What does this number mean?
GOES satellites measure the Sun's soft X-ray brightness. The familiar A, B, C, M, and X classes increase by factors of ten; a larger class means stronger X-ray emission.
MCARC · Free amateur radio tools
GOES X-Ray Flux & Solar Flare History
GOES satellites monitor soft X-rays from the Sun. Compare recent flare activity on a logarithmic chart and learn how stronger flares can affect HF radio paths on Earth's sunlit side.NOAA observed readings
GOES X-Ray
Latest graphed reading: M1.4 (1.45e-5 W/m²) on Nov 7, 2026, 12:15 PM EST.
NOAA reading
View readings as a table
| Date and time (Eastern) | GOES X-Ray |
|---|---|
| Nov 7, 12:15 PM EST | M1.4 (1.45e-5 W/m²) |
| Nov 7, 12:00 PM EST | C3.5 (3.52e-6 W/m²) |
| Nov 7, 11:45 AM EST | C5.0 (4.96e-6 W/m²) |
| Nov 7, 11:30 AM EST | C4.3 (4.27e-6 W/m²) |
| Nov 7, 11:15 AM EST | C1.2 (1.22e-6 W/m²) |
| Nov 7, 11:00 AM EST | B8.3 (8.33e-7 W/m²) |
| Nov 7, 10:45 AM EST | C1.2 (1.16e-6 W/m²) |
| Nov 7, 10:30 AM EST | C1.2 (1.16e-6 W/m²) |
| Nov 7, 10:15 AM EST | C1.6 (1.64e-6 W/m²) |
| Nov 7, 10:00 AM EST | B9.3 (9.28e-7 W/m²) |
| Nov 7, 9:45 AM EST | C1.9 (1.88e-6 W/m²) |
| Nov 7, 9:30 AM EST | C1.6 (1.61e-6 W/m²) |
| Nov 7, 9:15 AM EST | C1.1 (1.12e-6 W/m²) |
| Nov 7, 9:00 AM EST | C1.3 (1.31e-6 W/m²) |
| Nov 7, 8:45 AM EST | C1.2 (1.16e-6 W/m²) |
| Nov 7, 8:30 AM EST | C1.6 (1.61e-6 W/m²) |
| Nov 7, 8:15 AM EST | C1.6 (1.63e-6 W/m²) |
| Nov 7, 8:00 AM EST | C1.6 (1.60e-6 W/m²) |
| Nov 7, 7:45 AM EST | M1.1 (1.08e-5 W/m²) |
| Nov 7, 7:30 AM EST | M1.3 (1.29e-5 W/m²) |
| Nov 7, 7:15 AM EST | C2.3 (2.27e-6 W/m²) |
| Nov 7, 7:00 AM EST | C5.7 (5.70e-6 W/m²) |
| Nov 7, 6:45 AM EST | C6.2 (6.24e-6 W/m²) |
| Nov 7, 6:30 AM EST | C1.2 (1.23e-6 W/m²) |
| Nov 7, 6:15 AM EST | B9.2 (9.24e-7 W/m²) |
| Nov 7, 6:00 AM EST | C1.0 (1.00e-6 W/m²) |
| Nov 7, 5:45 AM EST | C1.0 (1.04e-6 W/m²) |
| Nov 7, 5:30 AM EST | C1.6 (1.56e-6 W/m²) |
| Nov 7, 5:15 AM EST | C1.5 (1.54e-6 W/m²) |
| Nov 7, 5:00 AM EST | C1.5 (1.49e-6 W/m²) |
