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% 2023.8337 NOV 160.1 158.8 153.9 9.8 9.3 8.9 2023.9170 DEC 160.7 158.5 150.4 10.0 9.4 8.8 2024.0003 JAN 160.4 157.7 148.5 10.3 9.4 8.3 2024.0837 FEB 159.7 156.3 146.6 11.9 9.6 8.2 2024.1670 MAR 160.0 155.3 144.8 12.8 9.7 8.0 2024.2503 APR 159.6 154.9 141.6 13.5 9.6 7.6 2024.3337 MAY 161.1 155.1 139.5 14.4 9.6 7.6 2024.4170 JUN 162.7 155.3 138.1 15.8 9.8 7.6 2024.5003 JUL 163.9 155.2 136.3 16.9 10.0 7.8 2024.5837 AUG 163.5 154.8 135.5 17.6 10.2 8.2 2024.6670 SEP 163.5 154.4 132.1 18.6 10.3 8.1 2024.7503 OCT 164.0 153.9 128.5 18.8 10.3 7.6 2024.8337 NOV 163.1 153.6 126.6 18.2 10.4 7.3 2024.9170 DEC 162.5 153.2 125.0 18.3 10.5 7.1 2025.0003 JAN 162.5 152.3 123.2 17.8 10.7 7.3 2025.0837 FEB 160.7 151.0 121.6 16.4 10.8 7.2 2025.1670 MAR 159.6 149.2 119.1 16.3 10.9 7.3 2025.2503 APR 157.0 147.4 117.5 16.0 11.1 7.6 2025.3337 MAY 155.1 145.8 115.5 16.2 11.3 8.1 2025.4170 JUN 152.6 144.5 114.4 16.9 11.7 8.6 2025.5003 JUL 150.5 142.8 113.4 17.8 12.0 8.9 2025.5837 AUG 150.0 140.8 112.5 18.7 12.2 8.9 2025.6670 SEP 148.6 138.6 111.3 19.5 12.4 8.9 2025.7503 OCT 146.5 136.5 110.3 19.8 12.7 8.9 2025.8337 NOV 144.6 134.9 109.3 19.9 12.7 8.9 2025.9170 DEC 143.5 133.4 108.1 20.6 13.0 8.8 2026.0003 JAN 141.5 131.6 105.3 21.2 13.1 8.7 2026.0837 FEB 140.0 129.6 102.1 21.3 13.2 8.5 2026.1670 MAR 139.4 128.2 100.6 21.4 13.6 8.9 2026.2503 APR 139.1 127.0 100.0 21.8 14.0 9.4 2026.3337 MAY 137.4 125.5 98.8 22.2 14.4 10.3 2026.4170 JUN 133.9 123.8 97.8 22.3 14.6 10.8 2026.5003 JUL 130.2 121.8 96.6 21.7 14.6 10.9 2026.5837 AUG 126.8 119.7 95.0 20.8 14.7 11.2 2026.6670 SEP 123.3 117.8 93.2 20.1 14.8 11.5 2026.7503 OCT 121.3 115.8 91.5 20.8 15.0 11.8 2026.8337 NOV 120.4 113.8 90.0 21.1 15.3 11.8 2026.9170 DEC 119.2 112.1 88.7 21.3 15.6 11.6 2027.0003 JAN 116.9 110.5 88.1 21.9 15.7 11.3 2027.0837 FEB 114.5 108.7 87.1 21.7 15.7 11.1 2027.1670 MAR 113.9 107.0 86.0 21.6 15.5 10.9 2027.2503 APR 112.6 105.4 84.2 21.8 15.2 11.0 2027.3337 MAY 111.0 103.7 81.6 22.1 15.0 10.8 2027.4170 JUN 109.4 101.9 79.9 22.8 14.9 10.3 2027.5003 JUL 108.1 100.3 79.0 23.4 14.6 9.6 2027.5837 AUG 107.8 99.0 77.8 23.9 14.3 9.3 2027.6670 SEP 