A strong X1.1 solar flare, classified as an R3 (Strong) radio blackout event, occurred on June 30, 2026, impacting high-frequency radio communications across large portions of Earth's sunlit side. The event began at 20:34 UTC, reached its maximum intensity at 20:50 UTC, and concluded by 21:00 UTC.
The X-ray event, originating from location N18W18 on the sun, caused a wide-area blackout of HF radio communication for approximately one hour. The strongest impacts were felt at the sub-solar point, affecting various communication systems reliant on high-frequency bands.