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% 2020.3337 MAY 71.0 70.9 70.3 5.7 5.2 4.9 2020.4170 JUN 71.6 71.4 70.6 6.2 5.3 4.5 2020.5003 JUL 72.6 72.0 70.4 6.6 5.2 4.2 2020.5837 AUG 73.6 72.7 70.3 7.2 5.2 4.1 2020.6670 SEP 74.9 73.5 70.3 7.3 5.2 4.0 2020.7503 OCT 76.0 74.3 70.3 7.5 5.4 4.0 2020.8337 NOV 77.1 75.4 70.6 7.7 5.7 4.1 2020.9170 DEC 78.4 76.6 71.1 7.8 5.8 4.3 2021.0003 JAN 80.6 78.0 70.9 7.8 5.6 3.8 2021.0837 FEB 83.0 79.6 70.7 7.9 5.6 3.4 2021.1670 MAR 86.1 81.3 70.9 8.4 5.6 3.4 2021.2503 APR 89.2 83.2 70.8 9.0 5.6 3.1 2021.3337 MAY 91.7 85.3 70.8 10.1 5.8 2.9 2021.4170 JUN 94.1 87.4 71.1 10.9 6.0 2.9 2021.5003 JUL 96.8 89.7 71.6 11.0 6.1 2.8 2021.5837 AUG 100.3 92.3 72.2 11.0 6.2 2.8 2021.6670 SEP 104.4 94.9 72.8 10.5 6.2 2.8 2021.7503 OCT 107.9 97.5 73.3 9.9 6.1 2.9 2021.8337 NOV 110.7 100.1 74.5 9.3 6.1 3.1 2021.9170 DEC 113.8 102.9 76.0 8.8 6.1 3.2 2022.0003 JAN 116.7 105.8 76.3 8.8 6.4 3.6 2022.0837 FEB 119.0 108.7 76.5 10.0 6.7 4.2 2022.1670 MAR 121.5 111.6 77.1 10.4 7.2 4.8 2022.2503 APR 125.1 114.5 78.1 10.3 7.6 5.0 2022.3337 MAY 127.5 117.6 79.6 10.5 7.9 5.3 2022.4170 JUN 131.2 120.5 81.5 11.1 8.1 4.9 2022.5003 JUL 135.2 122.9 82.8 11.8 8.2 4.5 2022.5837 AUG 137.3 125.0 83.0 11.9 8.4 4.4 2022.6670 SEP 141.4 127.1 83.1 12.5 8.8 4.6 2022.7503 OCT 144.3 129.6 84.3 13.4 9.2 4.9 2022.8337 NOV 147.9 132.0 84.9 14.1 9.4 4.5 2022.9170 DEC 151.6 134.2 85.2 14.4 9.4 4.1 2023.0003 JAN 153.7 136.2 86.4 14.3 9.8 3.8 2023.0837 FEB 154.8 138.0 88.8 13.9 10.0 3.7 2023.1670 MAR 156.2 139.6 91.6 14.0 10.0 3.6 2023.2503 APR 159.3 141.1 94.0 14.4 10.0 3.5 2023.3337 MAY 162.2 142.2 95.2 15.2 9.9 3.3 2023.4170 JUN 165.5 143.0 94.8 15.4 9.9 3.3 2023.5003 JUL 169.5 143.8 93.6 15.0 10.1 3.7 2023.5837 AUG 171.2 144.1 93.4 14.8 10.2 4.3 2023.6670 SEP 167.9 144.4 94.2 14.3 10.2 4.6 2023.7503 OCT 164.3 144.7 95.2 13.7 10.0 4.6 2023.8337 NOV 163.0 145.0 96.9 13.7 10.0 4.8 2023.9170 DEC 164.1 145.1 98.7 13.5 10.1 4.9 2024.0003 JAN 165.1 144.5 99.8 12.8 9.8 4.7 2024.0837 FEB 165.8 143.5 100.6 12.5 9.7 4.8 2024.1670 MAR 167.1 142.8 101.6 12.3 9.2 5.0 2024.2503 APR 166.8 142.6 102.9 12.2 8.7 4.8 2024.3337 MAY 166.0 142.9 104.1 12.4 8.6 4.6 2024.4170 JUN 164.1 143.3 105.1 13.2 8.6 4.3 2024.5003 JUL 164.3 143.4 105.7 14.1 8.6 4.2 2024.5837 