AAVSO Sudden Ionospheric Disturbance Report May 2026 Observers: A118 A119 A136 A138 A148 A150 A153 A96 YYMMDD Event Peak Importance 260501 1530 1+ 260502 1404 2 260502 1523 1- 260502 1535 1+ 260502 1839 1+ 260502 2024 2 A150 - XRA 260503 0709 1+ 260503 1410 2+ A150 - QUAL 260503 1527 2 A150 - QUAL 260503 1714 2+ A150 - QUAL 260504 0133 2+ A153 - XRA 260507 1437 3+ 260507 1444 3+ A150 - QUAL 260507 1451 2+ A96 - QUAL 260507 1500 3+ A138 - XRA 260507 1517 3+ 260507 1547 3+ A148 - QUAL 260507 1755 1+ 260508 1551 1+ 260508 1907 1- A148 - XRA 260508 2020 1+ 260509 2016 1- A148 - XRA 260510 0925 1- 260510 0940 1- 260510 1334 2+ 260510 1341 2+ 260510 1519 3+ A138 - FLA 260510 1752 1+ A118 - QUAL 260513 1716 2 260513 1806 1 A153 - XRA 260513 1947 1 260514 0643 1+ 260514 0922 1- A118 - XRA 260514 1059 2 A136 - XRA 260514 1135 1+ 260514 1431 1- A148 - XRA 260514 1726 2+ 260515 1151 1+ 260515 1314 1 260515 1615 1+ 260515 2253 1- A148 - XRA 260516 1513 1- 260516 1610 2 260516 1626 1+ 260516 1742 1+ 260516 1908 1- A148 - XRA 260516 2005 1 260516 2331 1+ A148 - XRA 260517 2055 2 260517 2140 3+ A138 - QUAL 260521 1321 1 260521 1815 1+ 260522 1012 2+ 260522 1026 3 260523 1146 1- A148 - XRA 260523 1918 2+ 260523 2204 1- 260524 1751 2+ A150 - QUAL 260526 0838 1+ A136 - XRA 260526 1239 2 260526 1356 1 A118 - XRA 260526 2018 1+ 260526 2350 1- A148 - XRA 260528 1516 1 A148 - XRA 260529 0536 2 260529 0700 2+ 260529 1942 1+ 260529 1946 2 260529 2131 1 A148 - XRA 260530 0746 1+ 260530 1154 1 260530 1154 1 260531 1807 1 A148 - XRA 260531 1807 1 A148 - XRA ************************************************** Importance Summary - May 2026 1- events: 13 1 events: 12 1+ events: 20 2 events: 10 2+ events: 11 3 events: 1 3+ events: 7 ------------------ Total events: 74