TABLE 4 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 24 CYCLE 25 AND BEGINNING OF CYCLE 26 TIME SUNSPOT NUMBERS GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2009.3337 MAY 3.7 2.6 1.4 4.9 4.6 4.4 2009.4170 JUN 5.2 2.9 0.7 5.5 4.8 4.2 2009.5003 JUL 7.0 3.4 0.3 5.8 4.8 4.0 2009.5837 AUG 8.7 4.1 0.0 6.2 4.7 3.8 2009.6670 SEP 11.5 4.8 0.0 6.5 4.7 3.4 2009.7503 OCT 14.1 5.4 0.0 6.5 4.7 3.4 2009.8337 NOV 17.0 6.1 0.0 6.4 4.6 3.1 2009.9170 DEC 20.1 6.9 0.0 6.3 4.3 2.9 2010.0003 JAN 22.1 7.9 0.0 5.8 3.6 1.9 2010.0837 FEB 25.2 8.7 0.0 5.6 3.2 1.2 2010.1670 MAR 29.6 10.0 0.0 5.7 2.9 0.9 2010.2503 APR 34.8 11.6 0.0 6.0 2.7 0.2 2010.3337 MAY 40.6 13.1 0.0 7.1 2.9 0.0 2010.4170 JUN 46.4 14.5 0.0 8.0 3.2 0.1 2010.5003 JUL 50.9 16.6 0.0 7.9 3.1 -0.1 2010.5837 AUG 56.3 19.0 0.0 7.6 2.9 -0.4 2010.6670 SEP 62.2 21.5 0.0 6.5 2.3 -0.9 2010.7503 OCT 68.1 23.9 0.0 5.5 1.9 -1.0 2010.8337 NOV 75.1 26.0 0.0 4.9 1.8 -0.8 2010.9170 DEC 82.9 28.0 0.0 4.4 1.9 -0.7 2011.0003 JAN 89.8 30.3 0.0 5.0 2.2 -0.3 2011.0837 FEB 95.6 32.3 0.0 6.7 3.2 1.0 2011.1670 MAR 101.8 34.3 0.0 7.6 4.2 1.8 2011.2503 APR 108.1 36.8 0.0 7.5 4.5 1.9 2011.3337 MAY 111.8 38.6 0.0 7.8 4.9 1.9 2011.4170 JUN 113.5 40.3 0.0 8.5 5.1 1.5 2011.5003 JUL 116.3 42.3 0.0 9.2 5.3 1.1 2011.5837 AUG 118.8 43.8 0.0 9.6 5.8 1.4 2011.6670 SEP 122.2 45.5 0.0 10.4 6.5 1.9 2011.7503 OCT 127.8 47.4 0.0 11.6 7.2 2.6 2011.8337 NOV 132.0 49.4 0.0 12.6 7.8 2.7 2011.9170 DEC 134.4 51.6 0.0 13.1 8.1 2.6 2012.0003 JAN 139.1 54.1 1.5 13.2 8.6 2.5 2012.0837 FEB 144.4 56.3 2.5 13.0 9.0 2.6 2012.1670 MAR 147.6 58.0 3.6 13.3 9.2 2.7 2012.2503 APR 150.0 59.6 3.9 13.6 9.0 2.5 2012.3337 MAY 152.9 61.0 4.1 14.1 8.8 2.0 2012.4170 JUN 155.5 62.5 4.6 14.8 9.3 2.5 2012.5003 JUL 157.7 64.1 5.1 15.4 10.3 4.0 2012.5837 AUG 160.5 65.9 7.2 15.9 11.0 5.3 2012.6670 SEP 162.8 67.6 8.9 15.8 11.2 5.9 2012.7503 OCT 161.9 67.9 9.6 15.2 10.9 6.0 2012.8337 NOV 160.9 68.4 10.9 15.2 10.9 6.2 2012.9170 DEC 162.4 69.3 12.6 14.8 10.8 6.1 2013.0003 JAN 163.2 69.4 14.4 13.5 10.2 5.4 2013.0837 FEB 161.0 69.6 16.7 12.6 9.9 5.3 2013.1670 MAR 158.6 70.9 20.0 11.8 8.8 4.6 2013.2503 APR 156.0 72.4 23.6 11.2 7.8 3.7 2013.3337 MAY 154.3 73.0 26.3 11.2 7.5 3.3 2013.4170 JUN 153.7 72.9 27.7 11.5 7.0 2.5 2013.5003 