AUG 165.7 143.3 102.8 14.5 8.7 4.5 2024.6670 SEP 164.7 143.0 99.9 15.2 8.6 4.5 2024.7503 OCT 164.6 142.6 96.8 15.3 8.5 4.3 2024.8337 NOV 161.9 142.4 95.2 14.8 8.7 4.5 2024.9170 DEC 160.9 142.1 94.1 14.7 8.8 4.5 2025.0003 JAN 159.9 141.4 92.6 13.9 8.7 5.5 2025.0837 FEB 160.0 140.3 90.9 12.5 8.7 5.7 2025.1670 MAR 155.1 138.8 89.0 12.5 9.0 6.0 2025.2503 APR 153.9 137.2 88.3 13.0 9.4 6.1 2025.3337 MAY 154.0 135.6 87.3 13.6 9.6 6.4 2025.4170 JUN 154.1 134.4 86.9 14.7 10.0 6.6 2025.5003 JUL 153.2 133.0 86.7 15.6 10.4 6.9 2025.5837 AUG 150.8 131.4 86.6 16.4 10.2 6.8 2025.6670 SEP 147.9 129.6 87.0 16.8 10.3 6.6 2025.7503 OCT 145.9 128.1 87.7 17.4 10.6 6.7 2025.8337 NOV 145.0 127.0 88.0 17.3 10.6 6.5 2025.9170 DEC 142.0 126.0 88.6 16.7 10.6 6.3 2026.0003 JAN 138.2 124.5 89.4 15.7 10.6 6.2 2026.0837 FEB 136.2 122.7 89.2 14.4 10.7 6.1 2026.1670 MAR 135.4 121.6 89.0 13.9 11.2 6.6 2026.2503 APR 133.2 120.6 88.9 14.2 11.6 7.2 2026.3337 MAY 129.2 119.3 88.6 14.9 11.9 8.1 2026.4170 JUN 126.1 117.8 87.9 15.0 12.0 7.8 2026.5003 JUL 126.0 116.1 87.6 14.7 12.2 8.0 2026.5837 AUG 126.3 114.5 87.1 15.7 12.4 8.6 2026.6670 SEP 126.1 112.9 86.1 17.1 12.5 8.9 2026.7503 OCT 124.5 111.1 84.8 17.9 12.6 9.8 2026.8337 NOV 121.2 109.1 83.7 18.4 12.9 9.4 2026.9170 DEC 118.1 107.4 82.8 18.2 13.1 9.1 2027.0003 JAN 115.9 105.9 82.0 18.7 13.3 8.8 2027.0837 FEB 114.2 104.3 81.4 18.6 13.4 8.4 2027.1670 MAR 112.0 102.8 81.2 18.7 13.3 8.2 2027.2503 APR 110.4 101.5 80.6 19.2 13.2 8.2 2027.3337 MAY 108.0 100.1 79.9 19.5 13.0 8.0 2027.4170 JUN 106.6 98.5 79.1 20.0 12.7 7.0 2027.5003 JUL 104.9 97.2 78.3 20.5 12.3 6.1 2027.5837 AUG 102.4 96.0 77.4 20.9 12.0 5.9 2027.6670 SEP 101.0 94.9 76.5 21.2 11.8 5.8 2027.7503 OCT 100.9 93.8 76.0 21.5 11.8 5.7 2027.8337 NOV 101.1 93.0 75.8 21.2 11.5 5.6 2027.9170 DEC 100.6 92.0 75.3 20.5 11.2 5.5 2028.0003 JAN 100.0 91.0 74.4 19.5 11.0 5.7 2028.0837 FEB 99.2 90.0 73.7 18.8 10.9 6.0 2028.1670 MAR 98.3 89.2 72.9 18.5 11.2 6.2 2028.2503 APR 98.1 88.2 72.6 18.2 11.2 5.5 2028.3337 MAY 97.8 87.1 72.4 18.0 11.5 4.9 2028.4170 JUN 96.6 86.1 72.3 17.8 11.7 5.0 2028.5003 JUL 94.2 85.3 72.0 17.6 11.9 5.5 2028.5837 AUG 92.9 84.5 71.9 18.0 11.8 6.0 2028.6670 SEP 91.2 83.6 71.7 18.2 11.7 6.3 2028.7503 OCT 89.1 82.5 71.4 18.3 11.5 6.3 2028.8337 NOV 87.6 81.5 