Space Weather
Kp Index — live and explained
Explanations by Spaceweathertracker staff · Last reviewed · Editorial standards · About
The last observed planetary Kp index is 1.3 (G0 — no storm) as of Nov 5, 2026, 09:00 UTC, per NOAA Space Weather Prediction Center.
Last Observed Kp
Updated every 10 minutes from live NOAA data.
NOAA observation: Nov 5, 2026, 09:00 UTCPage verified: Nov 5, 2026, 13:20 UTC
Source: NOAA SWPC
Storm Level
Aurora activity: Quiet
Why it matters
Kp is the single most useful number for predicting aurora visibility — it directly maps to how far from the poles the aurora oval expands. It's also the basis for NOAA's official G-scale geomagnetic storm classification, which utilities, satellite operators, and airlines use to anticipate real-world impacts like power grid stress, satellite drag, and radio disruption.
Normal range
Kp 0-2 is quiet, typical for most days. Kp 3-4 is unsettled but still common. Kp 5+ (G1 storm or higher) is where aurora becomes visible outside the polar regions, and happens on a meaningful minority of nights, more often near solar maximum. Kp 8-9 (G4-G5, extreme) is rare — a handful of times per solar cycle.
What today's value means
Right now Kp is 1.3 (G0 — No storm). This is within the normal quiet-to-unsettled range — aurora is likely confined to high latitudes.
What is the Kp index?
The planetary K-index (Kp) is a 0-to-9 scale measuring geomagnetic disturbance, calculated from magnetometer readings at observatories spread across the globe. It's published by NOAA's Space Weather Prediction Center and updated every three hours from ground stations, while this page re-checks the reporting feed separately. The displayed timestamp is the source interval, not the page refresh time. A quiet day sits around Kp 0-2; a major geomagnetic storm can push Kp to 8 or 9.
Kp level and aurora visibility
| Kp | G-Scale | Level | Typical aurora visibility |
|---|---|---|---|
| 0–2 | — | Quiet | Aurora remains possible at high magnetic latitudes. |
| 3–4 | — | Unsettled | Minor activity; aurora confined to high latitudes (Alaska, northern Canada, Scandinavia). |
| 5 | G1 | Minor storm | Aurora may become visible from the northern-tier US states and similar latitudes. |
| 6 | G2 | Moderate storm | Aurora visibility pushes further south, into the upper Midwest and Northeast. |
| 7 | G3 | Strong storm | Aurora can reach mid-latitude states. |
| 8–9 | G4–G5 | Severe–Extreme storm | Rare events; aurora can be visible as far south as the southern US. |
Actual visibility also depends on cloud cover, moonlight, and local light pollution — check the aurora forecast for your specific location.
NOAA G-scale reference
NOAA's official geomagnetic storm scale, G1 (Minor) to G5 (Extreme), published by the Space Weather Prediction Center.
| G-Scale | Level | Kp | Aurora latitude | Power grid / satellite effects |
|---|---|---|---|---|
| G1 | Minor | 5 | ~60° | Weak power grid fluctuations; minor impact on satellite operations. |
| G2 | Moderate | 6 | ~55° | High-latitude power systems may see voltage alarms; corrective action may be needed. |
| G3 | Strong | 7 | ~50° | Voltage corrections may be required; false alarms on some grid protection devices. |
| G4 | Severe | 8 | ~45° | Widespread voltage control problems possible; some protective systems may mistakenly trip. |
| G5 | Extreme | 9 | ~40° | Widespread voltage control problems; grid systems may experience complete collapse or blackouts; transformers may be damaged. |
Recent history
The last 24 hours of observed Kp values from this site's live feed.
Kp forecast: next 3 days and 27-day outlook
NOAA's forecast of the planetary Kp for each 3-hour interval (UTC) of the next three days, and its 27-day outlook of radio flux, Ap and the largest expected Kp. Forecast values are predictions, not observations.
3-day planetary Kp forecast
NOAA SWPC 3-day Kp forecast (3-hour intervals)
27-day outlook
A qualitative long-range outlook of solar radio flux, geomagnetic Ap and the largest expected Kp — useful for trend, not for precise day-by-day prediction.
