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% 2021.4170 JUN 84.2 82.2 79.9 7.9 7.1 6.6 2021.5003 JUL 88.4 84.0 79.7 8.1 7.3 6.4 2021.5837 AUG 92.7 86.1 79.9 8.7 7.5 6.4 2021.6670 SEP 96.4 88.4 81.1 9.1 7.7 6.9 2021.7503 OCT 100.1 90.7 82.6 10.3 7.8 7.0 2021.8337 NOV 105.3 93.0 83.9 10.9 7.9 6.8 2021.9170 DEC 111.4 95.5 84.8 11.2 8.1 6.4 2022.0003 JAN 117.0 98.1 85.2 11.5 8.3 6.5 2022.0837 FEB 122.9 100.6 85.6 12.2 8.6 7.0 2022.1670 MAR 130.0 103.2 86.3 13.1 9.1 7.4 2022.2503 APR 137.5 106.0 86.9 13.9 9.6 7.6 2022.3337 MAY 142.4 108.8 87.7 14.6 10.0 7.9 2022.4170 JUN 147.8 111.6 88.4 15.0 10.3 7.5 2022.5003 JUL 153.6 114.1 88.4 14.7 10.4 7.0 2022.5837 AUG 158.3 116.1 89.6 14.9 10.5 6.8 2022.6670 SEP 162.7 118.1 88.9 14.8 10.6 6.6 2022.7503 OCT 168.9 120.3 87.2 14.2 10.8 6.5 2022.8337 NOV 176.1 122.7 85.6 14.5 11.0 6.1 2022.9170 DEC 182.3 125.1 83.5 14.9 11.1 5.8 2023.0003 JAN 187.7 127.2 81.6 15.0 11.3 5.5 2023.0837 FEB 191.5 129.1 80.5 15.5 11.5 5.2 2023.1670 MAR 195.1 130.8 80.1 15.5 11.5 5.1 2023.2503 APR 199.2 132.5 81.7 15.7 11.5 5.1 2023.3337 MAY 202.3 133.8 82.6 16.6 11.4 4.9 2023.4170 JUN 203.3 134.9 82.2 16.7 11.3 4.8 2023.5003 JUL 201.7 135.9 81.9 16.4 11.4 5.3 2023.5837 AUG 200.1 136.5 80.8 16.2 11.6 5.9 2023.6670 SEP 199.3 137.0 80.3 15.9 11.6 6.4 2023.7503 OCT 199.7 137.6 82.5 15.4 11.5 6.5 2023.8337 NOV 200.0 138.1 84.7 15.4 11.5 6.7 2023.9170 DEC 201.7 138.5 87.0 15.2 11.5 6.8 2024.0003 JAN 201.7 138.0 86.8 14.8 11.5 6.9 2024.0837 FEB 199.1 137.1 85.3 15.3 11.7 7.6 2024.1670 MAR 196.2 136.5 84.5 15.7 11.4 8.0 2024.2503 APR 193.4 136.6 83.4 16.1 11.1 7.3 2024.3337 MAY 191.8 137.1 81.8 16.9 11.0 7.5 2024.4170 JUN 191.6 137.6 80.2 18.3 11.2 7.8 2024.5003 JUL 191.2 137.8 78.7 19.5 11.4 8.1 2024.5837 AUG 190.3 138.0 76.4 20.2 11.6 8.1 2024.6670 SEP 189.1 137.9 74.3 21.3 11.9 8.1 2024.7503 OCT 189.1 137.7 72.0 21.7 11.9 7.7 2024.8337 NOV 189.3 137.6 70.9 21.0 12.0 7.7 2024.9170 DEC 190.2 137.5 70.5 20.9 12.0 7.5 2025.0003 JAN 189.5 136.8 69.5 20.1 12.0 7.1 2025.0837 FEB 187.6 135.8 69.1 18.1 11.9 6.6 2025.1670 MAR 185.8 134.6 68.8 16.5 12.0 6.5 2025.2503 APR 184.6 133.3 69.0 16.3 12.3 6.7 2025.3337 MAY 182.9 132.1 68.6 16.6 12.6 7.1 2025.4170 JUN 179.8 131.2 69.2 16.9 12.7 7.5 2025.5003 JUL 180.3 130.1 70.5 17.3 12.7 7.7 2025.5837 AUG 180.2 128.7 72.0 18.0 12.6 7.3 2025.6670 SEP 178.1 127.2 74.1 18.3 12.6 7.2 2025.7503 OCT 176.6 126.1 76.4 18.6 12.7 7.7 2025.8337 NOV 176.3 125.2 78.1 18.5 12.7 7.5 2025.9170 DEC 175.4 124.5 80.0 17.9 12.8 7.4 2026.0003 JAN 173.2 123.1 81.9 17.0 12.9 7.3 2026.0837 FEB 169.9 121.5 82.4 16.2 12.9 7.2 2026.1670 MAR 166.7 120.5 82.2 16.7 13.2 7.6 2026.2503 APR 163.8 119.6 81.7 17.0 13.4 8.1 2026.3337 MAY 162.0 118.3 80.6 17.1 13.6 8.9 2026.4170 JUN 160.5 116.9 80.2 17.3 13.8 9.5 2026.5003 JUL 157.2 115.4 80.4 17.7 