Solar Activity & Aviation
Space Weather Data (2025–2026)
Solar Cycle 25 reached its predicted peak in the 2024–2025 window. Geomagnetic activity has been elevated compared to the preceding decade, with measurable operational impact on polar aviation — HF communications outages, GNSS degradation, and advisory-driven reroutings. This page aggregates the publicly available operational data.
What Is Solar Cycle 25?
The Sun's activity cycles on an approximately 11-year period. Solar Cycle 25 started in December 2019 and reached its maximum phase in 2024–2025. During solar maximum, sunspot count, flare frequency, and coronal mass ejection (CME) rate all rise. Energetic events that reach Earth disturb the ionosphere and, in the most intense cases, trigger geomagnetic storms.
NOAA's G-scale (G1 minor to G5 extreme) classifies geomagnetic storms. G3 and above typically produce measurable aviation impact, especially at high latitude. G5 events are rare and historically cause extended HF radio blackouts and GNSS disruption.
Notable Events 2024–2026
| Date | NOAA G-Scale | Aviation-relevant impact |
|---|---|---|
| May 2024 | G5 | "Gannon storm" — extensive polar HF outages, widespread GNSS scintillation. Polar routings were rerouted or substantially delayed by multiple carriers. |
| Oct 2024 | G4 | Multiple-day disturbance affected northern trans-Atlantic and polar operations. FAA and NavCanada issued space weather advisories. |
| Feb 2025 | G4 | Enhanced high-latitude scintillation over several days. Some polar operators took southern reroute options on affected segments. |
| May 2025 | G5 | Second extreme event of Cycle 25. HF communication blackouts on polar tracks; several sector cancellations reported. |
| Nov 2025 | G3 | Short-duration but high-intensity CME impact. Some polar NOTAMs issued warning of expected GNSS degradation. |
| Feb 2026 | G4 | Sustained disturbance coinciding with Gulf airspace event period; complicated contingency planning for carriers already on reroute. |
| Mar 2026 | G5 | Third extreme event of Cycle 25. Polar reroutings for approximately 36 hours; HF replaced with satcom-only on affected sectors. |
How Does Space Weather Affect Aviation?
Polar HF radio depends on ionospheric reflection. Solar flares cause sudden ionospheric disturbances (SID) that absorb HF signals — "shortwave fadeout". During severe events, polar HF is unusable for hours. Aircraft switch to satcom data/voice. Operators must maintain a working secondary communications means for polar dispatch.
Ionospheric scintillation disturbs GNSS signal coherence. At polar latitudes the effect is more pronounced. Receivers may lose lock on individual satellites; integrity monitors flag increased uncertainty in the position fix. Multi-constellation receivers partially mitigate. IRS-primary operations remain unaffected.
Solar proton events (SPE) increase the radiation dose at high altitude and high latitude. Polar-qualified aircraft have radiation monitoring. During severe events, flight deck dosimeter readings can prompt descent to lower altitude as a precaution. Passenger doses remain well below regulatory limits even during severe events.
Carriers pre-plan contingency routings for severe space weather. NOAA SWPC forecasts and ICAO Space Weather advisories are inputs. Decisions to reroute to lower latitude are made by operator-side space weather teams coordinating with dispatch and OCC.
Source Categories
This page aggregates publicly available data from:
- NOAA Space Weather Prediction Center (SWPC) event archives
- ICAO Space Weather Advisory publications (issued by designated SWXC centres)
- NavCanada and FAA polar operations advisories
- Aviation press reporting on specific space-weather-driven rerouting events
- EASA and operator-published space weather procedures
Data aggregated from publicly available sources. Figures are reference context and may be updated as additional disclosures are published. See Terms of Service.