NOAA SWPC 27-day outlook
Planetary Kp or one observatory?
The number at the top of this page is the planetary Kp (Kpp): NOAA's estimated 3-hour index combined from magnetometers around the world, so it describes the whole planet. A single ground observatory, such as the Boulder, Colorado magnetometer, measures only its own local disturbance and can read higher or lower than the planetary value. Local readings are on the live dashboard.
Kp and aurora latitude: where the viewline sits
Latitudes are geomagnetic, not geographic: the magnetic pole is offset from the geographic one, so a place's geomagnetic latitude is usually a few degrees different from its map latitude (in the continental US it is lower, so you need a stronger storm than the map latitude suggests). "Overhead" is the approximate equatorward edge of the auroral oval; "on the horizon" is about 8° farther equatorward, where a strong display shows low on the northern sky.
| Kp | NOAA G-scale | Aurora overhead from | Aurora on the horizon from |
|---|---|---|---|
| 0 | no storm | ~66.5° geomagnetic | ~58.5° geomagnetic |
| 1 | no storm | ~64.5° geomagnetic | ~56.5° geomagnetic |
| 2 | no storm | ~62.4° geomagnetic | ~54.4° geomagnetic |
| 3 | no storm | ~60.4° geomagnetic | ~52.4° geomagnetic |
| 4 | no storm | ~58.3° geomagnetic | ~50.3° geomagnetic |
| 5 | G1 | ~56.3° geomagnetic | ~48.3° geomagnetic |
| 6 | G2 | ~54.2° geomagnetic | ~46.2° geomagnetic |
| 7 | G3 | ~52.2° geomagnetic | ~44.2° geomagnetic |
| 8 | G4 | ~50.1° geomagnetic | ~42.1° geomagnetic |
| 9 | G5 | ~48.1° geomagnetic | ~40.1° geomagnetic |
NOAA's scale: Kp 5 = G1 (minor), Kp 6 = G2, Kp 7 = G3, Kp 8 = G4, Kp 9 = G5 (extreme). Oval edge values follow the standard Starkov (1994) auroral-oval model and are approximate; the live oval moves with conditions. See the aurora forecast for your location.
Kp alone does not tell you if aurora will appear
Kp is an average over three hours, so it lags what is happening now. Whether aurora actually lights up depends on the solar wind right now: a southward IMF Bz (negative values) opens Earth's magnetic field to the solar wind, and a fast solar wind (about 500 km/s or more) adds energy. A high Kp with a northward Bz can disappoint, and a modest Kp with a strongly southward Bz can surprise. Check IMF Bz and solar wind speed alongside Kp.
FAQ
What Kp level do I need to see the aurora?
Kp 5 or higher (G1) typically brings aurora into view from the far northern US. Kp 7+ (G3) can push it into mid-latitude states, and Kp 8-9 (G4-G5) are rare events capable of bringing aurora as far south as the southern US.
How often does the Kp index update?
Kp describes three-hour reporting intervals. This page re-checks the source separately; refreshing the page does not create a new observation.
What's the highest Kp ever recorded?
Kp is capped at 9, the maximum on the scale — reached only during the most extreme geomagnetic storms, such as the May 2024 and October 2003 storms.
Sources
- Planetary K-index — NOAA SWPC — Kp is an integer 0–9; 5 or more indicates a geomagnetic storm.
- NOAA Space Weather Scales (G, S and R) — NOAA SWPC — Official G1–G5, S1–S5 and R1–R5 definitions and average frequency per solar cycle.
- Geomagnetic Storms — NOAA SWPC — How CMEs and solar wind drive storms and the Kp-based G-scale.
- G5 Conditions Observed! — NOAA SWPC (10 May 2024) — NOAA's notice that G5 (Extreme) conditions reached Earth on 10 May 2024.
- Five historically huge solar events — NOAA — Carrington Event (1859), 2003 Halloween storms and the May 2024 G5 storm.