| Nov 7, 4:45 AM EST | C1.4 (1.35e-6 W/m²) |
| Nov 7, 4:30 AM EST | C1.5 (1.51e-6 W/m²) |
| Nov 7, 4:15 AM EST | C1.8 (1.81e-6 W/m²) |
| Nov 7, 4:00 AM EST | C1.5 (1.53e-6 W/m²) |
| Nov 7, 3:45 AM EST | C2.1 (2.08e-6 W/m²) |
| Nov 7, 3:30 AM EST | C2.7 (2.70e-6 W/m²) |
| Nov 7, 3:15 AM EST | C4.3 (4.26e-6 W/m²) |
| Nov 7, 3:00 AM EST | C2.5 (2.46e-6 W/m²) |
| Nov 7, 2:45 AM EST | C3.1 (3.11e-6 W/m²) |
| Nov 7, 2:30 AM EST | C5.5 (5.55e-6 W/m²) |
| Nov 7, 2:15 AM EST | C4.0 (3.97e-6 W/m²) |
| Nov 7, 2:00 AM EST | B7.5 (7.46e-7 W/m²) |
| Nov 7, 1:45 AM EST | B8.7 (8.70e-7 W/m²) |
| Nov 7, 1:30 AM EST | C1.4 (1.38e-6 W/m²) |
| Nov 7, 1:15 AM EST | C1.4 (1.43e-6 W/m²) |
| Nov 7, 1:00 AM EST | C1.2 (1.22e-6 W/m²) |
| Nov 7, 12:45 AM EST | C2.0 (1.95e-6 W/m²) |
| Nov 7, 12:30 AM EST | C1.3 (1.31e-6 W/m²) |
| Nov 7, 12:15 AM EST | C1.6 (1.57e-6 W/m²) |
| Nov 7, 12:00 AM EST | B9.5 (9.46e-7 W/m²) |
| Nov 6, 11:45 PM EST | C1.1 (1.08e-6 W/m²) |
| Nov 6, 11:30 PM EST | B8.2 (8.20e-7 W/m²) |
| Nov 6, 11:15 PM EST | B8.7 (8.73e-7 W/m²) |
| Nov 6, 11:00 PM EST | C1.8 (1.78e-6 W/m²) |
| Nov 6, 10:45 PM EST | C1.6 (1.64e-6 W/m²) |
| Nov 6, 10:30 PM EST | C5.0 (4.98e-6 W/m²) |
| Nov 6, 10:15 PM EST | C2.9 (2.92e-6 W/m²) |
| Nov 6, 10:00 PM EST | C1.3 (1.26e-6 W/m²) |
| Nov 6, 9:45 PM EST | C2.3 (2.27e-6 W/m²) |
| Nov 6, 9:30 PM EST | C2.4 (2.38e-6 W/m²) |
| Nov 6, 9:15 PM EST | C3.5 (3.53e-6 W/m²) |
| Nov 6, 9:00 PM EST | C3.1 (3.06e-6 W/m²) |
| Nov 6, 8:45 PM EST | C1.4 (1.44e-6 W/m²) |
| Nov 6, 8:30 PM EST | B8.3 (8.32e-7 W/m²) |
| Nov 6, 8:15 PM EST | C1.3 (1.29e-6 W/m²) |
| Nov 6, 8:00 PM EST | C3.1 (3.08e-6 W/m²) |
| Nov 6, 7:45 PM EST | C5.9 (5.92e-6 W/m²) |
| Nov 6, 7:30 PM EST | C1.2 (1.18e-6 W/m²) |
| Nov 6, 7:15 PM EST | C1.4 (1.42e-6 W/m²) |
| Nov 6, 7:00 PM EST | B8.0 (7.96e-7 W/m²) |
| Nov 6, 6:45 PM EST | C1.2 (1.18e-6 W/m²) |
| Nov 6, 6:30 PM EST | C4.1 (4.09e-6 W/m²) |
| Nov 6, 6:15 PM EST | C4.6 (4.61e-6 W/m²) |
| Nov 6, 6:00 PM EST | C4.2 (4.19e-6 W/m²) |
