How often do solar flares occur?
Solar flare
The frequency of occurrence of solar flares varies, from several per day when the Sun is particularly "active" to less than one every week when the Sun is "quiet", following the 11-year cycle (the solar cycle). Large flares are less frequent than smaller ones.
Solar cycle 24
On August 31, 2012 a long filament of solar material that had been hovering in the Sun's atmosphere (the corona), erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 1500 km (900 miles) per second. The CME did not travel directly toward Earth, but did connect with Earth's magnetic environment, or magnetosphere, with a glancing blow. causing aurorae to appear on the night of Monday, September 3. A G2 (moderate) geomagnetic storm was registered on September 3 and September 5.
The Sun erupted 10 M-class flares this month, the largest being a M5.5 burst ejected on August 18.