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.
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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) |
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.