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% 2021.0003 JAN 78.7 77.6 76.7 7.2 6.6 6.0 2021.0837 FEB 81.6 79.1 77.3 7.9 6.6 5.2 2021.1670 MAR 84.6 80.7 77.9 8.5 6.6 4.6 2021.2503 APR 88.0 82.5 78.1 8.8 6.6 4.1 2021.3337 MAY 92.3 84.4 78.9 9.3 6.8 3.9 2021.4170 JUN 97.4 86.5 79.1 10.0 7.0 4.0 2021.5003 JUL 103.0 88.7 78.8 10.2 7.2 4.2 2021.5837 AUG 108.5 91.3 79.0 10.4 7.4 4.7 2021.6670 SEP 113.1 93.8 80.2 10.6 7.5 4.7 2021.7503 OCT 117.7 96.4 81.7 10.4 7.4 4.9 2021.8337 NOV 123.6 99.0 83.3 10.4 7.4 5.0 2021.9170 DEC 130.7 101.8 84.5 10.8 7.5 5.3 2022.0003 JAN 137.2 104.7 85.0 10.8 7.7 5.6 2022.0837 FEB 144.0 107.6 85.7 11.5 8.0 5.7 2022.1670 MAR 151.8 110.5 86.7 11.8 8.4 6.1 2022.2503 APR 159.5 113.5 88.2 11.7 8.8 6.7 2022.3337 MAY 164.3 116.6 89.9 11.9 9.0 6.5 2022.4170 JUN 167.8 119.5 91.8 12.6 9.4 6.1 2022.5003 JUL 171.5 122.0 93.1 13.3 9.6 5.9 2022.5837 AUG 174.8 124.1 93.4 13.4 9.7 5.7 2022.6670 SEP 179.1 126.2 93.4 13.9 10.0 5.8 2022.7503 OCT 185.2 128.6 94.1 14.7 10.4 6.0 2022.8337 NOV 190.3 131.1 94.6 15.4 10.6 5.7 2022.9170 DEC 194.7 133.4 93.4 15.8 10.8 5.6 2023.0003 JAN 199.2 135.5 91.9 15.9 11.0 5.3 2023.0837 FEB 203.5 137.4 92.0 16.4 11.2 5.0 2023.1670 MAR 206.5 139.1 92.9 16.6 11.2 4.9 2023.2503 APR 209.1 140.7 94.8 17.1 11.2 4.9 2023.3337 MAY 211.4 141.9 95.6 18.1 11.3 5.0 2023.4170 JUN 213.3 142.8 94.9 18.2 11.3 5.1 2023.5003 JUL 215.6 143.6 94.7 17.7 11.4 5.6 2023.5837 AUG 218.2 144.1 93.8 17.4 11.6 6.1 2023.6670 SEP 220.1 144.5 93.6 17.0 11.6 6.5 2023.7503 OCT 220.1 145.0 96.4 16.5 11.4 6.6 2023.8337 NOV 219.9 145.3 98.6 16.4 11.4 6.8 2023.9170 DEC 221.0 145.4 100.8 16.2 11.5 6.9 2024.0003 JAN 220.9 144.9 100.7 15.6 11.4 6.8 2024.0837 FEB 218.0 143.8 99.1 15.0 11.3 7.2 2024.1670 MAR 214.6 143.1 97.8 14.4 11.0 7.4 2024.2503 APR 211.3 143.0 96.2 14.2 10.5 7.0 2024.3337 MAY 209.3 143.4 94.3 14.4 10.4 6.9 2024.4170 JUN 208.9 143.8 92.5 15.1 10.4 6.6 2024.5003 JUL 208.2 143.9 90.9 16.1 10.5 6.4 2024.5837 AUG 206.8 143.9 88.1 16.6 10.7 6.6 2024.6670 SEP 205.3 143.6 85.4 17.5 10.7 6.5 2024.7503 OCT 204.2 143.2 82.3 17.7 10.8 6.6 2024.8337 NOV 204.1 143.0 80.8 17.1 10.9 7.3 2024.9170 DEC 204.7 142.8 80.1 16.9 10.8 7.2 2025.0003 JAN 204.1 142.0 78.9 16.0 10.7 6.8 2025.0837 FEB 202.8 140.9 78.3 15.2 10.8 6.6 2025.1670 MAR 200.4 139.5 77.4 15.7 11.0 6.6 2025.2503 APR 198.1 137.9 76.6 16.6 11.4 6.8 2025.3337 MAY 195.5 136.5 75.3 16.9 11.6 7.1 2025.4170 JUN 192.2 135.4 75.1 16.7 11.8 7.5 2025.5003 JUL 189.7 134.0 75.8 16.9 12.0 7.7 2025.5837 AUG 187.3 132.4 76.8 16.1 11.7 7.4 2025.6670 SEP 184.4 130.6 78.2 16.4 11.8 7.2 2025.7503 OCT 182.3 129.2 80.3 17.4 12.1 7.3 2025.8337 NOV 181.6 128.1 81.8 17.3 12.1 7.2 2025.9170 DEC 180.9 127.1 83.6 17.2 12.2 7.0 2026.0003 JAN 178.2 125.5 85.3 17.3 12.3 6.9 2026.0837 FEB 174.6 123.8 85.3 17.3 12.5 6.9 2026.1670 MAR 171.0 122.6 84.9 16.4 12.8 7.4 2026.2503 APR 167.7 121.6 84.2 16.1 13.0 7.8 2026.3337 