TABLE 3 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 95.0% 50% 5.0% 95.0% 50% 5.0% 2020.6670 SEP 76.4 75.3 74.6 5.8 5.5 5.3 2020.7503 OCT 79.1 76.4 74.8 6.8 5.7 5.2 2020.8337 NOV 82.1 77.8 75.9 7.6 6.0 5.1 2020.9170 DEC 84.9 79.4 76.9 8.0 6.2 5.0 2021.0003 JAN 87.3 81.2 78.0 8.2 6.2 4.7 2021.0837 FEB 90.6 83.2 78.8 8.8 6.2 4.5 2021.1670 MAR 94.6 85.4 79.3 9.5 6.3 4.1 2021.2503 APR 98.7 87.9 79.8 10.3 6.4 3.7 2021.3337 MAY 103.7 90.6 81.2 11.5 6.7 3.6 2021.4170 JUN 109.7 93.3 83.0 12.4 7.0 3.7 2021.5003 JUL 115.0 96.2 83.3 12.7 7.2 3.7 2021.5837 AUG 120.3 99.3 83.9 12.7 7.4 3.7 2021.6670 SEP 125.0 102.3 85.4 12.1 7.3 3.7 2021.7503 OCT 129.6 105.3 87.1 11.5 7.2 3.8 2021.8337 NOV 135.5 108.3 88.8 10.9 7.1 4.0 2021.9170 DEC 142.2 111.6 90.2 10.5 7.2 4.0 2022.0003 JAN 149.0 115.1 91.3 10.5 7.3 4.3 2022.0837 FEB 156.5 118.7 92.5 10.5 7.6 5.1 2022.1670 MAR 164.8 122.1 93.6 10.8 7.9 5.5 2022.2503 APR 172.8 125.4 95.5 10.7 8.3 6.1 2022.3337 MAY 178.4 128.9 97.8 10.7 8.4 6.2 2022.4170 JUN 182.4 132.2 99.9 11.3 8.7 5.7 2022.5003 JUL 186.0 134.6 101.1 12.1 8.9 5.5 2022.5837 AUG 189.4 136.9 101.5 12.2 9.1 5.3 2022.6670 SEP 194.2 139.4 102.1 12.8 9.4 5.5 2022.7503 OCT 200.6 142.1 103.6 13.7 9.9 5.8 2022.8337 NOV 205.7 144.7 104.6 14.4 10.1 5.5 2022.9170 DEC 209.3 147.0 105.2 14.8 10.2 5.3 2023.0003 JAN 213.8 149.0 106.5 15.3 10.5 5.0 2023.0837 FEB 218.5 150.8 109.4 15.8 10.7 4.7 2023.1670 MAR 221.3 152.3 112.2 16.1 10.8 4.7 2023.2503 APR 223.6 153.7 115.6 16.7 10.9 4.8 2023.3337 MAY 225.7 154.8 119.5 17.7 10.9 4.9 2023.4170 JUN 227.3 155.5 119.7 17.9 11.0 5.0 2023.5003 JUL 229.1 155.9 118.2 17.3 11.1 5.3 2023.5837 AUG 231.2 156.1 116.2 16.9 11.2 5.8 2023.6670 SEP 232.8 156.2 115.0 16.4 11.1 6.0 2023.7503 OCT 232.6 156.4 117.0 15.8 10.9 6.0 2023.8337 NOV 231.9 156.3 118.4 15.8 10.9 6.2 2023.9170 DEC 232.5 156.0 119.6 15.6 11.0 6.3 2024.0003 JAN 232.1 155.3 118.9 14.9 10.8 6.2 2024.0837 FEB 229.0 154.0 117.0 14.1 10.7 6.5 2024.1670 MAR 225.4 153.2 115.2 13.4 10.3 6.7 2024.2503 APR 221.8 152.9 112.7 13.0 9.8 6.1 2024.3337 MAY 219.7 153.2 110.5 13.2 9.6 5.8 2024.4170 JUN 219.2 153.5 109.0 14.1 9.7 5.5 2024.5003 JUL 218.3 153.5 107.7 15.0 9.7 5.2 2024.5837 AUG 216.4 153.1 104.3 15.5 9.8 5.4 2024.6670 SEP 214.5 152.7 101.0 16.2 9.8 