TABLE 5 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 25 WITH A MEAN CYCLE GIVEN FOR CYCLE 26 TIME 10.7 CM SOLAR FLUX (F10.7) GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 75.0% 50% 5.0% 95.0% 50% 5.0% 2019.9173 DEC 69.5 69.5 69.3 5.7 5.5 5.2 2020.0007 JAN 70.0 69.8 69.2 5.9 5.6 5.0 2020.0840 FEB 70.4 70.1 69.2 6.0 5.6 5.0 2020.1673 MAR 71.0 70.5 69.4 6.0 5.5 4.9 2020.2507 APR 71.5 70.9 69.4 6.1 5.6 4.9 2020.3340 MAY 72.0 71.4 69.4 6.2 5.6 4.8 2020.4173 JUN 72.8 72.0 69.2 6.6 5.6 4.5 2020.5007 JUL 73.8 72.7 69.3 7.1 5.6 4.3 2020.5840 AUG 75.3 73.5 69.5 7.2 5.6 4.1 2020.6673 SEP 76.5 74.4 69.4 7.4 5.8 4.1 2020.7507 OCT 77.8 75.4 69.4 7.5 6.0 4.2 2020.8340 NOV 79.7 76.7 69.3 7.6 6.0 4.4 2020.9173 DEC 81.4 78.1 69.0 7.5 5.9 4.1 2021.0007 JAN 83.5 79.7 68.9 7.5 5.8 3.8 2021.0840 FEB 86.1 81.4 68.8 7.5 5.8 3.7 2021.1673 MAR 88.8 83.4 68.2 8.0 5.7 3.2 2021.2507 APR 91.3 85.4 67.7 8.9 5.8 3.0 2021.3340 MAY 93.6 87.6 67.5 9.8 6.1 3.0 2021.4173 JUN 95.8 89.9 67.8 10.0 6.2 3.0 2021.5007 JUL 98.7 92.5 68.6 9.9 6.4 3.0 2021.5840 AUG 102.1 95.1 68.9 9.4 6.4 3.0 2021.6673 SEP 105.5 97.7 69.0 8.8 6.4 3.2 2021.7507 OCT 107.6 100.3 69.8 8.2 6.3 3.4 2021.8340 NOV 112.0 103.1 70.9 8.4 6.4 3.5 2021.9173 DEC 115.7 106.0 71.3 9.3 6.6 3.9 2022.0007 JAN 120.1 108.9 72.1 10.5 7.0 4.6 2022.0840 FEB 124.1 111.8 73.3 10.9 7.5 5.2 2022.1673 MAR 125.5 114.7 74.6 10.8 7.9 5.4 2022.2507 APR 130.4 117.8 76.3 11.0 8.2 5.7 2022.3340 MAY 136.4 120.7 77.6 11.6 8.4 5.4 2022.4173 JUN 139.7 123.1 79.3 12.2 8.5 4.9 2022.5007 JUL 140.9 125.2 80.6 12.4 8.7 4.9 2022.5840 AUG 142.0 127.3 81.4 12.9 9.0 4.9 2022.6673 SEP 144.9 129.7 82.2 13.7 9.4 5.1 2022.7507 OCT 150.7 132.0 81.7 14.4 9.6 4.8 2022.8340 NOV 156.5 134.2 81.8 14.7 9.7 4.4 2022.9173 DEC 161.0 136.1 82.3 14.6 10.0 4.1 2023.0007 JAN 161.3 137.8 82.5 14.2 10.3 4.0 2023.0840 FEB 159.3 139.4 83.6 14.0 10.3 3.9 2023.1673 MAR 158.3 140.8 85.9 14.3 10.2 3.9 2023.2507 APR 160.2 141.9 87.1 15.1 10.1 3.6 2023.3340 MAY 164.5 142.7 86.5 15.3 10.1 3.5 2023.4173 JUN 168.6 143.4 85.3 15.0 10.3 4.1 2023.5007 JUL 171.1 143.7 85.1 14.9 10.5 4.7 2023.5840 AUG 170.5 143.9 85.7 14.5 10.5 5.0 2023.6673 SEP 166.9 144.3 86.8 13.9 10.3 5.0 2023.7507 OCT 164.0 144.5 88.7 13.7 10.2 5.1 2023.8340 NOV 162.3 144.6 90.7 13.8 10.3 5.2 2023.9173 DEC 164.2 144.1 92.0 13.5 10.2 5.1 2024.0007 JAN 164.3 