| Nov 6, 5:45 PM EST | C2.9 (2.91e-6 W/m²) |
| Nov 6, 5:30 PM EST | C3.5 (3.47e-6 W/m²) |
| Nov 6, 5:15 PM EST | C1.7 (1.65e-6 W/m²) |
| Nov 6, 5:00 PM EST | C1.7 (1.73e-6 W/m²) |
| Nov 6, 4:45 PM EST | C2.8 (2.76e-6 W/m²) |
| Nov 6, 4:30 PM EST | C2.9 (2.90e-6 W/m²) |
| Nov 6, 4:15 PM EST | C2.4 (2.41e-6 W/m²) |
| Nov 6, 4:00 PM EST | C2.6 (2.63e-6 W/m²) |
| Nov 6, 3:45 PM EST | C2.1 (2.09e-6 W/m²) |
| Nov 6, 3:30 PM EST | C1.4 (1.42e-6 W/m²) |
| Nov 6, 3:15 PM EST | C2.0 (2.04e-6 W/m²) |
| Nov 6, 3:00 PM EST | C2.2 (2.23e-6 W/m²) |
| Nov 6, 2:45 PM EST | B8.6 (8.57e-7 W/m²) |
| Nov 6, 2:30 PM EST | B8.8 (8.82e-7 W/m²) |
| Nov 6, 2:15 PM EST | B9.4 (9.45e-7 W/m²) |
| Nov 6, 2:00 PM EST | C1.0 (1.03e-6 W/m²) |
| Nov 6, 1:45 PM EST | C2.4 (2.42e-6 W/m²) |
| Nov 6, 1:30 PM EST | C2.9 (2.85e-6 W/m²) |
| Nov 6, 1:15 PM EST | C3.1 (3.10e-6 W/m²) |
| Nov 6, 1:00 PM EST | C1.0 (1.04e-6 W/m²) |
| Nov 6, 12:45 PM EST | C1.6 (1.59e-6 W/m²) |
| Nov 6, 12:30 PM EST | C1.5 (1.48e-6 W/m²) |
| Nov 6, 12:15 PM EST | B9.6 (9.56e-7 W/m²) |
| Nov 6, 12:00 PM EST | B9.4 (9.43e-7 W/m²) |
| Nov 6, 11:45 AM EST | C1.1 (1.07e-6 W/m²) |
| Nov 6, 11:30 AM EST | C1.1 (1.09e-6 W/m²) |
| Nov 6, 11:15 AM EST | B8.8 (8.81e-7 W/m²) |
| Nov 6, 11:00 AM EST | C2.3 (2.31e-6 W/m²) |
| Nov 6, 10:45 AM EST | C2.5 (2.53e-6 W/m²) |
| Nov 6, 10:30 AM EST | C1.4 (1.42e-6 W/m²) |
| Nov 6, 10:15 AM EST | C3.7 (3.73e-6 W/m²) |
| Nov 6, 10:00 AM EST | C1.0 (1.01e-6 W/m²) |
| Nov 6, 9:45 AM EST | C1.1 (1.05e-6 W/m²) |
| Nov 6, 9:30 AM EST | B8.6 (8.62e-7 W/m²) |
| Nov 6, 9:15 AM EST | C1.2 (1.17e-6 W/m²) |
| Nov 6, 9:00 AM EST | C1.8 (1.76e-6 W/m²) |
| Nov 6, 8:45 AM EST | C2.9 (2.94e-6 W/m²) |
| Nov 6, 8:30 AM EST | B9.9 (9.88e-7 W/m²) |
| Nov 6, 8:15 AM EST | C1.0 (1.04e-6 W/m²) |
| Nov 6, 8:00 AM EST | C1.1 (1.11e-6 W/m²) |
| Nov 6, 7:45 AM EST | C1.2 (1.24e-6 W/m²) |
| Nov 6, 7:30 AM EST | C1.3 (1.27e-6 W/m²) |
| Nov 6, 7:15 AM EST | C1.1 (1.08e-6 W/m²) |
| Nov 6, 7:00 AM EST | C1.2 (1.15e-6 W/m²) |
| Nov 6, 6:45 AM EST | B9.6 (9.61e-7 W/m²) |
