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% 2009.2503 APR 3.7 2.5 1.3 4.9 4.7 4.6 2009.3337 MAY 5.1 2.9 0.7 5.3 5.0 4.7 2009.4170 JUN 7.1 3.3 0.5 5.9 5.2 4.6 2009.5003 JUL 9.0 4.0 0.7 6.2 5.2 4.3 2009.5837 AUG 10.7 4.8 0.4 6.6 5.2 4.2 2009.6670 SEP 13.0 5.6 0.2 7.0 5.1 3.9 2009.7503 OCT 16.2 6.4 0.0 7.0 5.2 3.8 2009.8337 NOV 20.6 7.2 0.0 6.9 5.1 3.6 2009.9170 DEC 24.3 8.2 0.0 6.9 4.9 3.3 2010.0003 JAN 26.6 9.3 0.0 6.5 4.3 2.7 2010.0837 FEB 30.4 10.3 0.0 6.2 3.9 2.1 2010.1670 MAR 35.3 11.7 0.0 6.1 3.6 1.6 2010.2503 APR 40.9 13.5 0.0 6.3 3.3 0.8 2010.3337 MAY 47.3 15.2 0.0 7.3 3.5 0.5 2010.4170 JUN 54.0 17.0 0.0 8.2 3.7 0.6 2010.5003 JUL 59.0 19.3 0.0 8.1 3.7 0.4 2010.5837 AUG 62.9 21.8 0.0 7.8 3.5 0.1 2010.6670 SEP 69.0 24.3 0.0 6.7 3.0 -0.3 2010.7503 OCT 75.1 26.8 0.0 5.9 2.7 -0.4 2010.8337 NOV 82.5 29.0 0.0 5.2 2.7 -0.2 2010.9170 DEC 90.7 31.2 0.0 4.8 2.7 -0.1 2011.0003 JAN 98.0 33.6 0.0 5.6 3.0 0.3 2011.0837 FEB 104.2 35.8 0.0 7.3 3.9 1.9 2011.1670 MAR 111.0 37.9 0.0 8.1 4.9 2.7 2011.2503 APR 117.5 40.4 0.5 8.0 5.2 2.7 2011.3337 MAY 120.9 42.3 1.3 8.3 5.5 2.7 2011.4170 JUN 121.6 43.9 2.1 8.9 5.7 2.3 2011.5003 JUL 123.6 45.8 2.9 9.6 5.9 1.9 2011.5837 AUG 127.0 47.3 2.8 9.9 6.3 2.1 2011.6670 SEP 131.2 49.1 3.1 10.7 7.0 2.5 2011.7503 OCT 136.9 51.0 3.3 11.8 7.6 3.0 2011.8337 NOV 140.3 52.9 2.3 12.8 8.1 3.1 2011.9170 DEC 141.9 54.7 2.1 13.2 8.4 2.9 2012.0003 JAN 146.3 56.9 3.0 13.3 8.9 2.8 2012.0837 FEB 151.5 58.8 5.1 13.1 9.2 2.8 2012.1670 MAR 154.5 60.3 6.4 13.3 9.4 2.9 2012.2503 APR 156.9 61.7 6.4 13.6 9.2 2.8 2012.3337 MAY 159.6 62.8 6.3 14.1 9.0 2.3 2012.4170 JUN 162.0 64.1 6.5 14.8 9.5 2.7 2012.5003 JUL 164.0 65.5 6.9 15.3 10.4 4.1 2012.5837 AUG 166.3 66.9 8.6 15.8 11.1 5.4 2012.6670 SEP 168.1 68.4 10.1 15.7 11.2 6.0 2012.7503 OCT 167.1 68.6 10.7 15.1 11.0 6.0 2012.8337 NOV 166.1 69.0 11.9 15.0 10.9 6.2 2012.9170 DEC 167.4 69.8 13.5 14.6 10.8 6.1 2013.0003 JAN 168.1 70.0 15.3 13.4 10.3 5.5 2013.0837 FEB 166.2 70.2 17.6 12.7 10.1 5.6 2013.1670 MAR 163.4 71.3 20.8 12.1 9.2 5.1 2013.2503 APR 160.3 72.7 24.2 11.6 8.2 4.4 2013.3337 MAY 158.5 73.2 26.7 11.6 8.0 4.1 2013.4170 JUN 157.7 73.0 28.1 12.4 7.6 3.3 2013.5003 JUL 157.0 73.1 29.6 12.8 7.2 2.7 2013.5837 AUG 156.5 73.7 31.6 13.0 7.0 2.7 2013.6670 SEP 156.0 73.9 33.6 13.5 6.8 2.5 2013.7503 OCT 156.4 73.9 33.9 13.6 6.6 2.3 2013.8337 NOV 157.0 73.5 32.6 13.4 7.1 2.8 2013.9170 DEC 156.9 73.5 31.9 13.8 7.4 3.4 2014.0003 JAN 155.9 73.6 32.5 13.3 7.7 4.5 2014.0837 FEB 152.9 72.6 31.8 11.8 7.8 4.8 2014.1670 MAR 148.0 70.2 29.3 11.8 8.0 4.9 2014.2503 APR 144.3 68.0 26.7 12.3 8.3 5.1 2014.3337 MAY 140.6 66.4 24.6 12.7 8.7 5.5 2014.4170 JUN 135.8 64.7 22.5 13.7 9.2 6.2 2014.5003 JUL 132.2 62.8 21.3 14.3 9.6 6.6 