8° | 4 |
| Marquette, Michigan | 55.4° | 6 |
| Seattle, Washington | 53° | 7 |
| London, England | 53.4° | 7 |
| Chicago, Illinois | 50.7° | 8 |
Frequently Asked Questions
What is the Kp index?
A 0–9 measure of global geomagnetic disturbance, calculated every three hours from magnetometers around the world. Higher Kp means the aurora reaches further from the poles.
What does Kp 5 mean?
Kp 5 is a G1 (minor) geomagnetic storm. The aurora can reach southern Canada, the northern US border states, Scotland, and southern Scandinavia under clear dark skies.
What Kp do I need to see the northern lights?
It depends on your geomagnetic latitude: about Kp 0–2 in the Arctic, Kp 3–5 in southern Canada and Scotland, Kp 6–7 along the northern US, and Kp 8–9 for the central US and southern Europe.
What is the Kp index today?
The live value is shown at the top of this page and refreshes every five minutes from NOAA’s one-minute estimated Kp.
How far ahead can Kp be forecast?
NOAA issues a three-day forecast in three-hour blocks and a rough 27-day outlook. The first 24 hours are the most reliable.
What is the difference between Kp and the G-scale?
The G-scale is NOAA’s storm category derived from Kp: G1 = Kp 5, G2 = Kp 6, G3 = Kp 7, G4 = Kp 8, G5 = Kp 9.
Related
Data: NOAA Space Weather Prediction Center and MET Norway. Updated every 5 minutes. Data sources