In the app
The Sun does more than shine: it blows a wind of particles that deforms Earth’s magnetic field. Almanaccolo shows its state in near real time.
It measures from 0 to 9 how disturbed Earth’s magnetic field is. Below 4 all is quiet. From 5 a geomagnetic storm begins: shortwave communications degrade and the aurora moves toward the equator. At Kp 7 it can become visible from northern Italy — it happened in May 2024.
A flare’s light arrives in eight minutes and immediately disturbs radio on the sunlit side. The cloud of particles that follows travels far slower: one to three days, and it is the one that lights the auroras.
| Kp | Class | Effects |
|---|---|---|
| 0–3 | Quiet | No effect. Normal HF propagation. |
| 4 | Unsettled | First disturbances at high latitudes. |
| 5 | G1 — minor | Aurora over Scandinavia and Scotland. |
| 6 | G2 — moderate | Aurora down to northern Germany. |
| 7 | G3 — strong | Aurora possible from northern Italy. HF difficult. |
| 8–9 | G4–G5 — severe | Risk to power grids and satellites. |
Data: NOAA SWPC
It measures from 0 to 9 how disturbed Earth's magnetic field is. Below 4 all is quiet; from 5 a geomagnetic storm begins, shortwave communications degrade and the aurora moves toward the equator.
It takes a Kp index around 7, a strong geomagnetic storm. It happened in May 2024, when the aurora was visible from northern Italy.
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Almanaccolo greets you each morning with the almanac of the day, sunrise and sunset times and your saved events.