143.0 92.9 13.3 10.0 5.4 2024.0840 FEB 162.0 142.4 93.7 12.9 9.7 5.7 2024.1673 MAR 159.2 142.1 94.5 12.9 9.3 5.6 2024.2507 APR 157.0 142.4 95.5 13.1 9.1 5.5 2024.3340 MAY 157.2 142.8 96.8 14.3 9.2 5.3 2024.4173 JUN 158.6 142.8 98.2 15.2 9.2 5.2 2024.5007 JUL 160.7 142.7 99.1 15.7 9.3 5.6 2024.5840 AUG 161.0 142.4 99.5 16.6 9.4 5.7 2024.6673 SEP 160.7 142.0 99.9 16.8 9.4 5.6 2024.7507 OCT 161.4 141.9 99.3 16.3 9.5 5.8 2024.8340 NOV 160.4 141.6 98.4 16.3 9.7 6.0 2024.9173 DEC 157.7 140.9 98.2 15.4 9.6 6.1 2025.0007 JAN 155.8 139.8 98.6 13.8 9.5 5.8 2025.0840 FEB 154.3 138.3 98.5 13.8 9.7 5.7 2025.1673 MAR 153.1 136.7 98.2 14.2 10.0 5.7 2025.2507 APR 153.3 135.2 97.0 14.4 10.2 6.0 2025.3340 MAY 153.5 134.0 96.4 15.2 10.5 6.6 2025.4173 JUN 153.4 132.6 96.5 15.7 10.8 6.9 2025.5007 JUL 151.7 131.0 96.1 16.3 10.6 6.7 2025.5840 AUG 148.9 129.2 96.1 16.6 10.6 6.9 2025.6673 SEP 146.6 127.8 96.4 17.0 10.8 7.3 2025.7507 OCT 145.4 126.6 96.0 17.0 10.9 7.1 2025.8340 NOV 144.7 125.6 96.0 16.3 10.9 6.9 2025.9173 DEC 140.8 124.1 96.2 15.3 10.8 6.8 2026.0007 JAN 137.0 122.3 94.9 14.0 10.9 6.7 2026.0840 FEB 134.1 121.2 94.2 13.5 11.3 7.1 2026.1673 MAR 131.9 120.3 92.6 14.3 11.7 7.6 2026.2507 APR 131.1 119.0 90.6 15.0 12.0 8.5 2026.3340 MAY 128.0 117.5 90.0 15.3 12.2 8.2 2026.4173 JUN 125.7 115.8 89.8 14.9 12.4 8.5 2026.5007 JUL 125.0 114.2 88.9 15.9 12.6 9.0 2026.5840 AUG 125.0 112.7 87.8 17.3 12.7 9.3 2026.6673 SEP 121.2 110.8 86.5 18.1 12.8 9.9 2026.7507 OCT 117.0 108.9 85.5 18.4 13.0 9.3 2026.8340 NOV 114.7 107.2 85.2 18.3 13.3 9.2 2026.9173 DEC 113.4 105.6 85.1 18.4 13.5 8.9 2027.0007 JAN 111.7 104.0 84.6 18.3 13.6 8.5 2027.0840 FEB 109.6 102.5 84.6 18.5 13.5 8.4 2027.1673 MAR 108.2 101.2 84.2 18.9 13.4 8.3 2027.2507 APR 108.2 99.8 82.8 19.2 13.2 8.0 2027.3340 MAY 106.2 98.3 81.0 19.7 12.9 7.0 2027.4173 JUN 103.3 97.0 80.0 20.0 12.4 6.0 2027.5007 JUL 101.8 95.8 78.8 20.3 12.0 5.6 2027.5840 AUG 101.1 94.6 77.9 20.6 11.8 5.5 2027.6673 SEP 99.9 93.6 77.4 20.8 11.7 5.4 2027.7507 OCT 100.1 92.7 77.2 20.6 11.5 5.4 2027.8340 NOV 99.7 91.8 76.6 19.9 11.3 5.3 2027.9173 DEC 98.5 90.7 75.7 18.9 11.0 5.5 2028.0007 JAN 97.4 89.7 74.6 18.2 11.0 5.8 2028.0840 FEB 95.9 88.9 73.7 18.0 11.2 5.9 2028.1673 MAR 95.8 88.0 73.3 17.8 11.4 5.4 2028.2507 APR 95.8 86.9 73.1 17.7 11.7 4.9 2028.3340 MAY 94.3 85.9 72.8 17.6 12.0 5.0 2028.4173 