5.2 2024.7503 OCT 213.6 152.3 97.6 16.3 9.8 5.2 2024.8337 NOV 213.0 152.1 96.3 15.8 9.9 6.0 2024.9170 DEC 213.4 151.7 95.5 15.5 9.8 6.2 2025.0003 JAN 212.3 150.8 94.2 14.5 9.6 6.3 2025.0837 FEB 209.4 149.6 93.0 14.2 9.6 6.3 2025.1670 MAR 206.6 147.9 91.3 14.2 9.9 7.1 2025.2503 APR 203.9 146.2 90.1 15.1 10.2 7.3 2025.3337 MAY 201.2 144.7 88.1 15.2 10.4 7.4 2025.4170 JUN 197.6 143.5 87.4 15.6 10.7 7.3 2025.5003 JUL 194.8 141.8 87.3 16.1 10.9 7.5 2025.5837 AUG 191.4 139.9 87.4 15.2 10.6 7.3 2025.6670 SEP 187.2 137.6 88.0 15.0 10.7 7.2 2025.7503 OCT 184.1 135.6 88.8 16.0 11.1 7.1 2025.8337 NOV 181.2 133.9 89.3 16.0 11.1 7.2 2025.9170 DEC 179.9 132.5 90.0 15.9 11.2 7.0 2026.0003 JAN 177.1 130.6 90.9 16.0 11.3 7.0 2026.0837 FEB 173.4 128.6 90.8 16.1 11.6 6.9 2026.1670 MAR 169.8 127.2 90.6 15.4 12.0 7.4 2026.2503 APR 166.6 126.0 90.4 15.4 12.3 7.9 2026.3337 MAY 164.6 124.5 90.1 16.1 12.7 8.8 2026.4170 JUN 162.8 122.8 89.6 16.6 13.0 8.7 2026.5003 JUL 159.2 120.8 89.5 16.5 13.4 9.2 2026.5837 AUG 153.7 118.8 88.9 16.8 13.5 9.3 2026.6670 SEP 148.4 117.0 87.8 18.0 13.5 9.4 2026.7503 OCT 144.8 115.0 86.5 18.6 13.4 9.5 2026.8337 NOV 142.3 113.1 85.5 19.0 13.6 9.8 2026.9170 DEC 140.2 111.4 85.3 19.2 13.8 9.8 2027.0003 JAN 137.5 109.9 84.7 19.5 13.9 10.2 2027.0837 FEB 134.2 108.2 84.2 19.2 13.8 9.7 2027.1670 MAR 131.4 106.5 84.1 19.3 13.7 9.5 2027.2503 APR 128.5 105.0 83.2 19.7 13.6 9.4 2027.3337 MAY 125.6 103.2 80.8 19.9 13.3 8.9 2027.4170 JUN 123.7 101.4 79.4 20.3 12.9 7.9 2027.5003 JUL 123.2 99.8 78.0 20.8 12.5 7.0 2027.5837 AUG 122.6 98.5 76.7 21.4 12.3 7.1 2027.6670 SEP 122.2 97.3 75.8 22.0 12.3 7.2 2027.7503 OCT 121.1 96.1 75.3 22.3 12.4 7.2 2027.8337 NOV 119.2 95.3 75.1 22.1 12.1 7.2 2027.9170 DEC 117.8 94.2 74.6 21.5 11.9 7.1 2028.0003 JAN 116.7 92.8 73.8 20.7 11.8 6.5 2028.0837 FEB 115.6 91.6 73.2 20.0 11.8 6.1 2028.1670 MAR 114.0 90.6 72.6 19.8 12.1 5.9 2028.2503 APR 110.6 89.4 72.3 19.5 12.2 5.3 2028.3337 MAY 106.9 88.1 72.1 19.4 12.4 4.9 2028.4170 JUN 103.9 87.0 71.7 19.2 12.7 5.0 2028.5003 JUL 102.0 86.2 71.3 18.7 12.8 5.5 2028.5837 AUG 100.8 85.2 71.1 18.7 12.7 5.9 2028.6670 SEP 98.5 84.2 70.9 18.9 12.5 6.2 2028.7503 OCT 97.0 83.1 70.4 19.0 12.3 6.2 2028.8337 NOV 95.2 82.2 70.3 18.8 12.3 6.4 2028.9170 DEC 94.3 81.5 70.3 18.6 