| Nov 6, 6:30 AM EST | C1.0 (1.01e-6 W/m²) |
| Nov 6, 6:15 AM EST | B8.3 (8.31e-7 W/m²) |
| Nov 6, 6:00 AM EST | C2.2 (2.23e-6 W/m²) |
| Nov 6, 5:45 AM EST | B9.0 (9.04e-7 W/m²) |
| Nov 6, 5:30 AM EST | B9.7 (9.65e-7 W/m²) |
| Nov 6, 5:15 AM EST | C1.0 (1.04e-6 W/m²) |
| Nov 6, 5:00 AM EST | B8.8 (8.82e-7 W/m²) |
| Nov 6, 4:45 AM EST | B8.9 (8.90e-7 W/m²) |
| Nov 6, 4:30 AM EST | C1.0 (1.03e-6 W/m²) |
| Nov 6, 4:15 AM EST | C1.2 (1.18e-6 W/m²) |
| Nov 6, 4:00 AM EST | C1.2 (1.16e-6 W/m²) |
| Nov 6, 3:45 AM EST | C1.7 (1.65e-6 W/m²) |
| Nov 6, 3:30 AM EST | C2.6 (2.63e-6 W/m²) |
| Nov 6, 3:15 AM EST | C1.4 (1.41e-6 W/m²) |
| Nov 6, 3:00 AM EST | C4.0 (4.05e-6 W/m²) |
| Nov 6, 2:45 AM EST | C2.6 (2.55e-6 W/m²) |
| Nov 6, 2:30 AM EST | B7.7 (7.66e-7 W/m²) |
| Nov 6, 2:15 AM EST | C1.1 (1.13e-6 W/m²) |
| Nov 6, 2:00 AM EST | C1.4 (1.37e-6 W/m²) |
| Nov 6, 1:45 AM EST | B8.2 (8.19e-7 W/m²) |
| Nov 6, 1:30 AM EST | B9.0 (8.95e-7 W/m²) |
| Nov 6, 1:15 AM EST | B7.7 (7.70e-7 W/m²) |
| Nov 6, 1:00 AM EST | B7.9 (7.94e-7 W/m²) |
| Nov 6, 12:45 AM EST | B8.7 (8.72e-7 W/m²) |
| Nov 6, 12:30 AM EST | B9.4 (9.42e-7 W/m²) |
| Nov 6, 12:15 AM EST | C1.0 (1.04e-6 W/m²) |
| Nov 6, 12:00 AM EST | C1.5 (1.52e-6 W/m²) |
| Nov 5, 11:45 PM EST | C1.9 (1.89e-6 W/m²) |
| Nov 5, 11:30 PM EST | C1.5 (1.52e-6 W/m²) |
| Nov 5, 11:15 PM EST | C1.5 (1.55e-6 W/m²) |
| Nov 5, 11:00 PM EST | C1.6 (1.59e-6 W/m²) |
| Nov 5, 10:45 PM EST | C1.7 (1.73e-6 W/m²) |
| Nov 5, 10:30 PM EST | C2.0 (2.01e-6 W/m²) |
| Nov 5, 10:15 PM EST | C3.0 (3.04e-6 W/m²) |
| Nov 5, 10:00 PM EST | C4.5 (4.53e-6 W/m²) |
| Nov 5, 9:45 PM EST | C5.6 (5.63e-6 W/m²) |
| Nov 5, 9:30 PM EST | C3.0 (2.95e-6 W/m²) |
| Nov 5, 9:15 PM EST | B7.6 (7.61e-7 W/m²) |
| Nov 5, 9:00 PM EST | B8.4 (8.37e-7 W/m²) |
| Nov 5, 8:45 PM EST | B7.5 (7.48e-7 W/m²) |
| Nov 5, 8:30 PM EST | B7.8 (7.76e-7 W/m²) |
| Nov 5, 8:15 PM EST | B7.1 (7.06e-7 W/m²) |
| Nov 5, 8:00 PM EST | B7.2 (7.17e-7 W/m²) |
| Nov 5, 7:45 PM EST | B6.9 (6.94e-7 W/m²) |