JUN 92.0 85.1 72.5 18.0 12.2 5.5 2028.5007 JUL 90.8 84.3 72.3 18.4 12.2 6.1 2028.5840 AUG 89.1 83.4 72.2 18.7 12.1 6.5 2028.6673 SEP 87.4 82.4 71.8 18.8 12.0 6.5 2028.7507 OCT 86.4 81.4 71.5 18.6 12.0 6.7 2028.8340 NOV 86.6 80.7 71.4 18.4 12.1 6.8 2028.9173 DEC 85.3 80.1 71.2 18.1 12.5 7.2 2029.0007 JAN 83.4 79.5 71.1 17.6 12.7 7.5 2029.0840 FEB 81.9 78.7 70.8 16.7 12.7 7.5 2029.1673 MAR 81.7 78.0 70.4 16.9 12.5 7.4 2029.2507 APR 81.3 77.3 70.1 16.9 12.1 7.1 2029.3340 MAY 80.3 76.6 70.0 16.9 11.8 6.7 2029.4173 JUN 79.8 76.1 69.9 16.9 11.8 6.2 2029.5007 JUL 79.7 75.6 69.9 17.2 11.8 6.1 2029.5840 AUG 79.4 75.2 69.7 17.6 12.0 6.5 2029.6673 SEP 78.9 74.7 69.4 17.6 11.9 6.6 2029.7507 OCT 78.4 74.2 69.4 17.3 11.7 6.5 2029.8340 NOV 77.6 73.5 69.2 17.0 11.5 6.5 2029.9173 DEC 75.7 72.9 68.9 15.9 11.0 6.4 2030.0007 JAN 74.5 72.3 68.5 14.4 10.3 6.4 2030.0840 FEB 73.9 71.9 68.2 13.1 9.8 6.3 2030.1673 MAR 74.0 71.6 68.1 13.1 9.4 6.1 2030.2507 APR 73.8 71.2 68.0 12.8 9.1 6.0 2030.3340 MAY 73.1 70.9 67.9 12.5 8.9 5.9 2030.4173 JUN 72.4 70.6 67.5 12.3 8.7 5.7 2030.5007 JUL 72.2 70.3 67.3 12.0 8.5 5.3 2030.5840 AUG 71.8 70.0 67.1 11.2 8.1 4.7 2030.6673 SEP 71.7 69.8 66.9 10.7 7.9 4.2 2030.7507 OCT 71.4 69.6 67.0 10.5 7.8 4.0 2030.8340 NOV 71.4 69.6 67.0 10.6 7.9 4.0 2030.9173 DEC 71.6 69.8 67.0 10.8 8.0 3.9 2031.0007 JAN 72.2 70.1 67.0 11.2 8.2 3.9 2031.0840 FEB 72.9 70.5 67.2 11.4 8.4 3.9 2031.1673 MAR 72.9 70.9 67.2 11.6 8.5 3.6 2031.2507 APR 73.0 71.3 67.4 11.8 8.6 3.5 2031.3340 MAY 74.1 71.9 67.6 11.9 8.8 3.4 2031.4173 JUN 75.6 72.6 67.7 12.1 8.9 3.4 2031.5007 JUL 76.1 73.4 67.8 12.4 9.2 3.3 2031.5840 AUG 76.9 74.2 68.0 12.8 9.5 3.4 2031.6673 SEP 78.2 75.2 68.1 13.2 9.9 3.8 2031.7507 OCT 80.0 76.4 68.4 13.8 10.4 4.2 2031.8340 NOV 82.5 77.8 68.5 14.6 10.6 4.5 2031.9173 DEC 85.7 79.4 68.5 15.7 10.9 4.6 2032.0007 JAN 88.4 81.1 68.5 16.1 11.1 4.8 2032.0840 FEB 91.6 83.1 68.5 16.3 11.3 5.0 2032.1673 MAR 94.6 85.2 68.4 16.9 11.4 5.0 2032.2507 APR 97.2 87.5 68.6 18.0 11.6 5.2 2032.3340 MAY 99.1 89.9 68.7 18.9 11.9 5.4 2032.4173 JUN 103.2 92.5 69.0 19.1 12.1 5.6 2032.5007 JUL 108.1 95.3 69.3 19.2 12.3 5.8 2032.5840 AUG 112.2 98.1 69.4 19.0 12.6 6.0 2032.6673 SEP 116.5 100.8 69.6 18.6 12.7 6.1 2032.7507 OCT 120.0 103.6 70.1 18.5 12.7 6.1 2032.8340 NOV 122.7 106.7 70.8 18.9 12.8 6.1 2032.9173 DEC 125.5 109.8 71.0 18.8 