14.0 9.7 2026.5837 AUG 151.7 113.9 80.6 19.0 14.2 10.0 2026.6670 SEP 146.5 112.4 80.1 20.1 14.2 10.4 2026.7503 OCT 143.4 110.7 79.3 20.8 14.3 10.8 2026.8337 NOV 141.3 108.9 78.8 20.9 14.5 11.4 2026.9170 DEC 139.7 107.3 78.7 20.5 14.6 11.0 2027.0003 JAN 137.0 105.8 78.7 19.9 14.6 10.4 2027.0837 FEB 133.9 104.3 78.6 19.1 14.6 9.9 2027.1670 MAR 130.6 103.0 78.7 18.4 14.3 9.5 2027.2503 APR 128.3 101.8 78.9 18.5 14.0 9.0 2027.3337 MAY 125.6 100.5 78.0 18.4 13.6 8.3 2027.4170 JUN 121.1 99.1 77.0 18.5 13.2 7.1 2027.5003 JUL 119.7 97.8 75.8 18.6 12.7 5.9 2027.5837 AUG 119.2 96.5 74.4 18.6 12.2 5.5 2027.6670 SEP 119.0 95.4 73.7 18.7 12.0 5.2 2027.7503 OCT 118.1 94.3 73.1 18.8 11.9 5.0 2027.8337 NOV 117.5 93.3 72.7 18.4 11.6 4.8 2027.9170 DEC 117.1 92.4 72.5 17.7 11.4 4.9 2028.0003 JAN 116.1 91.3 72.1 17.1 11.3 5.3 2028.0837 FEB 114.7 90.4 71.8 16.5 11.4 5.8 2028.1670 MAR 113.2 89.7 71.8 16.5 11.6 6.1 2028.2503 APR 110.0 88.9 71.5 16.4 11.7 5.5 2028.3337 MAY 105.8 87.8 71.1 16.8 12.1 5.1 2028.4170 JUN 103.3 86.8 70.7 17.2 12.3 5.1 2028.5003 JUL 101.9 86.1 70.4 17.7 12.5 5.6 2028.5837 AUG 100.4 85.3 70.2 18.2 12.4 6.2 2028.6670 SEP 97.6 84.5 69.8 18.5 12.4 6.6 2028.7503 OCT 96.0 83.4 69.4 18.6 12.2 6.6 2028.8337 NOV 94.2 82.3 69.3 18.4 12.2 6.8 2028.9170 DEC 93.1 81.6 69.4 18.2 12.3 6.9 2029.0003 JAN 93.0 80.9 69.4 17.9 12.5 7.2 2029.0837 FEB 92.2 80.1 69.3 17.3 12.6 7.3 2029.1670 MAR 91.3 79.2 69.1 16.8 12.6 7.3 2029.2503 APR 90.2 78.4 68.8 17.1 12.4 7.2 2029.3337 MAY 89.3 77.7 68.6 17.2 12.2 7.1 2029.4170 JUN 88.2 77.0 68.5 17.3 12.1 6.9 2029.5003 JUL 87.2 76.4 68.5 17.3 12.1 6.5 2029.5837 AUG 86.5 76.0 68.5 17.5 12.2 6.4 2029.6670 SEP 85.1 75.5 68.5 17.9 12.3 6.6 2029.7503 OCT 83.8 75.1 68.5 17.8 12.2 6.5 2029.8337 NOV 81.9 74.5 68.4 17.5 12.0 6.4 2029.9170 DEC 79.6 73.8 68.4 17.2 11.8 6.2 2030.0003 JAN 78.1 73.1 68.2 16.2 11.3 6.2 2030.0837 FEB 77.4 72.5 67.9 14.7 10.8 6.2 2030.1670 MAR 77.0 72.1 67.7 13.4 10.4 6.2 2030.2503 APR 76.9 71.8 67.7 13.4 10.0 6.3 2030.3337 MAY 76.6 71.4 67.5 13.1 9.6 6.4 2030.4170 JUN 76.4 71.1 67.4 12.7 9.3 6.2 2030.5003 JUL 76.0 70.7 67.3 12.5 9.1 6.0 2030.5837 AUG 74.9 70.4 67.3 12.2 8.9 5.7 2030.6670 SEP 73.9 70.1 67.3 11.4 8.6 5.2 2030.7503 OCT 73.5 69.9 67.3 10.9 8.4 4.7 2030.8337 NOV 73.1 69.7 67.2 10.7 8.1 4.3 2030.9170 DEC 73.1 69.7 67.2 10.7 8.2 4.3 2031.0003 JAN 73.2 69.8 67.2 11.0 8.3 4.2 2031.0837 FEB 73.9 70.1 67.2 11.3 8.5 4.2 2031.1670 MAR 74.8 70.5 67.3 11.4 8.6 4.1 2031.2503 APR 75.5 70.9 67.4 11.7 8.7 3.8 2031.3337 MAY 76.6 71.3 67.5 11.8 8.8 3.7 2031.4170 JUN 78.3 71.9 67.7 12.0 8.9 3.6 2031.5003 JUL 79.7 72.6 67.8 12.1 9.1 3.5 2031.5837 AUG 81.1 73.4 67.9 12.5 9.3 3.4 2031.6670 SEP 83.3 74.2 68.0 12.8 9.6 3.5 2031.7503 OCT 86.2 75.2 68.1 13.2 10.0 3.8 2031.8337 NOV 90.8 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