12.4 6.7 2029.0003 JAN 93.7 80.8 70.3 18.3 12.7 7.2 2029.0837 FEB 92.9 80.2 70.4 17.7 13.0 7.5 2029.1670 MAR 91.1 79.5 70.3 16.9 13.0 7.6 2029.2503 APR 90.0 78.8 70.1 16.9 12.7 7.4 2029.3337 MAY 89.1 78.1 70.0 16.9 12.5 7.1 2029.4170 JUN 88.0 77.5 69.9 16.9 12.2 6.8 2029.5003 JUL 87.1 76.9 69.8 17.1 12.2 6.3 2029.5837 AUG 86.3 76.3 69.6 17.5 12.4 6.4 2029.6670 SEP 85.0 75.8 69.5 17.8 12.3 6.6 2029.7503 OCT 83.5 75.3 69.4 17.8 12.2 6.5 2029.8337 NOV 81.5 74.8 69.3 17.5 12.0 6.5 2029.9170 DEC 79.5 74.1 69.1 17.2 11.7 6.3 2030.0003 JAN 78.5 73.4 68.7 16.1 11.2 6.3 2030.0837 FEB 77.7 72.7 68.4 14.5 10.6 6.4 2030.1670 MAR 77.3 72.2 68.1 13.2 10.1 6.2 2030.2503 APR 77.1 71.9 68.0 13.3 9.7 6.0 2030.3337 MAY 76.9 71.6 67.9 12.9 9.2 5.8 2030.4170 JUN 76.7 71.3 67.8 12.6 9.0 5.7 2030.5003 JUL 75.9 71.0 67.8 12.4 8.8 5.7 2030.5837 AUG 74.9 70.7 67.7 12.1 8.7 5.3 2030.6670 SEP 73.8 70.4 67.7 11.4 8.5 4.8 2030.7503 OCT 73.5 70.2 67.4 11.0 8.3 4.4 2030.8337 NOV 73.0 70.0 67.3 10.8 8.1 4.1 2030.9170 DEC 73.1 70.0 67.3 10.8 8.1 4.1 2031.0003 JAN 73.2 70.1 67.2 11.0 8.2 4.0 2031.0837 FEB 73.9 70.4 67.3 11.4 8.4 4.0 2031.1670 MAR 74.8 70.8 67.4 11.5 8.6 3.9 2031.2503 APR 75.5 71.1 67.4 11.7 8.7 3.7 2031.3337 MAY 76.6 71.5 67.6 11.9 8.8 3.5 2031.4170 JUN 78.3 72.1 67.7 12.0 8.9 3.5 2031.5003 JUL 79.7 72.7 67.8 12.1 9.0 3.4 2031.5837 AUG 81.1 73.5 67.9 12.5 9.3 3.4 2031.6670 SEP 83.3 74.3 68.0 12.8 9.6 3.4 2031.7503 OCT 86.2 75.3 68.1 13.3 10.0 3.8 2031.8337 NOV 90.9 76.4 68.4 13.8 10.3 4.2 2031.9170 DEC 95.1 77.8 68.5 14.6 10.6 4.5 2032.0003 JAN 98.5 79.4 68.5 15.7 10.9 4.7 2032.0837 FEB 103.6 81.1 68.5 16.1 11.1 4.8 2032.1670 MAR 109.2 83.1 68.5 16.3 11.3 5.0 2032.2503 APR 115.2 85.2 68.4 16.9 11.4 5.1 2032.3337 MAY 122.0 87.5 68.6 18.0 11.6 5.3 2032.4170 JUN 130.1 89.9 68.7 18.9 11.9 5.4 2032.5003 JUL 136.6 92.5 69.0 19.1 12.1 5.6 2032.5837 AUG 141.4 95.3 69.3 19.2 12.3 5.8 2032.6670 SEP 145.9 98.1 69.4 19.0 12.6 6.0 2032.7503 OCT 150.4 100.9 69.6 18.6 12.7 6.1 2032.8337 NOV 155.4 103.7 70.1 18.5 12.7 6.1 2032.9170 DEC 160.9 106.7 70.8 18.9 12.8 6.1 2033.0003 JAN 166.3 109.8 71.0 18.8 12.9 6.3 2033.0837 FEB 171.1 113.0 71.4 17.8 13.0 6.5 2033.1670 MAR 177.2 116.2 71.7 17.9 13.2 6.7 2033.2503 APR 184.3 119.3 72.3 18.4 13.4 7.1 2033.3337 MAY 