JUL 153.1 73.1 28.7 11.9 6.4 1.8 2013.5837 AUG 152.8 73.7 30.4 12.0 6.2 1.7 2013.6670 SEP 152.4 73.9 32.6 12.4 5.9 1.3 2013.7503 OCT 152.8 73.8 30.3 12.3 5.7 1.0 2013.8337 NOV 153.4 73.3 28.7 12.3 6.2 1.7 2013.9170 DEC 153.3 73.3 28.2 12.7 6.6 2.2 2014.0003 JAN 152.4 73.3 28.8 12.2 6.8 3.7 2014.0837 FEB 149.4 72.3 28.1 11.0 7.0 4.1 2014.1670 MAR 144.6 69.8 25.6 11.1 7.2 4.5 2014.2503 APR 140.7 67.6 22.9 11.6 7.7 4.8 2014.3337 MAY 136.9 66.0 20.7 12.0 8.0 5.1 2014.4170 JUN 132.1 64.3 18.5 13.1 8.7 5.5 2014.5003 JUL 128.4 62.4 17.2 13.8 9.1 5.9 2014.5837 AUG 124.9 60.5 16.3 12.7 8.5 5.5 2014.6670 SEP 121.7 59.7 16.7 11.9 8.1 5.0 2014.7503 OCT 119.4 59.8 18.0 11.9 8.3 4.9 2014.8337 NOV 116.2 59.5 19.1 11.6 8.1 4.7 2014.9170 DEC 112.8 58.2 19.7 11.8 7.9 4.2 2015.0003 JAN 110.5 57.2 20.8 12.1 7.8 3.8 2015.0837 FEB 108.2 56.8 21.3 13.2 8.2 3.8 2015.1670 MAR 106.4 56.1 20.0 15.0 9.4 4.7 2015.2503 APR 104.1 55.2 18.6 16.1 10.2 5.5 2015.3337 MAY 101.7 54.2 18.0 17.1 10.9 6.6 2015.4170 JUN 98.0 53.1 17.2 17.7 11.6 6.6 2015.5003 JUL 93.3 52.1 16.4 17.7 12.1 7.3 2015.5837 AUG 89.7 51.4 16.2 17.6 12.7 8.3 2015.6670 SEP 86.0 50.3 16.3 17.3 13.2 9.2 2015.7503 OCT 81.2 48.5 16.0 18.3 13.5 9.9 2015.8337 NOV 76.4 46.3 15.6 19.1 14.1 10.7 2015.9170 DEC 72.6 43.8 14.3 19.8 14.9 11.1 2016.0003 JAN 69.7 41.5 13.1 20.6 15.3 11.2 2016.0837 FEB 67.1 40.0 13.0 20.4 15.1 10.6 2016.1670 MAR 65.1 38.6 11.2 20.4 14.8 10.3 2016.2503 APR 63.4 37.7 8.7 20.7 14.4 10.0 2016.3337 MAY 64.4 37.0 7.0 20.7 13.9 9.4 2016.4170 JUN 65.0 36.5 6.4 21.1 13.6 8.4 2016.5003 JUL 64.2 35.3 5.6 21.4 13.0 7.2 2016.5837 AUG 64.2 34.3 5.1 21.3 12.2 6.3 2016.6670 SEP 63.4 33.3 4.2 21.4 11.9 5.9 2016.7503 OCT 60.7 31.8 3.2 21.6 11.9 5.7 2016.8337 NOV 58.8 30.8 2.8 21.2 11.5 5.5 2016.9170 DEC 58.6 30.2 2.4 20.2 11.1 5.2 2017.0003 JAN 58.0 29.8 2.3 19.3 10.9 5.3 2017.0837 FEB 57.5 29.5 2.5 18.7 11.1 5.9 2017.1670 MAR 55.7 29.0 2.9 19.0 11.9 6.8 2017.2503 APR 53.0 28.3 3.6 18.9 12.3 7.1 2017.3337 MAY 49.2 27.1 4.1 19.1 12.9 7.9 2017.4170 JUN 46.5 25.8 3.7 19.2 13.4 8.8 2017.5003 JUL 46.9 25.3 3.9 19.2 13.9 9.6 2017.5837 AUG 46.3 24.7 4.3 19.1 14.0 10.1 2017.6670 SEP 43.2 23.2 4.4 19.5 14.1 10.5 2017.7503 OCT 40.3 21.6 3.9 19.8 14.1 10.4 2017.8337 NOV 39.1 