Solar Watch — August 21, 2026 | 18:00 UTC

☀ Helios Solar Watch · 2026-08-21 16:00 UTC
QUIET

Solar activity remains in an unsettled state characterized by frequent M-class flaring despite low current geomagnetic indices. Seven active regions are currently identified on the solar disk, with AR4513 showing notable complexity.

⚡ Flare activity — last 12 h
Peak: M @ 10:18 UTC (5h 42min ago) · M @ 09:35 UTC · M @ 10:06 UTC · M @ 10:37 UTC · M @ 11:08 UTC
HMI Continuum Intensity

Visible light · 4 active regions

SUVI 304 — Extreme UV

Extreme UV · 304 Å

Kp Index
2.0
5 or above = storm

Geomagnetic
G0
24 h max: G0

X-Ray
A/B
quiet


⚠ Electron flux F3 reached · 4 more below
Next 24 h

Geomagnetic activity is expected to remain largely quiet, with a brief uptick to Kp 3.67 anticipated late on August 21st. Flare probability remains elevated for the next 24 hours, with a 55% chance of further M-class activity.

🌌 Aurora

Aurora visibility is not expected for mid-latitudes at this time.

more

Observers at very high latitudes may see minor activity if the forecast Kp 3 peak materializes, but no significant displays are anticipated.

👁 Watch for

Monitor the evolution of active region AR4513 as it rotates across the solar disk, as its current classification suggests potential for further eruptive activity.

▸ Detailed readings

Radio blackout
 R0
(24 h max R0)
Radiation
 S0
(24 h max S0)
F10.7
 111.0
sfu

Region Location Class Flares C/M/X
AR4513 N04E55 Eac/BGD 4/0/0
AR4514 S10W70 Cro/B 1/0/0
AR4515 S08E63 Hrx/A 0/0/0
AR4508 N09W64 Hrx/A 0/0/0
NOAA messages
2026-08-21 11:18  Electron flux F3 reached (ALTEF3)
2026-08-21 09:45  SUM10R (SUM10R)
2026-08-20 20:49  ALTTP2 (ALTTP2)
2026-08-20 12:12  X-ray flare M5 summary (SUMXM5)
2026-08-20 11:39  X-ray flare MF reached (ALTXMF)


Helios Observer · Data: NOAA SWPC · updated every 12 h