2014.5837 AUG 128.7 60.9 20.4 13.3 9.1 6.2 2014.6670 SEP 125.3 60.1 20.6 12.6 8.7 5.8 2014.7503 OCT 122.9 60.2 21.7 12.4 8.9 5.8 2014.8337 NOV 119.5 59.8 22.6 12.2 8.8 5.4 2014.9170 DEC 115.9 58.4 22.5 12.6 8.6 5.1 2015.0003 JAN 113.3 57.3 22.1 12.9 8.5 4.8 2015.0837 FEB 110.8 56.9 22.4 13.9 8.9 4.7 2015.1670 MAR 108.9 56.1 21.1 15.6 10.0 5.5 2015.2503 APR 106.6 55.2 19.7 16.7 10.7 6.2 2015.3337 MAY 104.3 54.3 19.1 17.6 11.4 7.2 2015.4170 JUN 100.4 53.1 18.2 18.1 12.0 7.2 2015.5003 JUL 95.5 52.0 17.2 18.0 12.4 7.7 2015.5837 AUG 91.6 51.2 16.8 17.8 12.9 8.5 2015.6670 SEP 87.6 50.0 16.7 17.4 13.3 9.3 2015.7503 OCT 82.7 48.0 16.3 18.3 13.6 10.1 2015.8337 NOV 77.8 45.7 15.8 19.1 14.2 10.6 2015.9170 DEC 74.1 43.1 14.5 19.7 14.9 11.0 2016.0003 JAN 70.4 40.8 13.3 20.5 15.3 11.1 2016.0837 FEB 65.7 39.2 13.2 20.4 15.1 10.6 2016.1670 MAR 63.1 37.8 11.9 20.4 14.9 10.3 2016.2503 APR 62.9 36.7 9.1 20.6 14.5 10.0 2016.3337 MAY 63.8 35.9 7.1 20.7 14.0 9.4 2016.4170 JUN 64.5 35.3 6.5 21.2 13.7 8.4 2016.5003 JUL 63.7 34.1 5.6 21.4 13.2 7.2 2016.5837 AUG 63.7 33.1 5.0 21.4 12.4 6.4 2016.6670 SEP 62.9 32.1 4.2 21.5 12.1 6.0 2016.7503 OCT 60.2 30.7 3.3 21.6 12.0 5.8 2016.8337 NOV 58.2 29.8 2.9 21.2 11.7 5.5 2016.9170 DEC 57.1 29.2 2.4 20.2 11.2 5.2 2017.0003 JAN 57.1 28.7 2.1 19.2 11.0 5.3 2017.0837 FEB 57.0 28.4 2.1 18.7 11.3 6.0 2017.1670 MAR 55.2 27.9 2.4 18.9 12.0 6.8 2017.2503 APR 52.4 27.2 3.1 18.8 12.4 7.1 2017.3337 MAY 48.8 26.0 3.7 19.0 12.9 7.8 2017.4170 JUN 46.2 24.8 3.5 19.1 13.4 8.7 2017.5003 JUL 46.3 24.3 3.6 19.1 13.8 9.5 2017.5837 AUG 45.7 23.7 4.0 19.1 13.9 10.0 2017.6670 SEP 42.7 22.2 4.2 19.5 14.0 10.5 2017.7503 OCT 40.1 20.7 3.4 19.8 14.1 10.4 2017.8337 NOV 38.9 19.9 3.1 19.8 14.2 10.1 2017.9170 DEC 38.1 19.0 3.1 19.8 14.7 10.0 2018.0003 JAN 36.3 17.8 2.9 19.9 15.5 10.2 2018.0837 FEB 33.5 16.7 2.4 19.7 16.1 10.3 2018.1670 MAR 30.7 15.6 1.6 19.9 16.3 9.8 2018.2503 APR 29.4 14.9 1.5 19.8 16.2 9.4 2018.3337 MAY 28.1 14.2 1.4 19.3 15.8 9.3 2018.4170 JUN 26.8 13.6 1.3 18.7 15.5 9.3 2018.5003 JUL 25.5 12.9 1.2 18.9 15.7 10.0 2018.5837 AUG 24.2 12.3 1.1 19.4 16.2 10.8 2018.6670 SEP 23.0 11.6 1.0 20.0 16.5 11.1 2018.7503 OCT 21.8 11.0 0.9 20.1 16.6 11.3 2018.8337 NOV 20.7 10.4 0.8 19.8 16.3 11.2 2018.9170 DEC 19.6 9.8 0.7 18.8 15.5 10.7 2019.0003 JAN 18.5 9.3 0.6 17.8 14.7 10.3 2019.0837 FEB 17.5 8.8 0.5 16.8 13.8 9.8 2019.1670 MAR 16.6 8.3 0.4 15.9 13.0 9.3 2019.2503 APR 15.8 7.9 0.3 15.0 12.3 8.9 2019.3337 MAY 15.0 7.5 0.3 14.2 11.6 8.5 2019.4170 JUN 14.3 7.1 0.2 13.4 11.0 8.1 2019.5003 JUL 13.7 6.8 0.1 12.7 10.4 7.8 2019.5837 AUG 13.2 6.6 0.1 12.2 9.9 7.5 2019.6670 SEP 12.8 6.3 0.1 11.7 9.5 7.3 2019.7503 OCT 12.5 6.2 0.0 11.3 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