20.7 3.5 19.8 14.3 10.1 2017.9170 DEC 38.3 19.7 3.5 19.9 14.8 10.1 2018.0003 JAN 36.5 18.4 3.2 20.1 15.7 10.4 2018.0837 FEB 33.6 17.2 2.7 20.0 16.5 10.6 2018.1670 MAR 30.7 16.0 1.8 20.3 16.8 10.2 2018.2503 APR 29.4 15.3 1.7 20.1 16.6 9.8 2018.3337 MAY 28.1 14.6 1.6 19.7 16.3 9.7 2018.4170 JUN 26.8 13.9 1.4 19.0 15.9 9.7 2018.5003 JUL 25.5 13.2 1.3 19.2 16.1 10.3 2018.5837 AUG 24.3 12.5 1.2 19.8 16.7 11.2 2018.6670 SEP 23.0 11.9 1.1 20.4 17.0 11.5 2018.7503 OCT 21.9 11.2 1.0 20.5 17.0 11.7 2018.8337 NOV 20.7 10.6 0.8 20.2 16.7 11.6 2018.9170 DEC 19.6 10.0 0.7 19.1 15.8 11.1 2019.0003 JAN 18.6 9.4 0.6 18.1 15.0 10.5 2019.0837 FEB 17.6 8.9 0.5 17.1 14.1 10.0 2019.1670 MAR 16.6 8.4 0.4 16.1 13.3 9.5 2019.2503 APR 15.8 8.0 0.4 15.2 12.5 9.1 2019.3337 MAY 15.0 7.5 0.3 14.3 11.7 8.6 2019.4170 JUN 14.3 7.2 0.2 13.5 11.1 8.2 2019.5003 JUL 13.7 6.8 0.2 12.8 10.5 7.9 2019.5837 AUG 13.2 6.6 0.1 12.2 9.9 7.5 2019.6670 SEP 12.8 6.4 0.1 11.7 9.5 7.3 2019.7503 OCT 12.5 6.2 0.0 11.4 9.2 7.1 2019.8337 NOV 12.3 6.1 0.0 11.1 9.0 7.0 2019.9170 DEC 12.3 6.1 0.0 11.1 9.0 6.9 2020.0003 JAN 12.9 6.5 0.4 11.3 9.0 6.9 2020.0837 FEB 14.2 7.2 0.9 11.6 9.2 7.1 2020.1670 MAR 15.4 7.8 1.2 11.7 9.3 7.4 2020.2503 APR 16.6 8.5 1.7 11.9 9.4 7.5 2020.3337 MAY 18.1 9.3 1.8 12.0 9.5 7.5 2020.4170 JUN 20.6 10.2 2.3 12.1 9.6 7.3 2020.5003 JUL 23.0 11.2 2.9 12.2 9.7 7.2 2020.5837 AUG 25.1 12.3 3.1 12.5 9.9 7.1 2020.6670 SEP 28.3 13.6 3.2 12.8 10.1 7.0 2020.7503 OCT 32.2 15.1 3.5 13.2 10.5 7.2 2020.8337 NOV 38.2 16.9 3.5 13.7 10.8 7.6 2020.9170 DEC 43.7 19.0 3.5 14.5 11.1 7.9 2021.0003 JAN 47.9 21.0 4.2 15.7 11.4 7.7 2021.0837 FEB 54.1 23.4 4.3 16.1 11.6 7.7 2021.1670 MAR 60.7 25.9 4.3 16.3 11.8 7.6 2021.2503 APR 66.8 28.4 4.8 16.8 12.0 7.6 2021.3337 MAY 74.4 31.2 4.8 18.0 12.3 7.6 2021.4170 JUN 83.1 34.5 5.2 18.9 12.6 7.7 2021.5003 JUL 89.9 37.8 5.8 19.1 12.7 7.7 2021.5837 AUG 95.1 41.3 6.8 19.2 12.9 7.8 2021.6670 SEP 100.0 44.8 7.7 19.0 13.1 7.7 2021.7503 OCT 105.0 48.2 9.1 18.6 13.1 7.7 2021.8337 NOV 110.5 51.5 9.8 18.5 13.2 7.8 2021.9170 DEC 116.5 54.9 9.9 18.9 13.4 8.0 2022.0003 JAN 122.0 58.5 11.2 18.8 13.5 8.2 2022.0837 FEB 126.8 62.1 12.4 17.8 13.5 8.6 2022.1670 MAR 134.1 65.8 13.4 17.9 13.7 8.7 2022.2503 APR 141.4 69.4 14.6 18.5 13.9 