MAY 165.8 120.3 83.0 16.7 13.3 8.7 2026.4170 JUN 164.0 118.8 82.5 17.1 13.6 9.3 2026.5003 JUL 160.4 117.1 82.6 16.9 13.8 9.7 2026.5837 AUG 154.9 115.5 82.7 17.7 13.9 9.9 2026.6670 SEP 149.6 113.9 82.1 18.9 13.9 9.9 2026.7503 OCT 146.2 112.1 81.1 19.4 13.8 10.0 2026.8337 NOV 143.8 110.2 80.3 19.6 13.8 10.1 2026.9170 DEC 141.7 108.5 80.1 19.2 13.9 9.9 2027.0003 JAN 138.9 107.0 79.9 18.5 13.9 10.2 2027.0837 FEB 135.5 105.4 79.6 17.9 13.7 9.5 2027.1670 MAR 131.9 103.9 79.7 17.9 13.6 9.2 2027.2503 APR 129.0 102.6 79.5 18.3 13.4 9.0 2027.3337 MAY 126.1 101.1 78.4 18.3 13.0 8.4 2027.4170 JUN 121.6 99.6 77.2 18.4 12.5 7.2 2027.5003 JUL 120.2 98.1 76.2 18.7 12.0 6.2 2027.5837 AUG 119.6 96.9 74.8 19.1 11.7 6.1 2027.6670 SEP 119.4 95.7 74.0 19.5 11.6 6.1 2027.7503 OCT 118.5 94.7 73.6 19.8 11.6 6.1 2027.8337 NOV 117.7 93.8 73.3 19.6 11.4 6.1 2027.9170 DEC 117.4 92.8 73.1 19.0 11.3 6.3 2028.0003 JAN 116.3 91.7 72.5 18.4 11.2 5.8 2028.0837 FEB 114.9 90.7 72.1 17.8 11.2 5.5 2028.1670 MAR 113.3 89.8 71.9 17.8 11.5 5.2 2028.2503 APR 110.0 88.9 71.6 17.6 11.6 4.6 2028.3337 MAY 105.8 87.8 71.1 17.6 11.9 4.2 2028.4170 JUN 103.2 86.8 70.8 17.5 12.2 4.4 2028.5003 JUL 101.7 86.0 70.5 17.8 12.4 4.9 2028.5837 AUG 100.1 85.2 70.2 18.1 12.3 5.5 2028.6670 SEP 97.7 84.3 69.8 18.4 12.2 5.9 2028.7503 OCT 96.2 83.2 69.4 18.6 12.1 6.0 2028.8337 NOV 94.3 82.1 69.3 18.4 12.1 6.3 2028.9170 DEC 93.3 81.4 69.4 18.3 12.3 6.6 2029.0003 JAN 93.1 80.7 69.4 18.1 12.6 7.0 2029.0837 FEB 92.3 80.0 69.4 17.6 12.9 7.4 2029.1670 MAR 91.1 79.2 69.3 16.8 13.0 7.6 2029.2503 APR 90.1 78.4 69.0 17.1 12.8 7.3 2029.3337 MAY 89.1 77.7 68.8 17.2 12.6 7.1 2029.4170 JUN 88.0 77.0 68.7 17.3 12.4 6.9 2029.5003 JUL 87.1 76.4 68.7 17.3 12.4 6.6 2029.5837 AUG 86.4 76.0 68.6 17.6 12.6 6.7 2029.6670 SEP 85.0 75.5 68.6 18.0 12.6 6.5 2029.7503 OCT 83.7 75.1 68.6 17.9 12.4 6.4 2029.8337 NOV 81.8 74.5 68.5 17.6 12.2 6.4 2029.9170 DEC 79.7 73.9 68.5 17.3 11.8 6.3 2030.0003 JAN 78.3 73.2 68.2 16.2 11.3 6.3 2030.0837 FEB 77.5 72.6 67.9 14.6 10.7 6.3 2030.1670 MAR 77.0 72.1 67.7 13.2 10.2 6.4 2030.2503 APR 76.8 71.8 67.6 13.2 9.8 6.1 2030.3337 MAY 76.6 71.5 67.5 12.8 9.3 5.9 2030.4170 JUN 76.4 71.1 67.4 12.4 9.0 5.7 2030.5003 JUL 76.0 70.8 67.3 12.3 8.8 5.6 2030.5837 AUG 75.0 70.5 67.3 12.0 8.6 5.3 2030.6670 SEP 73.9 70.2 67.3 11.3 8.4 4.7 2030.7503 OCT 73.6 70.0 67.3 10.8 8.2 4.3 2030.8337 NOV 73.2 69.8 67.3 10.6 8.0 3.9 2030.9170 DEC 73.2 69.8 67.3 10.6 8.0 4.0 2031.0003 JAN 73.3 69.9 67.3 10.9 8.2 3.8 2031.0837 FEB 74.0 70.2 67.3 11.2 8.4 3.9 2031.1670 MAR 74.9 70.6 67.4 11.4 8.5 3.9 2031.2503 APR 75.6 71.0 67.5 11.6 8.6 3.6 2031.3337 MAY 76.7 71.4 67.6 11.8 8.8 3.5 2031.4170 JUN 78.4 72.0 67.7 11.9 8.9 3.4 2031.5003 JUL 79.7 72.7 67.8 12.1 9.0 3.4 2031.5837 AUG 81.1 73.4 67.9 12.4 9.2 3.3 2031.6670 SEP 83.3 74.3 68.0 12.8 9.5 3.4 2031.7503 OCT 86.2 75.2 68.1 13.2 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