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% 2020.1670 MAR 70.8 70.2 69.6 5.6 5.4 5.2 2020.2503 APR 72.0 70.5 69.6 5.7 5.3 5.0 2020.3337 MAY 73.0 70.9 69.4 6.0 5.4 4.8 2020.4170 JUN 74.6 71.4 69.6 6.5 5.4 4.5 2020.5003 JUL 75.9 72.0 69.6 7.0 5.4 4.2 2020.5837 AUG 77.2 72.7 69.7 7.6 5.4 4.1 2020.6670 SEP 79.3 73.5 69.8 7.8 5.4 3.9 2020.7503 OCT 81.8 74.4 69.5 7.9 5.6 3.9 2020.8337 NOV 86.0 75.5 69.7 8.1 5.8 4.0 2020.9170 DEC 89.8 76.7 69.9 8.2 5.9 4.2 2021.0003 JAN 92.9 78.1 69.7 8.2 5.8 4.2 2021.0837 FEB 97.4 79.7 69.6 8.2 5.7 3.8 2021.1670 MAR 102.6 81.5 69.7 8.2 5.7 3.5 2021.2503 APR 107.8 83.4 69.2 8.4 5.6 3.0 2021.3337 MAY 114.2 85.5 68.7 9.3 5.7 2.7 2021.4170 JUN 121.5 87.7 68.7 10.1 5.9 2.7 2021.5003 JUL 127.3 90.0 69.2 10.2 6.0 2.6 2021.5837 AUG 131.4 92.6 70.1 10.1 6.1 2.6 2021.6670 SEP 135.1 95.2 70.6 9.6 6.1 2.6 2021.7503 OCT 139.0 97.8 70.7 9.1 6.1 2.8 2021.8337 NOV 143.4 100.5 71.5 8.5 6.1 3.0 2021.9170 DEC 149.7 103.3 72.8 8.1 6.1 3.1 2022.0003 JAN 156.3 106.2 73.4 8.5 6.4 3.5 2022.0837 FEB 162.9 109.1 74.4 9.7 6.7 4.5 2022.1670 MAR 170.7 112.0 75.8 10.1 7.2 5.0 2022.2503 APR 177.6 115.0 77.3 10.1 7.6 5.2 2022.3337 MAY 182.1 118.1 79.1 10.4 7.9 5.5 2022.4170 JUN 184.4 121.0 80.5 10.8 8.1 5.1 2022.5003 JUL 186.0 123.4 82.3 11.4 8.3 4.7 2022.5837 AUG 189.2 125.5 83.7 11.6 8.4 4.6 2022.6670 SEP 194.3 127.6 84.5 12.2 8.8 4.7 2022.7503 OCT 200.5 130.0 84.5 13.0 9.2 4.9 2022.8337 NOV 205.3 132.4 83.7 13.7 9.3 4.5 2022.9170 DEC 208.5 134.6 84.0 13.9 9.3 4.1 2023.0003 JAN 212.5 136.5 84.6 13.9 9.7 3.8 2023.0837 FEB 216.7 138.3 86.5 13.6 10.0 3.6 2023.1670 MAR 218.9 139.9 87.7 13.5 10.0 3.6 2023.2503 APR 220.1 141.3 89.3 13.8 9.9 3.5 2023.3337 MAY 222.1 142.4 90.3 14.6 9.8 3.2 2023.4170 JUN 224.4 143.2 89.9 14.7 9.7 3.1 2023.5003 JUL 227.2 143.9 88.7 14.4 9.9 3.6 2023.5837 AUG 230.1 144.2 88.5 14.3 10.1 4.2 2023.6670 SEP 231.1 144.4 89.1 13.9 10.1 4.5 2023.7503 OCT 229.1 144.8 90.0 13.3 9.9 4.6 2023.8337 NOV 227.4 145.0 91.8 13.2 9.9 4.7 2023.9170 DEC 228.2 145.1 93.7 13.3 10.0 4.9 2024.0003 JAN 227.9 144.5 94.9 12.8 9.8 4.7 