8.7 2022.3337 MAY 146.1 72.7 15.1 19.1 14.2 9.0 2022.4170 JUN 147.9 75.6 15.6 19.6 14.6 9.4 2022.5003 JUL 151.0 78.5 16.2 20.3 14.9 9.6 2022.5837 AUG 154.7 80.9 16.7 20.3 15.1 9.6 2022.6670 SEP 158.4 83.0 17.1 20.3 15.1 9.8 2022.7503 OCT 163.8 85.3 17.1 20.5 15.2 10.0 2022.8337 NOV 167.3 87.7 16.7 20.8 15.4 10.5 2022.9170 DEC 169.1 90.1 16.4 21.2 15.4 11.1 2023.0003 JAN 172.9 92.3 16.8 21.3 15.3 11.6 2023.0837 FEB 177.6 94.2 17.5 21.4 15.1 11.3 2023.1670 MAR 180.4 96.2 18.7 21.6 15.0 11.2 2023.2503 APR 182.4 98.4 20.6 22.0 15.0 10.7 2023.3337 MAY 185.0 100.2 21.8 22.8 14.9 10.2 2023.4170 JUN 187.4 101.3 23.1 22.5 14.7 9.9 2023.5003 JUL 189.5 102.2 25.4 21.3 14.5 10.1 2023.5837 AUG 190.7 102.4 28.1 20.6 14.3 10.1 2023.6670 SEP 192.2 102.8 30.7 20.1 14.2 10.3 2023.7503 OCT 192.5 103.6 32.1 19.6 14.1 10.6 2023.8337 NOV 192.1 104.1 33.4 19.5 14.0 10.6 2023.9170 DEC 193.4 104.4 35.7 19.3 14.0 10.5 2024.0003 JAN 193.9 103.6 37.4 19.1 14.2 10.5 2024.0837 FEB 190.8 102.1 39.6 18.9 14.6 10.5 2024.1670 MAR 186.3 101.2 41.2 18.9 14.7 10.3 2024.2503 APR 181.9 100.7 42.7 19.5 14.6 9.8 2024.3337 MAY 179.6 100.4 43.9 20.4 14.7 10.2 2024.4170 JUN 178.9 100.1 43.8 22.0 15.0 10.7 2024.5003 JUL 177.8 99.7 43.3 23.4 15.3 10.7 2024.5837 AUG 176.5 99.1 44.0 24.0 15.4 10.9 2024.6670 SEP 175.3 98.5 45.9 25.1 15.7 11.1 2024.7503 OCT 174.5 98.0 46.0 25.6 15.9 11.3 2024.8337 NOV 173.4 97.4 45.1 24.9 15.9 11.5 2024.9170 DEC 172.3 96.6 44.4 24.8 15.9 11.7 2025.0003 JAN 170.7 95.7 44.9 23.9 15.8 11.9 2025.0837 FEB 168.1 94.1 45.4 22.1 15.8 11.8 2025.1670 MAR 164.2 92.1 44.3 22.4 15.9 12.0 2025.2503 APR 161.0 90.3 43.7 23.1 16.0 11.8 2025.3337 MAY 157.9 89.1 44.7 23.1 16.0 11.1 2025.4170 JUN 153.9 87.8 45.7 22.6 16.0 10.8 2025.5003 JUL 150.5 86.2 44.6 22.0 15.8 10.8 2025.5837 AUG 146.4 84.3 42.6 21.9 15.8 10.8 2025.6670 SEP 142.9 82.9 41.6 22.7 16.1 10.8 2025.7503 OCT 142.0 81.8 41.3 23.7 16.5 10.8 2025.8337 NOV 138.7 80.3 39.3 23.9 16.7 10.8 2025.9170 DEC 136.4 78.4 35.0 23.9 17.0 10.7 2026.0003 JAN 135.3 76.6 34.1 23.9 17.1 10.6 2026.0837 FEB 132.3 74.9 35.4 23.5 17.2 10.3 2026.1670 MAR 128.8 73.5 34.6 22.5 17.2 10.5 2026.2503 APR 124.8 72.3 32.7 22.7 17.2 10.7 2026.3337 MAY 120.7 71.1 31.7 23.0 17.4 11.4 2026.4170 JUN 117.2 69.7 