71.1 18.1 11.5 6.4 2028.9170 DEC 87.3 80.9 71.0 18.0 11.7 6.6 2029.0003 JAN 86.4 80.2 70.9 17.7 12.0 7.0 2029.0837 FEB 84.5 79.5 70.9 17.1 12.2 7.2 2029.1670 MAR 82.9 78.7 70.7 16.3 12.2 7.1 2029.2503 APR 81.9 78.0 70.5 16.3 11.8 6.9 2029.3337 MAY 81.1 77.3 70.2 16.3 11.5 6.7 2029.4170 JUN 80.5 76.7 70.0 16.3 11.3 6.4 2029.5003 JUL 80.3 76.1 70.0 16.3 11.2 5.8 2029.5837 AUG 79.9 75.7 69.8 16.7 11.3 5.7 2029.6670 SEP 79.6 75.2 69.6 17.1 11.4 6.1 2029.7503 OCT 79.4 74.8 68.9 17.1 11.3 6.5 2029.8337 NOV 78.3 74.2 68.8 16.9 11.2 6.6 2029.9170 DEC 77.4 73.6 68.6 16.6 10.9 6.5 2030.0003 JAN 75.3 72.9 68.4 15.5 10.5 6.4 2030.0837 FEB 73.9 72.4 68.1 13.9 9.9 6.3 2030.1670 MAR 73.7 71.9 68.1 12.7 9.5 6.0 2030.2503 APR 74.0 71.6 68.0 12.8 9.1 5.9 2030.3337 MAY 73.5 71.3 67.8 12.5 8.7 5.8 2030.4170 JUN 72.8 70.9 67.6 12.2 8.5 5.7 2030.5003 JUL 72.2 70.6 67.7 12.0 8.4 5.6 2030.5837 AUG 72.1 70.3 67.5 11.7 8.2 5.2 2030.6670 SEP 71.5 70.0 67.2 11.0 7.9 4.6 2030.7503 OCT 71.3 69.8 66.9 10.5 7.7 4.1 2030.8337 NOV 71.2 69.6 66.9 10.2 7.5 3.8 2030.9170 DEC 71.2 69.7 66.9 10.3 7.5 3.9 2031.0003 JAN 71.4 69.8 66.9 10.6 7.7 3.7 2031.0837 FEB 72.0 70.1 67.0 11.0 8.0 3.8 2031.1670 MAR 72.8 70.5 67.1 11.2 8.2 3.8 2031.2503 APR 72.8 70.9 67.2 11.4 8.3 3.5 2031.3337 MAY 72.9 71.3 67.4 11.6 8.5 3.4 2031.4170 JUN 74.0 71.9 67.5 11.8 8.6 3.4 2031.5003 JUL 75.5 72.6 67.7 12.0 8.8 3.3 2031.5837 AUG 76.0 73.4 67.8 12.4 9.1 3.3 2031.6670 SEP 76.9 74.2 68.0 12.7 9.4 3.4 2031.7503 OCT 78.2 75.2 68.1 13.2 9.9 3.7 2031.8337 NOV 80.0 76.4 68.4 13.8 10.3 4.2 2031.9170 DEC 82.5 77.8 68.5 14.6 10.6 4.5 2032.0003 JAN 85.7 79.4 68.5 15.7 10.9 4.7 2032.0837 FEB 88.4 81.1 68.5 16.1 11.1 4.8 2032.1670 MAR 91.6 83.1 68.5 16.3 11.3 5.0 2032.2503 APR 94.6 85.2 68.4 16.9 11.4 5.1 2032.3337 MAY 97.2 87.5 68.6 18.0 11.6 5.3 2032.4170 JUN 99.1 89.9 68.7 18.9 11.9 5.4 2032.5003 JUL 103.2 92.5 69.0 19.1 12.1 5.6 2032.5837 AUG 108.1 95.3 69.3 19.2 12.3 5.8 2032.6670 SEP 112.2 98.1 69.4 19.0 12.6 6.0 2032.7503 OCT 116.5 100.9 69.6 18.6 12.7 6.1 2032.8337 NOV 120.0 103.7 70.1 18.5 12.7 6.1 2032.9170 DEC 122.7 106.7 70.8 18.9 12.8 6.1 2033.0003 JAN 125.5 109.8 71.0 18.8 12.9 6.3 2033.0837 FEB 129.4 113.0 71.4 17.8 13.0 6.5 2033.1670 MAR 133.2 116.2 71.7 17.9 13.2 6.7 2033.2503 APR 137.5 119.3 72.3 