2024.0837 FEB 225.0 143.4 95.8 12.6 9.7 4.9 2024.1670 MAR 221.3 142.7 96.7 12.1 9.3 5.2 2024.2503 APR 218.0 142.5 97.5 12.0 8.8 5.1 2024.3337 MAY 216.9 142.8 98.5 12.5 8.7 4.9 2024.4170 JUN 217.1 143.2 99.8 13.6 8.7 4.6 2024.5003 JUL 216.6 143.3 101.2 14.5 8.7 4.6 2024.5837 AUG 215.0 143.2 102.1 15.0 8.8 4.9 2024.6670 SEP 212.8 142.8 102.4 15.8 8.8 5.0 2024.7503 OCT 211.3 142.4 102.9 15.9 8.8 4.8 2024.8337 NOV 211.7 142.3 102.3 15.4 9.0 5.0 2024.9170 DEC 212.2 142.1 101.4 15.4 9.0 5.1 2025.0003 JAN 211.1 141.3 101.1 14.6 9.0 5.7 2025.0837 FEB 208.0 140.2 101.0 12.8 9.0 5.6 2025.1670 MAR 204.6 138.7 99.2 12.8 9.3 5.6 2025.2503 APR 202.2 137.1 98.4 13.3 9.6 5.8 2025.3337 MAY 199.3 135.6 97.4 14.1 9.9 6.1 2025.4170 JUN 195.1 134.4 96.6 15.2 10.3 6.7 2025.5003 JUL 191.7 133.0 96.1 16.1 10.6 7.2 2025.5837 AUG 188.6 131.3 95.7 16.9 10.5 7.0 2025.6670 SEP 185.0 129.5 95.6 17.3 10.5 7.0 2025.7503 OCT 182.0 128.1 95.7 17.8 10.8 7.0 2025.8337 NOV 178.4 127.0 95.4 17.8 10.8 6.9 2025.9170 DEC 175.7 125.9 95.4 17.1 10.8 6.7 2026.0003 JAN 172.3 124.4 95.2 16.1 10.8 6.5 2026.0837 FEB 168.6 122.6 94.0 14.8 10.9 6.4 2026.1670 MAR 166.0 121.4 93.3 14.2 11.3 6.9 2026.2503 APR 163.6 120.5 91.7 14.5 11.7 7.4 2026.3337 MAY 161.4 119.2 89.7 15.1 11.9 8.3 2026.4170 JUN 158.0 117.7 89.1 15.2 12.0 8.0 2026.5003 JUL 153.1 116.0 89.0 14.7 12.2 8.2 2026.5837 AUG 148.3 114.4 88.2 15.6 12.3 8.7 2026.6670 SEP 144.0 112.8 87.1 16.9 12.5 9.0 2026.7503 OCT 139.7 110.9 85.8 17.8 12.6 9.7 2026.8337 NOV 135.4 109.0 84.7 18.3 12.9 9.1 2026.9170 DEC 132.1 107.3 84.5 18.1 13.2 8.9 2027.0003 JAN 129.3 105.7 84.4 18.5 13.4 8.7 2027.0837 FEB 126.4 104.1 83.8 18.4 13.5 8.3 2027.1670 MAR 125.1 102.6 83.9 18.5 13.4 8.1 2027.2503 APR 125.2 101.3 83.5 19.0 13.3 8.1 2027.3337 MAY 125.2 99.9 83.0 19.3 13.1 7.9 2027.4170 JUN 125.0 98.3 81.6 19.8 12.8 7.0 2027.5003 JUL 124.6 97.0 80.5 20.3 12.4 6.0 2027.5837 AUG 123.7 95.8 79.2 20.6 12.0 5.7 2027.6670 SEP 123.3 94.7 78.2 20.9 11.8 5.5 2027.7503 OCT 122.2 93.7 77.7 21.1 11.7 5.4 2027.8337 NOV 120.1 92.8 77.4 20.8 11.4 5.2 2027.9170 DEC 117.9 91.9 