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% 2020.2503 APR 70.7 70.4 69.8 5.4 5.2 5.0 2020.3337 MAY 71.1 70.8 69.6 5.9 5.3 4.8 2020.4170 JUN 71.7 71.3 69.9 6.4 5.3 4.5 2020.5003 JUL 72.5 71.9 69.9 6.9 5.3 4.2 2020.5837 AUG 73.8 72.6 70.1 7.4 5.3 4.0 2020.6670 SEP 75.0 73.4 69.9 7.6 5.3 3.9 2020.7503 OCT 76.1 74.2 69.6 7.8 5.5 3.9 2020.8337 NOV 77.1 75.3 69.9 8.0 5.7 4.0 2020.9170 DEC 78.6 76.5 70.5 8.1 5.8 4.3 2021.0003 JAN 80.1 77.9 70.7 8.1 5.7 4.0 2021.0837 FEB 82.3 79.4 70.6 8.0 5.6 3.7 2021.1670 MAR 85.3 81.2 70.8 8.1 5.6 3.5 2021.2503 APR 88.3 83.0 70.6 8.6 5.6 3.0 2021.3337 MAY 90.8 85.1 70.3 9.6 5.7 2.7 2021.4170 JUN 93.1 87.2 70.4 10.4 5.9 2.7 2021.5003 JUL 95.4 89.5 71.0 10.6 6.0 2.6 2021.5837 AUG 98.8 92.1 72.1 10.5 6.1 2.6 2021.6670 SEP 102.7 94.6 72.7 10.0 6.1 2.6 2021.7503 OCT 105.5 97.2 73.0 9.4 6.1 2.8 2021.8337 NOV 108.5 99.8 74.0 8.8 6.0 3.0 2021.9170 DEC 112.5 102.6 75.4 8.3 6.1 3.1 2022.0003 JAN 115.6 105.5 75.9 8.7 6.3 3.4 2022.0837 FEB 118.9 108.3 76.6 9.8 6.7 4.4 2022.1670 MAR 122.8 111.2 76.8 10.2 7.2 5.0 2022.2503 APR 124.3 114.1 78.7 10.2 7.6 5.2 2022.3337 MAY 129.3 117.2 81.0 10.3 7.8 5.4 2022.4170 JUN 134.5 120.1 82.7 10.9 8.1 4.9 2022.5003 JUL 138.4 122.5 83.7 11.6 8.2 4.5 2022.5837 AUG 140.5 124.6 83.7 11.7 8.3 4.3 2022.6670 SEP 144.9 126.7 83.5 12.3 8.7 4.5 2022.7503 OCT 149.3 129.1 84.3 13.2 9.2 4.8 2022.8337 NOV 152.2 131.5 83.8 13.9 9.3 4.4 2022.9170 DEC 153.8 133.7 84.2 14.1 9.3 4.0 2023.0003 JAN 155.5 135.6 85.0 14.1 9.7 3.7 2023.0837 FEB 155.2 137.4 88.3 13.8 10.0 3.6 2023.1670 MAR 153.5 139.0 92.2 13.7 10.0 3.5 2023.2503 APR 154.5 140.5 93.5 14.1 10.0 3.5 2023.3337 MAY 157.5 141.6 94.6 14.9 9.9 3.2 2023.4170 JUN 161.9 142.3 93.8 15.1 9.8 3.2 2023.5003 JUL 166.0 143.0 92.6 14.7 10.0 3.7 2023.5837 AUG 168.5 143.4 92.4 14.6 10.2 4.2 2023.6670 SEP 170.0 143.6 93.0 14.1 10.2 4.6 2023.7503 OCT 166.5 144.0 94.0 13.5 10.0 4.6 2023.8337 NOV 163.5 144.2 95.7 13.5 10.0 4.8 2023.9170 DEC 161.7 144.3 97.6 13.4 10.1 4.9 2024.0003 JAN 163.9 143.8 98.7 12.9 9.8 4.6 