18.4 13.4 7.1 2033.3337 MAY 143.0 122.6 73.1 19.1 13.7 7.0 2033.4170 JUN 148.7 125.6 73.5 19.6 14.2 7.0 2033.5003 JUL 153.5 128.1 74.3 20.3 14.5 7.1 2033.5837 AUG 157.2 130.2 74.9 20.3 14.5 7.2 2033.6670 SEP 163.0 132.5 75.3 20.3 14.6 7.7 2033.7503 OCT 169.0 135.1 75.8 20.5 14.7 8.1 2033.8337 NOV 173.9 137.6 76.2 20.8 14.8 8.0 2033.9170 DEC 179.8 139.9 76.5 21.2 14.8 8.0 2034.0003 JAN 181.7 141.9 76.5 21.3 14.6 8.4 2034.0837 FEB 184.2 143.7 76.5 21.4 14.6 8.6 2034.1670 MAR 185.0 145.3 76.8 21.6 14.6 8.4 2034.2503 APR 184.8 146.8 77.3 22.0 14.5 8.4 2034.3337 MAY 184.0 147.9 77.8 22.7 14.4 8.6 2034.4170 JUN 183.8 148.7 78.5 22.4 14.1 8.6 2034.5003 JUL 185.2 149.3 79.8 21.3 13.8 8.5 2034.5837 AUG 186.7 149.6 80.6 20.6 13.7 8.3 2034.6670 SEP 187.4 149.9 81.6 20.1 13.6 8.0 2034.7503 OCT 187.1 150.2 83.1 19.7 13.5 7.6 2034.8337 NOV 186.0 150.3 84.6 19.6 13.5 7.5 2034.9170 DEC 186.2 150.3 86.2 19.3 13.5 7.8 2035.0003 JAN 184.1 149.6 87.0 19.1 13.7 7.7 2035.0837 FEB 179.8 148.5 88.2 18.9 13.9 7.6 2035.1670 MAR 176.9 147.7 89.8 18.9 14.0 7.5 2035.2503 APR 178.6 147.5 90.9 19.5 13.9 7.2 2035.3337 MAY 178.2 147.8 93.0 20.4 14.0 7.1 2035.4170 JUN 175.8 148.2 94.3 22.0 14.4 7.1 2035.5003 JUL 173.7 148.2 95.7 23.4 14.7 7.1 2035.5837 AUG 172.3 148.0 96.0 24.0 14.9 7.3 2035.6670 SEP 171.0 147.6 95.6 25.1 15.1 7.3 2035.7503 OCT 169.2 147.2 95.5 25.7 15.3 7.0 2035.8337 NOV 165.4 147.0 97.0 24.9 15.3 7.1 2035.9170 DEC 162.4 146.6 97.8 24.8 15.3 6.7 2036.0003 JAN 159.9 145.8 97.3 24.0 15.3 6.3 2036.0837 FEB 157.8 144.6 96.5 22.2 15.3 6.1 2036.1670 MAR 155.7 143.1 96.4 22.5 15.5 6.3 2036.2503 APR 155.3 141.4 96.9 23.2 15.7 6.5 2036.3337 MAY 155.2 140.0 96.4 23.2 15.7 6.7 2036.4170 JUN 153.7 138.7 95.7 22.7 15.7 7.1 2036.5003 JUL 150.5 137.2 96.3 22.0 15.6 7.6 2036.5837 AUG 146.7 135.5 97.2 21.9 15.7 7.7 2036.6670 SEP 143.8 133.5 96.3 22.7 15.9 8.1 2036.7503 OCT 140.4 131.8 94.6 23.6 16.2 8.7 2036.8337 NOV 137.4 130.4 93.8 23.8 16.4 8.9 2036.9170 DEC 136.7 129.2 93.6 23.8 16.6 9.3 2037.0003 JAN 136.0 127.5 91.8 23.8 16.6 9.7 2037.0837 FEB 134.8 125.7 88.5 23.4 16.6 10.1 2037.1670 MAR 133.8 124.4 88.0 22.5 16.5 10.5 2037.2503 APR 134.1 123.3 88.7 22.7 16.4 10.7 2037.3337 MAY 132.8 121.9 87.3 22.9 16.5 11.5 2037.4170 JUN 130.7 120.3 86.3 23.0 16.6 11.7 