Solar flare
Other large solar flares also occurred on April 2, 2001 (X20), October 28, 2003 (X17.2 and 10), September 7, 2005 (X17), February 17, 2011 (X2), August 9, 2011 (X6.9), March 7, 2012 (X5.4), July 6, 2012 (X1.1). On July 6, 2012, a solar storm hit just after midnight UK time, when an X1.1 solar flare fired out of the AR1515 sunspot. Another X1.4 solar flare from AR 1520 region of the Sun, second in the week, reached the Earth on July 15, 2012 with a geomagnetic storm of G1–G2 level. A X1.8-class flare was recorded on October 24, 2012. There has been major solar flare activity in early 2013, notably within a 48-hour period starting on May 12, 2013, a total of four X-class solar flares were emitted ranging from an X1.2 and upwards of an X3.2, the latter of which was one of the largest year 2013 flares. Departing sunspot complex AR2035-AR2046 erupted on April 25, 2014 at 0032 UT, producing a strong X1.3-class solar flare and an HF communications blackout on the day-side of Earth. NASA's Solar Dynamics Observatory recorded a flash of extreme ultraviolet radiation from the explosion. The Solar Dynamics Observatory recorded an X9.3-class flare at around 1200 UTC on September 6, 2017.
Solar cycle 24
A filament eruption occurred in late hours of September 27 resulted in a brief S1 (minor) radiation storm, alerted by NOAA in early hours of next day. The Earth-directed CME associated with this event affected our planet on September 30. Geomagnetic storm levels reached the G3 on October 1. The filament eruption was connected to a C3.7 flare occurred in the vicinity of sunspot 1577.
Solar activity decreased remarkably this month. 4 minor solar flares, below M2 levels, were registered in September 2012.
On October 8 and 9, the arrival of a CME unrelated to solar flares and emitted on October 5 caused disturbances in the horizontal component of the Earth's magnetic field. The planetary Kp-index reached level 6, so a G2 (moderate) geomagnetic storm was reported. 
The Sun released a M9.0 flare on October 20. This was followed three days after on October 23, by a very impulsive flare, peaking as an X1.8 class event at 3:17 a.m. UTC. 
Both flares came from active region 1598 located on the left side (east) of the sun, which had previously been the source of a number of weaker flares. The M9.0 burst occurred when the sunspot was not yet rotated onto the Earth-facing side of the solar disk. The NOAA categorized the radio blackout associated with the X1.8 event as an R3, on a scale from R1 to R5. This was the 7th and last X-class flare in 2012. There was no associated Earth-directed coronal mass ejection (CME).