2024.0837 FEB 164.7 142.7 99.5 12.6 9.7 4.9 2024.1670 MAR 164.1 142.0 100.5 12.2 9.2 5.0 2024.2503 APR 164.0 141.9 101.7 12.1 8.7 4.9 2024.3337 MAY 163.7 142.2 103.0 12.3 8.6 4.7 2024.4170 JUN 161.7 142.6 104.3 13.3 8.6 4.4 2024.5003 JUL 160.5 142.6 105.7 14.2 8.6 4.3 2024.5837 AUG 162.4 142.5 105.9 14.7 8.7 4.6 2024.6670 SEP 162.6 142.2 103.7 15.4 8.7 4.6 2024.7503 OCT 161.2 141.8 100.7 15.5 8.6 4.4 2024.8337 NOV 159.7 141.7 99.2 15.0 8.8 4.7 2024.9170 DEC 159.8 141.5 98.0 15.0 8.9 4.7 2025.0003 JAN 160.2 140.7 96.9 14.1 8.8 5.6 2025.0837 FEB 157.2 139.6 95.2 12.7 8.8 5.7 2025.1670 MAR 154.2 138.2 93.3 12.8 9.1 5.8 2025.2503 APR 153.5 136.6 92.7 13.2 9.5 5.9 2025.3337 MAY 153.5 135.0 91.9 13.9 9.8 6.2 2025.4170 JUN 153.5 133.8 90.9 15.0 10.2 6.8 2025.5003 JUL 152.8 132.4 90.5 16.0 10.5 7.3 2025.5837 AUG 150.4 130.8 90.3 16.8 10.4 7.1 2025.6670 SEP 147.5 129.0 90.5 17.2 10.4 6.9 2025.7503 OCT 145.6 127.6 91.0 17.7 10.7 7.0 2025.8337 NOV 144.7 126.6 91.0 17.6 10.7 6.9 2025.9170 DEC 142.9 125.6 91.4 17.0 10.7 6.7 2026.0003 JAN 138.8 124.0 92.0 16.0 10.7 6.5 2026.0837 FEB 135.5 122.3 91.8 14.7 10.7 6.4 2026.1670 MAR 133.2 121.2 91.5 14.1 11.2 6.9 2026.2503 APR 132.0 120.2 90.9 14.2 11.6 7.4 2026.3337 MAY 129.1 118.9 89.4 14.9 11.9 8.2 2026.4170 JUN 127.2 117.4 88.6 15.0 12.0 7.8 2026.5003 JUL 127.0 115.7 87.9 14.6 12.2 8.0 2026.5837 AUG 126.2 114.2 87.2 15.6 12.3 8.5 2026.6670 SEP 124.9 112.6 86.2 16.9 12.4 8.8 2026.7503 OCT 123.4 110.7 84.9 17.8 12.5 9.8 2026.8337 NOV 120.3 108.8 83.8 18.2 12.9 9.2 2026.9170 DEC 117.1 107.0 83.5 18.1 13.1 9.0 2027.0003 JAN 114.6 105.5 83.4 18.5 13.3 8.7 2027.0837 FEB 112.8 103.9 82.9 18.5 13.4 8.3 2027.1670 MAR 110.6 102.4 82.6 18.6 13.3 8.2 2027.2503 APR 110.1 101.1 81.9 19.1 13.2 8.2 2027.3337 MAY 108.7 99.7 81.5 19.4 13.1 7.9 2027.4170 JUN 105.9 98.2 80.5 19.9 12.8 7.0 2027.5003 JUL 103.9 96.8 79.6 20.4 12.4 6.0 2027.5837 AUG 101.4 95.7 78.3 20.7 12.0 5.8 2027.6670 SEP 100.8 94.6 77.4 21.0 11.8 5.6 2027.7503 OCT 100.3 93.5 76.9 21.3 11.7 5.5 2027.8337 NOV 100.1 