189.1 122.6 73.1 19.1 13.7 7.0 2033.4170 JUN 192.1 125.6 73.5 19.6 14.2 7.0 2033.5003 JUL 195.2 128.1 74.3 20.3 14.5 7.1 2033.5837 AUG 198.1 130.2 74.9 20.3 14.5 7.2 2033.6670 SEP 203.0 132.5 75.3 20.3 14.6 7.7 2033.7503 OCT 208.8 135.1 75.8 20.5 14.7 8.1 2033.8337 NOV 213.0 137.6 76.2 20.8 14.8 8.0 2033.9170 DEC 215.9 139.9 76.5 21.2 14.8 8.0 2034.0003 JAN 219.7 141.9 76.5 21.3 14.6 8.4 2034.0837 FEB 223.3 143.7 76.5 21.4 14.6 8.6 2034.1670 MAR 224.8 145.3 76.8 21.6 14.6 8.4 2034.2503 APR 225.6 146.8 77.3 22.0 14.5 8.4 2034.3337 MAY 228.0 147.9 77.8 22.7 14.4 8.6 2034.4170 JUN 230.3 148.7 78.5 22.4 14.1 8.6 2034.5003 JUL 233.0 149.3 79.8 21.3 13.8 8.5 2034.5837 AUG 235.9 149.6 80.6 20.6 13.7 8.3 2034.6670 SEP 237.0 149.9 81.6 20.1 13.6 8.0 2034.7503 OCT 234.9 150.2 83.1 19.7 13.5 7.6 2034.8337 NOV 232.6 150.3 84.6 19.6 13.5 7.5 2034.9170 DEC 233.6 150.3 86.2 19.3 13.5 7.8 2035.0003 JAN 234.0 149.6 87.0 19.1 13.7 7.7 2035.0837 FEB 231.8 148.5 88.2 18.9 13.9 7.6 2035.1670 MAR 228.8 147.7 89.8 18.9 14.0 7.5 2035.2503 APR 225.5 147.5 90.9 19.5 13.9 7.2 2035.3337 MAY 224.0 147.8 93.0 20.4 14.0 7.1 2035.4170 JUN 225.0 148.2 94.3 22.0 14.4 7.1 2035.5003 JUL 224.9 148.2 95.7 23.4 14.7 7.1 2035.5837 AUG 223.7 148.0 96.0 24.0 14.9 7.3 2035.6670 SEP 222.8 147.6 95.6 25.1 15.1 7.3 2035.7503 OCT 222.5 147.2 95.5 25.7 15.3 7.0 2035.8337 NOV 222.1 147.0 97.0 24.9 15.3 7.1 2035.9170 DEC 221.5 146.6 97.8 24.8 15.3 6.7 2036.0003 JAN 220.9 145.8 97.3 24.0 15.3 6.3 2036.0837 FEB 218.8 144.6 96.5 22.2 15.3 6.1 2036.1670 MAR 215.7 143.1 96.4 22.5 15.5 6.3 2036.2503 APR 213.2 141.4 96.9 23.2 15.7 6.5 2036.3337 MAY 210.6 140.0 96.4 23.2 15.7 6.7 2036.4170 JUN 206.4 138.7 95.7 22.7 15.7 7.1 2036.5003 JUL 203.6 137.2 96.3 22.0 15.6 7.6 2036.5837 AUG 202.2 135.5 97.2 21.9 15.7 7.7 2036.6670 SEP 198.5 133.5 96.3 22.7 15.9 8.1 2036.7503 OCT 194.7 131.8 94.6 23.6 16.2 8.7 2036.8337 NOV 192.8 130.4 93.8 23.8 16.4 8.9 2036.9170 DEC 191.1 129.2 93.6 23.8 16.6 9.3 2037.0003 JAN 187.6 127.5 91.8 23.8 16.6 9.7 2037.0837 FEB 183.5 125.7 88.5 23.4 16.6 10.1 2037.1670 MAR 179.5 124.4 88.0 22.5 16.5 10.5 2037.2503 APR 175.8 123.3 88.7 22.7 16.4 10.7 2037.3337 MAY 173.5 121.9 87.3 22.9 16.5 11.5 2037.4170 JUN 171.4 120.3 86.3 23.0 16.6 11.7 2037.5003 JUL 167.1 118.5 