106.6 97.8 76.9 24.2 14.1 9.0 2027.7503 OCT 104.9 96.6 76.4 24.5 14.1 9.0 2027.8337 NOV 103.4 95.8 76.3 24.4 13.9 9.2 2027.9170 DEC 101.9 94.7 75.8 23.9 13.8 9.5 2028.0003 JAN 100.7 93.5 75.0 23.1 13.8 9.5 2028.0837 FEB 99.0 92.3 74.2 22.5 13.8 9.1 2028.1670 MAR 97.5 91.2 73.7 22.3 14.0 8.7 2028.2503 APR 97.0 90.1 73.3 22.0 14.1 8.0 2028.3337 MAY 97.3 88.8 73.1 21.8 14.3 7.4 2028.4170 JUN 95.5 87.7 73.1 21.2 14.3 7.3 2028.5003 JUL 94.7 86.8 72.9 20.6 14.3 7.6 2028.5837 AUG 93.3 85.9 72.6 19.8 14.1 8.0 2028.6670 SEP 91.4 84.8 72.6 20.0 13.9 8.3 2028.7503 OCT 89.7 83.7 72.4 20.0 13.6 8.2 2028.8337 NOV 88.5 82.6 71.7 19.7 13.4 8.2 2028.9170 DEC 87.4 81.9 71.8 19.2 13.3 8.1 2029.0003 JAN 86.5 81.2 72.1 18.7 13.2 8.0 2029.0837 FEB 85.5 80.5 71.9 17.8 12.9 7.9 2029.1670 MAR 84.8 79.7 71.7 16.8 12.6 7.6 2029.2503 APR 83.4 79.0 71.5 16.8 12.1 7.2 2029.3337 MAY 82.0 78.3 71.4 16.9 11.8 7.1 2029.4170 JUN 80.6 77.7 71.2 17.0 11.8 6.9 2029.5003 JUL 79.1 77.1 71.1 17.0 11.8 6.4 2029.5837 AUG 79.0 76.6 71.0 17.2 11.7 6.1 2029.6670 SEP 79.0 76.0 70.8 16.7 11.7 6.4 2029.7503 OCT 78.5 75.5 70.7 16.7 11.6 6.7 2029.8337 NOV 78.0 75.0 70.6 16.5 11.5 6.7 2029.9170 DEC 77.2 74.3 70.2 16.3 11.2 6.5 2030.0003 JAN 76.6 73.6 69.8 15.5 11.0 6.3 2030.0837 FEB 75.7 72.9 69.5 14.3 10.8 6.2 2030.1670 MAR 74.5 72.4 69.2 13.7 10.6 6.2 2030.2503 APR 74.0 72.1 68.9 13.9 10.4 6.2 2030.3337 MAY 73.1 71.7 68.6 13.6 10.2 6.2 2030.4170 JUN 72.4 71.4 68.3 13.2 9.8 6.0 2030.5003 JUL 72.2 71.0 68.2 12.8 9.4 5.9 2030.5837 AUG 71.4 70.7 68.1 12.5 9.2 5.9 2030.6670 SEP 70.8 70.5 67.8 11.8 8.9 5.5 2030.7503 OCT 70.8 70.3 67.8 11.3 8.7 5.0 2030.8337 NOV 70.9 70.1 67.8 11.0 8.4 4.7 2030.9170 DEC 71.0 70.0 67.7 11.1 8.5 4.7 2031.0003 JAN 71.2 70.1 67.7 11.3 8.5 4.5 2031.0837 FEB 71.8 70.4 67.7 11.6 8.7 4.5 2031.1670 MAR 72.6 70.8 67.7 11.7 8.8 4.4 2031.2503 APR 72.6 71.1 67.7 11.9 8.9 4.1 2031.3337 MAY 72.8 71.5 67.8 12.0 9.0 3.9 2031.4170 JUN 73.9 72.1 67.9 12.1 9.1 3.7 2031.5003 JUL 75.4 72.8 68.0 12.2 9.2 3.6 2031.5837 AUG 76.0 73.5 68.0 12.6 9.3 3.5 2031.6670 SEP 76.9 74.3 68.1 12.9 9.6 3.5 2031.7503 OCT 78.2 75.3 68.2 13.3 10.0 3.8 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