92.7 76.6 20.9 11.4 5.4 2027.9170 DEC 100.0 91.8 76.1 20.2 11.1 5.3 2028.0003 JAN 99.6 90.7 75.2 19.2 10.9 5.4 2028.0837 FEB 98.3 89.7 74.4 18.5 10.9 5.7 2028.1670 MAR 97.5 88.9 73.5 18.2 11.1 6.0 2028.2503 APR 97.6 88.0 73.1 17.9 11.2 5.5 2028.3337 MAY 97.2 86.9 72.9 17.7 11.4 5.0 2028.4170 JUN 95.6 85.9 72.6 17.5 11.6 5.0 2028.5003 JUL 93.5 85.1 72.3 17.7 11.8 5.5 2028.5837 AUG 92.0 84.3 72.2 18.1 11.8 6.1 2028.6670 SEP 90.2 83.5 71.9 18.4 11.7 6.4 2028.7503 OCT 88.3 82.4 71.6 18.5 11.5 6.4 2028.8337 NOV 86.6 81.4 71.3 18.3 11.6 6.6 2028.9170 DEC 86.8 80.7 71.1 18.1 11.7 6.8 2029.0003 JAN 85.8 80.1 71.0 17.8 12.1 7.1 2029.0837 FEB 83.9 79.4 71.0 17.2 12.3 7.3 2029.1670 MAR 82.3 78.6 70.8 16.4 12.2 7.2 2029.2503 APR 81.5 77.9 70.3 16.4 11.9 7.0 2029.3337 MAY 81.2 77.2 70.0 16.4 11.6 6.9 2029.4170 JUN 80.9 76.6 69.9 16.4 11.3 6.5 2029.5003 JUL 80.4 76.1 69.9 16.4 11.2 5.9 2029.5837 AUG 80.3 75.6 69.8 16.8 11.4 5.8 2029.6670 SEP 80.0 75.2 69.7 17.2 11.5 6.2 2029.7503 OCT 79.5 74.7 69.2 17.2 11.4 6.6 2029.8337 NOV 78.4 74.2 69.1 17.0 11.3 6.6 2029.9170 DEC 77.4 73.5 68.8 16.7 11.1 6.4 2030.0003 JAN 75.3 72.9 68.5 15.6 10.6 6.3 2030.0837 FEB 74.1 72.3 68.3 14.1 10.0 6.3 2030.1670 MAR 73.7 71.9 68.1 12.9 9.6 6.2 2030.2503 APR 73.9 71.6 68.1 13.0 9.2 6.1 2030.3337 MAY 73.5 71.2 67.9 12.7 8.9 5.9 2030.4170 JUN 72.9 70.9 67.8 12.3 8.6 5.8 2030.5003 JUL 72.3 70.6 67.7 12.1 8.5 5.7 2030.5837 AUG 72.1 70.3 67.4 11.8 8.3 5.3 2030.6670 SEP 71.5 70.0 67.2 11.1 7.9 4.7 2030.7503 OCT 71.4 69.8 66.9 10.5 7.7 4.2 2030.8337 NOV 71.2 69.6 67.0 10.3 7.5 3.9 2030.9170 DEC 71.3 69.6 67.0 10.4 7.6 3.9 2031.0003 JAN 71.5 69.8 67.0 10.7 7.7 3.8 2031.0837 FEB 72.1 70.1 67.1 11.0 8.0 3.9 2031.1670 MAR 72.8 70.5 67.2 11.2 8.2 3.8 2031.2503 APR 72.8 70.9 67.3 11.5 8.3 3.6 2031.3337 MAY 73.0 71.3 67.4 11.7 8.5 3.4 2031.4170 JUN 74.0 71.9 67.6 11.8 8.7 3.4 2031.5003 JUL 75.5 72.6 67.7 12.0 8.8 3.4 2031.5837 AUG 76.0 73.4 67.8 12.4 9.1 3.3 2031.6670 SEP 76.9 74.2 68.0 12.8 9.5 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