| Nov 5, 7:30 PM EST | B8.3 (8.26e-7 W/m²) |
| Nov 5, 7:15 PM EST | C2.6 (2.56e-6 W/m²) |
| Nov 5, 7:00 PM EST | B6.1 (6.09e-7 W/m²) |
| Nov 5, 6:45 PM EST | B6.5 (6.48e-7 W/m²) |
| Nov 5, 6:30 PM EST | B6.7 (6.75e-7 W/m²) |
| Nov 5, 6:15 PM EST | B7.3 (7.26e-7 W/m²) |
| Nov 5, 6:00 PM EST | B8.3 (8.29e-7 W/m²) |
| Nov 5, 5:45 PM EST | B9.8 (9.78e-7 W/m²) |
| Nov 5, 5:30 PM EST | C1.3 (1.33e-6 W/m²) |
| Nov 5, 5:15 PM EST | C1.3 (1.28e-6 W/m²) |
| Nov 5, 5:00 PM EST | B8.4 (8.41e-7 W/m²) |
| Nov 5, 4:45 PM EST | B8.6 (8.61e-7 W/m²) |
| Nov 5, 4:30 PM EST | C3.0 (2.99e-6 W/m²) |
| Nov 5, 4:15 PM EST | C1.0 (1.00e-6 W/m²) |
| Nov 5, 4:00 PM EST | B9.8 (9.81e-7 W/m²) |
| Nov 5, 3:45 PM EST | C1.1 (1.12e-6 W/m²) |
| Nov 5, 3:30 PM EST | C1.1 (1.10e-6 W/m²) |
| Nov 5, 3:15 PM EST | C1.3 (1.31e-6 W/m²) |
| Nov 5, 3:00 PM EST | C1.2 (1.16e-6 W/m²) |
| Nov 5, 2:45 PM EST | B9.3 (9.29e-7 W/m²) |
| Nov 5, 2:30 PM EST | B8.9 (8.87e-7 W/m²) |
| Nov 5, 2:15 PM EST | C1.0 (1.00e-6 W/m²) |
| Nov 5, 2:00 PM EST | C2.0 (2.02e-6 W/m²) |
| Nov 5, 1:45 PM EST | M1.1 (1.07e-5 W/m²) |
| Nov 5, 1:30 PM EST | M3.6 (3.60e-5 W/m²) |
| Nov 5, 1:15 PM EST | C9.2 (9.19e-6 W/m²) |
| Nov 5, 1:00 PM EST | B10.0 (9.96e-7 W/m²) |
| Nov 5, 12:45 PM EST | C1.3 (1.30e-6 W/m²) |
| Nov 5, 12:30 PM EST | C1.1 (1.08e-6 W/m²) |
| Nov 5, 12:15 PM EST | C1.0 (1.05e-6 W/m²) |
| Nov 5, 12:00 PM EST | C1.1 (1.12e-6 W/m²) |
| Nov 5, 11:45 AM EST | C1.1 (1.09e-6 W/m²) |
| Nov 5, 11:30 AM EST | B8.0 (8.04e-7 W/m²) |
| Nov 5, 11:15 AM EST | B8.1 (8.05e-7 W/m²) |
| Nov 5, 11:00 AM EST | B8.3 (8.28e-7 W/m²) |
| Nov 5, 10:45 AM EST | B8.1 (8.12e-7 W/m²) |
| Nov 5, 10:30 AM EST | B8.4 (8.36e-7 W/m²) |
| Nov 5, 10:15 AM EST | B8.8 (8.76e-7 W/m²) |
| Nov 5, 10:00 AM EST | B8.7 (8.73e-7 W/m²) |
| Nov 5, 9:45 AM EST | B9.4 (9.39e-7 W/m²) |
| Nov 5, 9:30 AM EST | B9.6 (9.59e-7 W/m²) |
| Nov 5, 9:15 AM EST | B8.5 (8.51e-7 W/m²) |
| Nov 5, 9:00 AM EST | B7.8 (7.84e-7 W/m²) |
| Nov 5, 8:45 AM EST | C1.1 (1.07e-6 W/m²) |
| Nov 5, 8:30 AM EST | C1.1 (1.11e-6 W/m²) |