2037.5003 JUL 129.7 118.5 85.7 22.4 16.7 11.9 2037.5837 AUG 129.1 116.7 84.9 21.5 16.5 11.9 2037.6670 SEP 126.6 115.0 83.7 21.2 16.3 11.7 2037.7503 OCT 125.2 113.1 82.7 21.7 16.1 11.4 2037.8337 NOV 124.7 111.2 82.3 21.7 16.1 11.5 2037.9170 DEC 123.6 109.6 82.2 22.1 16.1 11.4 2038.0003 JAN 122.1 108.0 82.0 22.5 16.2 11.2 2038.0837 FEB 120.1 106.4 81.0 22.3 16.2 11.0 2038.1670 MAR 118.3 104.8 80.6 22.3 16.0 10.8 2038.2503 APR 116.2 103.4 80.6 22.7 15.8 10.7 2038.3337 MAY 114.3 101.8 80.0 22.9 15.5 10.6 2038.4170 JUN 111.1 100.2 79.1 23.4 15.3 10.3 2038.5003 JUL 109.5 98.7 77.7 24.0 15.0 10.1 2038.5837 AUG 107.9 97.5 75.6 24.7 14.9 10.1 2038.6670 SEP 106.4 96.3 74.6 25.3 14.8 10.1 2038.7503 OCT 104.4 95.2 74.1 25.4 14.8 10.5 2038.8337 NOV 103.0 94.3 73.8 25.3 14.7 10.4 2038.9170 DEC 102.0 93.3 73.5 24.8 14.5 10.2 2039.0003 JAN 100.5 92.1 73.1 23.9 14.3 10.0 2039.0837 FEB 98.9 91.0 72.7 23.0 14.1 9.4 2039.1670 MAR 98.2 90.0 72.0 22.5 14.2 8.8 2039.2503 APR 97.9 89.0 71.4 22.1 14.2 8.1 2039.3337 MAY 97.5 87.8 71.1 21.8 14.3 7.5 2039.4170 JUN 97.0 86.8 70.8 21.4 14.5 7.4 2039.5003 JUL 95.7 85.9 70.6 20.8 14.4 7.7 2039.5837 AUG 94.8 85.1 70.6 20.0 14.3 8.1 2039.6670 SEP 93.0 84.1 70.4 20.0 14.1 8.5 2039.7503 OCT 90.8 83.0 69.9 20.2 13.9 8.5 2039.8337 NOV 89.4 82.0 69.6 19.8 13.7 8.5 2039.9170 DEC 88.2 81.3 69.5 19.4 13.6 8.4 2040.0003 JAN 86.7 80.6 69.5 18.9 13.6 8.4 2040.0837 FEB 85.9 80.0 69.3 18.2 13.6 8.1 2040.1670 MAR 85.2 79.2 69.2 17.3 13.5 7.7 2040.2503 APR 83.9 78.5 68.8 17.3 13.3 7.1 2040.3337 MAY 82.8 77.8 68.6 17.4 13.2 6.8 2040.4170 JUN 81.8 77.2 68.4 17.5 13.1 6.6 2040.5003 JUL 81.2 76.6 68.4 17.5 12.9 6.5 2040.5837 AUG 80.7 76.1 68.5 17.7 12.9 6.6 2040.6670 SEP 80.5 75.6 68.5 18.0 12.7 6.5 2040.7503 OCT 79.2 75.1 68.5 17.9 12.6 6.4 2040.8337 NOV 77.9 74.6 68.4 17.6 12.3 6.4 2040.9170 DEC 77.2 73.9 68.3 17.3 12.0 6.2 2041.0003 JAN 76.7 73.2 68.0 16.3 11.7 6.1 2041.0837 FEB 75.8 72.6 67.8 14.9 11.2 6.0 2041.1670 MAR 75.3 72.1 67.7 13.8 10.9 6.1 2041.2503 APR 74.4 71.8 67.6 13.9 10.5 6.2 2041.3337 MAY 73.3 71.5 67.5 13.6 10.2 6.2 2041.4170 JUN 73.2 71.1 67.3 13.2 9.8 6.0 2041.5003 JUL 72.4 70.8 67.1 12.9 9.5 5.9 2041.5837 AUG 71.7 70.5 67.1 12.6 9.3 5.8 2041.6670 SEP 71.6 70.2 67.0 11.9 9.1 5.7 2041.7503 OCT 71.8 70.0 67.0 11.4 8.9 5.2