12.9 6.3 2033.0007 JAN 129.4 113.0 71.4 17.8 13.0 6.5 2033.0840 FEB 133.2 116.2 71.7 17.9 13.2 6.7 2033.1673 MAR 137.5 119.2 72.3 18.4 13.4 7.0 2033.2507 APR 143.0 122.5 73.1 19.1 13.7 7.0 2033.3340 MAY 148.7 125.6 73.5 19.6 14.2 7.0 2033.4173 JUN 153.5 128.0 74.3 20.3 14.5 7.0 2033.5007 JUL 157.2 130.2 74.9 20.3 14.5 7.2 2033.5840 AUG 163.0 132.5 75.3 20.3 14.5 7.6 2033.6673 SEP 169.0 135.1 75.9 20.5 14.6 8.0 2033.7507 OCT 173.9 137.6 76.2 20.8 14.8 8.0 2033.8340 NOV 179.8 139.9 76.5 21.2 14.8 8.0 2033.9173 DEC 181.7 141.8 76.5 21.3 14.6 8.3 2034.0007 JAN 184.2 143.7 76.5 21.4 14.6 8.6 2034.0840 FEB 185.0 145.3 76.8 21.6 14.6 8.5 2034.1673 MAR 184.8 146.8 77.3 22.0 14.5 8.4 2034.2507 APR 184.0 148.0 77.8 22.7 14.4 8.6 2034.3340 MAY 183.8 148.7 78.5 22.4 14.1 8.6 2034.4173 JUN 185.2 149.3 79.8 21.3 13.8 8.6 2034.5007 JUL 186.7 149.6 80.6 20.6 13.7 8.4 2034.5840 AUG 187.4 149.9 81.6 20.1 13.6 8.1 2034.6673 SEP 187.1 150.2 83.1 19.7 13.5 7.7 2034.7507 OCT 186.0 150.3 84.6 19.6 13.5 7.5 2034.8340 NOV 186.2 150.3 86.2 19.3 13.5 7.8 2034.9173 DEC 184.1 149.6 87.0 19.1 13.7 7.8 2035.0007 JAN 179.8 148.5 88.2 18.9 13.9 7.6 2035.0840 FEB 176.9 147.7 89.8 18.9 14.0 7.5 2035.1673 MAR 178.6 147.5 90.9 19.5 13.9 7.3 2035.2507 APR 178.2 147.8 93.0 20.4 14.0 7.1 2035.3340 MAY 175.8 148.1 94.3 22.0 14.4 7.1 2035.4173 JUN 173.7 148.1 95.7 23.4 14.6 7.0 2035.5007 JUL 172.3 147.9 96.0 24.0 14.8 7.2 2035.5840 AUG 171.0 147.5 95.6 25.1 15.1 7.3 2035.6673 SEP 169.2 147.1 95.5 25.7 15.3 7.1 2035.7507 OCT 165.4 147.0 97.0 24.9 15.3 7.1 2035.8340 NOV 162.4 146.6 97.8 24.8 15.4 6.9 2035.9173 DEC 159.9 145.8 97.3 24.0 15.3 6.4 2036.0007 JAN 157.8 144.6 96.5 22.2 15.3 6.1 2036.0840 FEB 155.7 143.0 96.4 22.5 15.5 6.2 2036.1673 MAR 155.3 141.4 96.9 23.2 15.6 6.4 2036.2507 APR 155.2 140.0 96.4 23.2 15.7 6.6 2036.3340 MAY 153.7 138.7 95.7 22.7 15.7 6.9 2036.4173 JUN 150.5 137.3 96.3 22.0 15.6 7.4 2036.5007 JUL 146.7 135.5 97.2 21.9 15.7 7.6 2036.5840 AUG 143.8 133.6 96.3 22.7 15.9 7.9 2036.6673 SEP 140.5 131.8 94.6 23.7 16.2 8.4 2036.7507 OCT 137.7 130.5 93.8 23.9 16.4 8.7 2036.8340 NOV 136.8 129.2 93.6 23.8 16.6 9.1 2036.9173 DEC 136.5 127.6 91.8 23.8 16.6 9.5 2037.0007 JAN 135.2 125.7 88.5 23.4 16.5 9.9 2037.0840 FEB 133.9 124.5 88.0 22.5 16.5 10.3 2037.1673 MAR 134.1 123.4 88.7 22.7 16.4 10.7 2037.2507 APR 132.8 122.0 87.3 