| Nov 5, 8:15 AM EST | B7.8 (7.78e-7 W/m²) |
| Nov 5, 8:00 AM EST | B6.9 (6.86e-7 W/m²) |
| Nov 5, 7:45 AM EST | B7.1 (7.15e-7 W/m²) |
| Nov 5, 7:30 AM EST | B7.4 (7.41e-7 W/m²) |
| Nov 5, 7:15 AM EST | B7.7 (7.74e-7 W/m²) |
| Nov 5, 7:00 AM EST | B7.8 (7.81e-7 W/m²) |
| Nov 5, 6:45 AM EST | B8.0 (8.02e-7 W/m²) |
| Nov 5, 6:30 AM EST | B8.8 (8.77e-7 W/m²) |
| Nov 5, 6:15 AM EST | B9.3 (9.30e-7 W/m²) |
| Nov 5, 6:00 AM EST | B7.6 (7.56e-7 W/m²) |
| Nov 5, 5:45 AM EST | B6.8 (6.81e-7 W/m²) |
| Nov 5, 5:30 AM EST | B6.7 (6.71e-7 W/m²) |
| Nov 5, 5:15 AM EST | B7.0 (7.03e-7 W/m²) |
| Nov 5, 5:00 AM EST | B7.0 (6.97e-7 W/m²) |
| Nov 5, 4:45 AM EST | B6.1 (6.15e-7 W/m²) |
| Nov 5, 4:30 AM EST | B6.1 (6.08e-7 W/m²) |
| Nov 5, 4:15 AM EST | B6.5 (6.45e-7 W/m²) |
| Nov 5, 4:00 AM EST | B6.8 (6.76e-7 W/m²) |
| Nov 5, 3:45 AM EST | B6.1 (6.11e-7 W/m²) |
| Nov 5, 3:30 AM EST | B6.8 (6.81e-7 W/m²) |
| Nov 5, 3:15 AM EST | B6.9 (6.85e-7 W/m²) |
| Nov 5, 3:00 AM EST | B7.9 (7.95e-7 W/m²) |
| Nov 5, 2:45 AM EST | B8.6 (8.59e-7 W/m²) |
| Nov 5, 2:30 AM EST | B6.9 (6.94e-7 W/m²) |
| Nov 5, 2:15 AM EST | B7.1 (7.15e-7 W/m²) |
| Nov 5, 2:00 AM EST | B8.2 (8.18e-7 W/m²) |
| Nov 5, 1:45 AM EST | C1.2 (1.17e-6 W/m²) |
| Nov 5, 1:30 AM EST | B9.2 (9.23e-7 W/m²) |
| Nov 5, 1:15 AM EST | B7.5 (7.52e-7 W/m²) |
| Nov 5, 1:00 AM EST | B9.1 (9.15e-7 W/m²) |
| Nov 5, 12:45 AM EST | B6.9 (6.92e-7 W/m²) |
| Nov 5, 12:30 AM EST | B6.5 (6.48e-7 W/m²) |
| Nov 5, 12:15 AM EST | B9.7 (9.70e-7 W/m²) |
| Nov 5, 12:00 AM EST | B6.3 (6.32e-7 W/m²) |
| Nov 4, 11:45 PM EST | B5.1 (5.13e-7 W/m²) |
| Nov 4, 11:30 PM EST | B5.2 (5.19e-7 W/m²) |
| Nov 4, 11:15 PM EST | B5.4 (5.35e-7 W/m²) |
| Nov 4, 11:00 PM EST | B5.5 (5.46e-7 W/m²) |
| Nov 4, 10:45 PM EST | B5.2 (5.17e-7 W/m²) |
| Nov 4, 10:30 PM EST | B5.3 (5.32e-7 W/m²) |
| Nov 4, 10:15 PM EST | B5.1 (5.12e-7 W/m²) |
| Nov 4, 10:00 PM EST | B5.3 (5.29e-7 W/m²) |
| Nov 4, 9:45 PM EST | B5.3 (5.32e-7 W/m²) |
| Nov 4, 9:30 PM EST | B5.1 (5.06e-7 W/m²) |