30.9 23.1 17.6 11.9 2026.5003 JUL 114.8 68.0 29.4 22.5 17.8 12.0 2026.5837 AUG 110.8 66.0 27.7 21.7 17.6 12.1 2026.6670 SEP 104.4 63.7 26.7 21.2 17.4 12.3 2026.7503 OCT 97.6 61.3 26.3 21.7 17.0 12.5 2026.8337 NOV 93.7 59.4 26.6 21.7 16.9 13.3 2026.9170 DEC 92.5 57.7 25.8 22.1 16.9 13.1 2027.0003 JAN 91.4 56.1 24.3 22.6 17.0 12.8 2027.0837 FEB 88.9 54.7 24.4 22.3 16.8 13.1 2027.1670 MAR 86.8 53.1 23.8 22.4 16.5 12.7 2027.2503 APR 83.1 51.4 22.7 22.7 16.2 12.5 2027.3337 MAY 79.8 49.8 21.9 22.9 15.8 12.1 2027.4170 JUN 76.3 48.2 20.4 23.5 15.6 11.2 2027.5003 JUL 71.0 46.4 18.9 24.1 15.4 10.5 2027.5837 AUG 69.8 44.7 16.7 24.8 15.3 10.7 2027.6670 SEP 70.1 43.5 14.9 25.3 15.3 10.8 2027.7503 OCT 69.7 42.3 13.7 25.6 15.3 10.6 2027.8337 NOV 69.6 41.1 11.9 25.4 15.3 10.8 2027.9170 DEC 68.8 39.7 10.4 24.9 15.2 11.0 2028.0003 JAN 66.8 38.2 9.5 24.0 15.0 11.1 2028.0837 FEB 64.1 36.8 8.7 23.0 14.9 11.3 2028.1670 MAR 60.9 35.5 7.9 22.5 15.0 11.2 2028.2503 APR 56.4 34.1 7.8 22.1 15.1 11.1 2028.3337 MAY 52.1 32.5 7.9 21.8 15.2 11.2 2028.4170 JUN 49.0 31.3 7.6 21.4 15.3 11.4 2028.5003 JUL 49.8 30.5 7.5 20.7 15.2 11.5 2028.5837 AUG 49.0 29.5 7.4 19.9 14.9 11.3 2028.6670 SEP 46.4 28.2 7.1 20.0 14.7 11.1 2028.7503 OCT 44.0 26.8 6.5 20.1 14.6 10.8 2028.8337 NOV 42.0 25.7 6.5 19.9 14.3 10.1 2028.9170 DEC 40.9 24.9 6.1 19.5 14.2 9.6 2029.0003 JAN 39.5 23.8 5.5 19.0 14.1 9.1 2029.0837 FEB 38.8 22.8 5.2 18.3 14.1 8.6 2029.1670 MAR 38.1 21.9 4.6 17.3 14.0 8.0 2029.2503 APR 37.7 21.0 3.8 17.4 13.8 7.5 2029.3337 MAY 36.9 20.0 3.6 17.5 13.7 7.6 2029.4170 JUN 35.9 19.2 3.5 17.6 13.7 7.8 2029.5003 JUL 34.7 18.3 3.3 17.5 13.6 8.3 2029.5837 AUG 33.3 17.4 3.2 17.7 13.5 8.6 2029.6670 SEP 31.6 16.5 2.6 18.1 13.4 8.5 2029.7503 OCT 29.7 15.5 2.0 17.9 13.2 8.6 2029.8337 NOV 27.1 14.8 1.6 17.6 12.9 8.5 2029.9170 DEC 24.5 13.8 1.6 17.3 12.6 8.5 2030.0003 JAN 22.1 12.6 1.3 16.3 12.2 8.4 2030.0837 FEB 20.3 11.5 0.9 14.8 11.8 8.4 2030.1670 MAR 19.2 10.5 0.6 13.8 11.4 8.3 2030.2503 APR 18.9 9.7 0.6 13.9 11.0 8.2 2030.3337 MAY 18.5 9.1 0.5 13.6 10.6 8.2 2030.4170 JUN 18.2 8.5 0.4 13.2 10.3 7.9 2030.5003 JUL 16.8 8.0 0.3 12.9 9.9 7.4 2030.5837 AUG 15.9 7.5 0.2 12.6 9.7 7.1 2030.6670 SEP 15.8 7.0 0.1 11.9 9.5 7.3 2030.7503 OCT 15.0 6.5 0.0 11.4 9.4 7.1