85.7 22.4 16.7 11.9 2037.5837 AUG 160.7 116.7 84.9 21.5 16.5 11.9 2037.6670 SEP 155.0 115.0 83.7 21.2 16.3 11.7 2037.7503 OCT 151.3 113.1 82.7 21.7 16.1 11.4 2037.8337 NOV 148.8 111.2 82.3 21.7 16.1 11.5 2037.9170 DEC 146.2 109.6 82.2 22.1 16.1 11.4 2038.0003 JAN 143.2 108.0 82.0 22.5 16.2 11.2 2038.0837 FEB 139.6 106.4 81.0 22.3 16.2 11.0 2038.1670 MAR 135.9 104.8 80.6 22.3 16.0 10.8 2038.2503 APR 132.4 103.4 80.6 22.7 15.8 10.7 2038.3337 MAY 128.4 101.8 80.0 22.9 15.5 10.6 2038.4170 JUN 123.3 100.2 79.1 23.4 15.3 10.3 2038.5003 JUL 119.4 98.7 77.7 24.0 15.0 10.1 2038.5837 AUG 118.5 97.5 75.6 24.7 14.9 10.1 2038.6670 SEP 118.7 96.3 74.6 25.3 14.8 10.1 2038.7503 OCT 119.2 95.2 74.1 25.4 14.8 10.5 2038.8337 NOV 119.5 94.3 73.8 25.3 14.7 10.4 2038.9170 DEC 118.8 93.3 73.5 24.8 14.5 10.2 2039.0003 JAN 117.3 92.1 73.1 23.9 14.3 10.0 2039.0837 FEB 115.7 91.0 72.7 23.0 14.1 9.4 2039.1670 MAR 113.5 90.0 72.0 22.5 14.2 8.8 2039.2503 APR 110.0 89.0 71.4 22.1 14.2 8.1 2039.3337 MAY 105.8 87.8 71.1 21.8 14.3 7.5 2039.4170 JUN 103.2 86.8 70.8 21.4 14.5 7.4 2039.5003 JUL 101.6 85.9 70.6 20.8 14.4 7.7 2039.5837 AUG 100.1 85.1 70.6 20.0 14.3 8.1 2039.6670 SEP 98.1 84.1 70.4 20.0 14.1 8.5 2039.7503 OCT 96.5 83.0 69.9 20.2 13.9 8.5 2039.8337 NOV 94.6 82.0 69.6 19.8 13.7 8.5 2039.9170 DEC 93.5 81.3 69.5 19.4 13.6 8.4 2040.0003 JAN 93.1 80.6 69.5 18.9 13.6 8.4 2040.0837 FEB 92.3 80.0 69.3 18.2 13.6 8.1 2040.1670 MAR 91.2 79.2 69.2 17.3 13.5 7.7 2040.2503 APR 90.3 78.5 68.8 17.3 13.3 7.1 2040.3337 MAY 89.5 77.8 68.6 17.4 13.2 6.8 2040.4170 JUN 88.4 77.2 68.4 17.5 13.1 6.6 2040.5003 JUL 87.4 76.6 68.4 17.5 12.9 6.5 2040.5837 AUG 86.6 76.1 68.5 17.7 12.9 6.6 2040.6670 SEP 85.2 75.6 68.5 18.0 12.7 6.5 2040.7503 OCT 83.9 75.1 68.5 17.9 12.6 6.4 2040.8337 NOV 82.0 74.6 68.4 17.6 12.3 6.4 2040.9170 DEC 79.9 73.9 68.3 17.3 12.0 6.2 2041.0003 JAN 78.4 73.2 68.0 16.3 11.7 6.1 2041.0837 FEB 77.5 72.6 67.8 14.9 11.2 6.0 2041.1670 MAR 77.0 72.1 67.7 13.8 10.9 6.1 2041.2503 APR 76.9 71.8 67.6 13.9 10.5 6.2 2041.3337 MAY 76.6 71.5 67.5 13.6 10.2 6.2 2041.4170 JUN 76.5 71.1 67.3 13.2 9.8 6.0 2041.5003 JUL 76.1 70.8 67.1 12.9 9.5 5.9 2041.5837 AUG 75.1 70.5 67.1 12.6 9.3 5.8 2041.6670 SEP 74.2 70.2 67.0 11.9 9.1 5.7 2041.7503 OCT 74.0 70.0 67.0 11.4 8.9 5.2