23.0 16.5 11.2 2037.3340 MAY 130.7 120.4 86.3 23.0 16.6 11.6 2037.4173 JUN 129.7 118.6 85.7 22.4 16.7 11.8 2037.5007 JUL 129.1 116.8 84.9 21.5 16.5 11.9 2037.5840 AUG 126.6 115.1 83.7 21.2 16.4 11.8 2037.6673 SEP 125.2 113.2 82.7 21.7 16.2 11.5 2037.7507 OCT 124.7 111.3 82.3 21.7 16.0 11.4 2037.8340 NOV 123.6 109.6 82.2 22.1 16.1 11.5 2037.9173 DEC 122.1 108.1 82.0 22.5 16.2 11.3 2038.0007 JAN 120.1 106.5 81.0 22.3 16.2 11.1 2038.0840 FEB 118.3 104.9 80.6 22.3 16.0 10.9 2038.1673 MAR 116.2 103.4 80.6 22.7 15.8 10.7 2038.2507 APR 114.3 101.9 80.0 22.9 15.5 10.7 2038.3340 MAY 111.1 100.2 79.1 23.4 15.3 10.5 2038.4173 JUN 109.5 98.8 77.7 24.0 15.1 10.2 2038.5007 JUL 107.9 97.5 75.6 24.7 14.9 10.1 2038.5840 AUG 106.4 96.3 74.6 25.3 14.8 10.0 2038.6673 SEP 104.4 95.2 74.1 25.5 14.8 10.2 2038.7507 OCT 103.0 94.3 73.8 25.3 14.7 10.5 2038.8340 NOV 102.0 93.3 73.5 24.8 14.5 10.3 2038.9173 DEC 100.5 92.1 73.1 23.9 14.3 10.0 2039.0007 JAN 98.9 91.0 72.7 23.0 14.1 9.4 2039.0840 FEB 98.2 90.0 72.0 22.5 14.2 8.8 2039.1673 MAR 97.9 89.0 71.4 22.1 14.2 8.1 2039.2507 APR 97.5 87.8 71.1 21.8 14.4 7.5 2039.3340 MAY 97.0 86.8 70.8 21.4 14.5 7.4 2039.4173 JUN 95.7 86.0 70.5 20.8 14.4 7.7 2039.5007 JUL 94.8 85.1 70.6 20.0 14.3 8.1 2039.5840 AUG 93.0 84.1 70.4 20.0 14.1 8.5 2039.6673 SEP 90.8 83.0 69.9 20.2 13.9 8.5 2039.7507 OCT 89.4 82.0 69.6 19.8 13.8 8.5 2039.8340 NOV 88.2 81.3 69.5 19.4 13.6 8.4 2039.9173 DEC 86.7 80.7 69.5 18.9 13.6 8.4 2040.0007 JAN 85.9 80.0 69.3 18.2 13.6 8.3 2040.0840 FEB 85.2 79.3 69.1 17.3 13.5 8.0 2040.1673 MAR 83.9 78.5 68.8 17.3 13.4 7.6 2040.2507 APR 82.8 77.8 68.6 17.4 13.2 7.1 2040.3340 MAY 81.8 77.2 68.4 17.5 13.1 6.7 2040.4173 JUN 81.2 76.6 68.4 17.5 13.0 6.6 2040.5007 JUL 80.7 76.1 68.5 17.7 12.8 6.5 2040.5840 AUG 80.5 75.6 68.5 18.0 12.8 6.6 2040.6673 SEP 79.2 75.1 68.5 17.9 12.6 6.5 2040.7507 OCT 77.9 74.6 68.4 17.6 12.3 6.4 2040.8340 NOV 77.2 73.9 68.3 17.3 12.1 6.4 2040.9173 DEC 76.6 73.2 68.1 16.3 11.7 6.2 2041.0007 JAN 75.8 72.6 67.8 14.9 11.2 6.1 2041.0840 FEB 75.3 72.1 67.7 13.8 10.9 6.1 2041.1673 MAR 74.4 71.8 67.6 13.9 10.5 6.1 2041.2507 APR 73.3 71.5 67.5 13.6 10.2 6.2 2041.3340 MAY 73.2 71.1 67.3 13.2 9.8 6.2 2041.4173 JUN 72.4 70.8 67.1 12.9 9.5 6.0 2041.5007 JUL 71.7 70.5 67.1 12.6 9.3 5.9 2041.5840 AUG 71.6 70.2 67.0 11.9 9.1 5.7 2041.6673 SEP 71.8 70.0 67.0 11.4 8.9 5.2