| Nov 4, 9:15 PM EST | B9.1 (9.10e-7 W/m²) |
| Nov 4, 9:00 PM EST | B5.7 (5.71e-7 W/m²) |
| Nov 4, 8:45 PM EST | B5.2 (5.19e-7 W/m²) |
| Nov 4, 8:30 PM EST | B6.0 (5.97e-7 W/m²) |
| Nov 4, 8:15 PM EST | B6.7 (6.67e-7 W/m²) |
| Nov 4, 8:00 PM EST | B4.8 (4.83e-7 W/m²) |
| Nov 4, 7:45 PM EST | B5.2 (5.17e-7 W/m²) |
| Nov 4, 7:30 PM EST | B5.2 (5.22e-7 W/m²) |
| Nov 4, 7:15 PM EST | B6.6 (6.59e-7 W/m²) |
| Nov 4, 7:00 PM EST | B9.4 (9.42e-7 W/m²) |
| Nov 4, 6:45 PM EST | B5.1 (5.11e-7 W/m²) |
| Nov 4, 6:30 PM EST | B6.4 (6.37e-7 W/m²) |
| Nov 4, 6:15 PM EST | B7.7 (7.70e-7 W/m²) |
| Nov 4, 6:00 PM EST | C1.3 (1.31e-6 W/m²) |
| Nov 4, 4:15 PM EST | B6.2 (6.19e-7 W/m²) |
| Nov 4, 4:00 PM EST | B7.3 (7.29e-7 W/m²) |
| Nov 4, 3:45 PM EST | B8.2 (8.22e-7 W/m²) |
| Nov 4, 3:30 PM EST | B5.8 (5.82e-7 W/m²) |
| Nov 4, 3:15 PM EST | B5.8 (5.77e-7 W/m²) |
| Nov 4, 3:00 PM EST | B5.6 (5.65e-7 W/m²) |
| Nov 4, 2:45 PM EST | B5.9 (5.92e-7 W/m²) |
| Nov 4, 2:30 PM EST | B5.9 (5.93e-7 W/m²) |
| Nov 4, 2:15 PM EST | B6.4 (6.42e-7 W/m²) |
| Nov 4, 2:00 PM EST | B6.9 (6.93e-7 W/m²) |
| Nov 4, 1:45 PM EST | B6.5 (6.48e-7 W/m²) |
| Nov 4, 1:30 PM EST | B6.8 (6.83e-7 W/m²) |
| Nov 4, 1:15 PM EST | B6.9 (6.89e-7 W/m²) |
| Nov 4, 1:00 PM EST | B7.3 (7.28e-7 W/m²) |
| Nov 4, 12:45 PM EST | B9.8 (9.85e-7 W/m²) |
Readings: NOAA GOES X-ray product. Times are shown in Eastern time. The graph keeps the highest X-ray reading in each 15-minute period. Missing measurements are left blank, not treated as zero.
Why does it matter for HF?
Strong flares can increase absorption of HF signals on Earth's sunlit side and cause radio blackouts. The effect depends on flare strength, duration, and whether your path is in daylight.
How should I use the graph?
Look for a sharp rise and the time it occurred. This graph uses a logarithmic scale so small and large flares fit together; compare it with NOAA's R scale for radio-blackout severity.
Learn more from NOAA Space Weather Prediction Center and ARRL's HF propagation guide.