76.8 20.0 11.1 5.1 2028.0003 JAN 116.2 90.8 75.9 19.0 10.9 5.2 2028.0837 FEB 115.5 89.8 75.0 18.3 10.9 5.6 2028.1670 MAR 114.4 89.0 74.0 18.1 11.1 5.9 2028.2503 APR 112.0 88.1 73.6 17.7 11.1 5.5 2028.3337 MAY 108.4 87.0 73.1 17.5 11.4 5.0 2028.4170 JUN 105.8 86.0 72.7 17.3 11.6 5.0 2028.5003 JUL 103.8 85.2 72.4 17.7 11.8 5.5 2028.5837 AUG 102.2 84.4 72.3 18.1 11.8 6.1 2028.6670 SEP 100.8 83.5 72.0 18.3 11.7 6.4 2028.7503 OCT 98.8 82.4 71.7 18.4 11.5 6.4 2028.8337 NOV 96.6 81.4 71.4 18.3 11.5 6.6 2028.9170 DEC 95.6 80.7 71.4 18.1 11.7 6.8 2029.0003 JAN 95.1 80.1 71.2 17.8 12.1 7.1 2029.0837 FEB 93.8 79.5 71.1 17.2 12.2 7.3 2029.1670 MAR 91.5 78.7 70.9 16.3 12.2 7.2 2029.2503 APR 89.6 78.0 70.5 16.5 11.9 7.0 2029.3337 MAY 88.1 77.3 70.2 16.5 11.6 6.9 2029.4170 JUN 86.7 76.7 70.0 16.5 11.4 6.5 2029.5003 JUL 85.5 76.1 70.0 16.6 11.3 6.0 2029.5837 AUG 84.8 75.7 69.9 16.8 11.4 5.9 2029.6670 SEP 83.5 75.2 69.8 17.2 11.5 6.2 2029.7503 OCT 81.8 74.7 69.5 17.2 11.5 6.6 2029.8337 NOV 80.2 74.2 69.5 17.0 11.3 6.6 2029.9170 DEC 79.3 73.5 69.1 16.7 11.1 6.4 2030.0003 JAN 78.2 72.9 68.8 15.6 10.6 6.3 2030.0837 FEB 77.2 72.3 68.4 14.1 10.0 6.3 2030.1670 MAR 76.7 71.9 68.2 12.9 9.6 6.2 2030.2503 APR 76.4 71.6 68.1 13.0 9.3 6.1 2030.3337 MAY 76.2 71.2 68.0 12.7 8.9 5.9 2030.4170 JUN 75.8 70.9 67.9 12.3 8.6 5.8 2030.5003 JUL 75.1 70.6 67.6 12.1 8.5 5.7 2030.5837 AUG 74.1 70.3 67.3 11.8 8.3 5.3 2030.6670 SEP 73.0 70.0 67.1 11.0 8.0 4.7 2030.7503 OCT 72.6 69.8 66.9 10.5 7.7 4.2 2030.8337 NOV 72.4 69.6 67.0 10.3 7.5 3.9 2030.9170 DEC 72.4 69.6 67.0 10.4 7.6 4.0 2031.0003 JAN 72.6 69.8 67.0 10.7 7.7 3.8 2031.0837 FEB 73.4 70.1 67.1 11.0 8.0 3.9 2031.1670 MAR 74.3 70.5 67.2 11.2 8.2 3.8 2031.2503 APR 75.1 70.9 67.3 11.5 8.3 3.6 2031.3337 MAY 76.3 71.3 67.4 11.7 8.5 3.4 2031.4170 JUN 78.0 71.9 67.6 11.8 8.7 3.4 2031.5003 JUL 79.5 72.6 67.7 12.0 8.8 3.4 2031.5837 AUG 80.9 73.4 67.8 12.4 9.1 3.3 2031.6670 SEP 83.2 74.2 68.0 12.8 9.5 3.4 2031.7503 OCT 86.2 75.2 68.1 13.2 9.9 3.7 2031.8337 NOV 90.9 76.4 68.4 13.8 10.4 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