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% 2023.3337 MAY 163.3 157.3 153.9 11.3 10.5 9.9 2023.4170 JUN 168.8 158.0 151.5 11.4 10.3 9.2 2023.5003 JUL 175.4 158.5 149.4 11.9 10.4 9.2 2023.5837 AUG 179.9 158.8 146.7 12.5 10.6 9.4 2023.6670 SEP 183.3 158.9 143.1 13.1 10.7 9.2 2023.7503 OCT 186.0 159.0 140.5 13.5 10.6 8.9 2023.8337 NOV 187.9 158.8 138.3 13.5 10.7 8.6 2023.9170 DEC 191.9 158.5 135.8 13.6 10.8 8.8 2024.0003 JAN 193.3 157.6 135.4 14.0 10.8 8.3 2024.0837 FEB 190.0 156.3 134.1 14.6 11.0 8.3 2024.1670 MAR 186.9 155.3 131.2 14.5 11.0 8.0 2024.2503 APR 187.3 154.8 127.7 14.0 10.8 7.5 2024.3337 MAY 188.5 155.0 126.0 13.6 10.7 7.9 2024.4170 JUN 188.6 155.2 126.3 14.5 10.8 8.2 2024.5003 JUL 188.2 155.1 125.6 15.5 10.9 8.1 2024.5837 AUG 187.2 154.8 125.0 16.2 11.1 8.3 2024.6670 SEP 185.2 154.4 123.1 17.0 11.2 8.3 2024.7503 OCT 181.3 153.9 120.0 17.1 11.2 8.3 2024.8337 NOV 179.0 153.7 118.3 16.5 11.3 8.3 2024.9170 DEC 176.4 153.3 117.0 16.5 11.4 8.2 2025.0003 JAN 175.1 152.4 115.3 16.4 11.6 8.3 2025.0837 FEB 176.9 151.1 114.1 17.2 11.7 8.1 2025.1670 MAR 178.5 149.3 111.9 17.2 11.9 8.1 2025.2503 APR 178.6 147.6 110.2 16.9 12.1 8.1 2025.3337 MAY 178.4 146.0 108.4 17.1 12.4 8.4 2025.4170 JUN 178.7 144.6 107.4 17.8 12.7 8.6 2025.5003 JUL 179.4 142.9 106.5 18.6 13.0 8.9 2025.5837 AUG 179.1 140.9 105.4 19.4 13.1 8.9 2025.6670 SEP 176.6 138.6 104.5 20.2 13.3 8.8 2025.7503 OCT 174.0 136.6 102.9 20.5 13.6 8.9 2025.8337 NOV 173.1 134.9 101.6 20.7 13.7 8.8 2025.9170 DEC 173.0 133.4 100.2 21.3 13.9 8.7 2026.0003 JAN 171.4 131.5 97.6 22.0 14.1 8.7 2026.0837 FEB 168.4 129.5 94.6 22.1 14.3 8.6 2026.1670 MAR 164.8 128.1 93.4 22.0 14.6 9.0 2026.2503 APR 161.4 126.9 93.1 22.3 14.9 9.5 2026.3337 MAY 159.5 125.3 92.7 22.7 15.3 10.5 2026.4170 JUN 158.0 123.6 92.4 22.8 15.5 11.1 2026.5003 JUL 154.9 121.6 91.8 22.2 15.6 11.3 2026.5837 AUG 149.5 119.5 90.9 21.3 15.7 11.5 2026.6670 SEP 145.3 117.6 89.6 20.9 15.7 11.8 2026.7503 OCT 143.0 115.6 88.0 21.5 15.7 11.6 2026.8337 NOV 142.0 113.6 85.7 21.6 15.8 11.6 2026.9170 DEC 140.4 111.8 84.2 21.8 15.9 11.5 2027.0003 JAN 137.9 110.2 83.8 22.0 15.9 11.3 2027.0837 FEB 135.0 108.5 83.1 21.5 15.8 11.2 2027.1670 MAR 132.2 106.7 82.3 21.3 15.4 11.1 2027.2503 APR 129.6 105.1 80.8 21.4 15.1 10.6 2027.3337 MAY 128.0 103.4 78.4 21.5 14.8 10.0 2027.4170 JUN 126.7 101.6 77.0 22.0 14.5 9.1 2027.5003 JUL 125.4 100.0 76.3 22.5 14.2 8.1 2027.5837 AUG 124.2 98.7 75.0 22.8 13.8 7.7 2027.6670 SEP 123.8 97.5 74.2 23.2 13.7 7.4 2027.7503 OCT 122.8 96.4 73.8 23.5 13.7 7.5 2027.8337 NOV 121.0 95.5 73.6 23.4 13.6 7.7 2027.9170 DEC 118.9 94.5 73.1 23.1 13.5 8.3 2028.0003 JAN 117.0 93.2 72.4 22.5 13.5 9.0 2028.0837 FEB 116.1 92.0 71.8 21.9 13.6 8.8 2028.1670 MAR 114.9 91.0 71.6 21.8 13.8 8.4 2028.2503 APR 112.3 89.8 71.5 21.6 13.9 7.8 2028.3337 MAY 109.4 88.5 71.5 21.4 14.1 7.2 2028.4170 JUN 106.8 87.4 71.6 21.0 14.2 7.1 2028.5003 JUL 104.3 86.6 71.4 20.4 14.2 7.5 2028.5837 AUG 102.5 85.6 71.4 19.7 14.1 7.9 2028.6670 SEP 101.2 84.6 71.5 19.9 13.9 8.3 2028.7503 OCT 99.3 83.4 71.4 19.9 13.6 8.2 2028.8337 NOV 97.2 82.4 70.8 19.6 13.5 8.2 2028.9170 DEC 95.9 81.7 71.0 19.3 13.4 8.1 2029.0003 JAN 95.0 81.0 71.1 18.8 13.4 8.2 2029.0837 FEB 94.1 80.3 70.9 18.0 13.3 8.1 2029.1670 MAR 92.3 79.5 70.7 17.1 13.2 7.9 2029.2503 APR 91.5 78.9 70.5 17.3 12.9 7.3 2029.3337 MAY 90.7 78.2 70.4 17.4 12.8 7.0 2029.4170 JUN 89.7 77.6 70.3 17.5 12.7 6.8 2029.5003 JUL 88.7 77.0 70.3 17.5 12.7 6.6 2029.5837 AUG 87.8 76.4 70.1 17.6 12.7 6.7 2029.6670 SEP 86.3 75.9 70.0 17.9 12.6 6.5 2029.7503 OCT 84.8 75.4 70.0 18.0 12.6 6.3 2029.8337 NOV 82.8 74.9 69.9 17.7 12.4 6.3 2029.9170 DEC 80.6 74.2 69.5 17.5 12.1 6.1 2030.0003 JAN 79.4 73.5 69.3 16.5 11.8 6.0 2030.0837 FEB 78.4 72.9 69.0 15.1 11.5 5.9 2030.1670 MAR 77.9 72.4 68.7 14.0 11.1 5.9 2030.2503 APR 77.7 72.0 68.5 14.2 10.8 6.0 2030.3337 MAY 77.5 71.7 68.2 13.8 10.4 6.0 2030.4170 JUN 77.3 71.3 67.9 13.4 10.0 5.9 2030.5003 JUL 76.5 71.0 67.8 13.0 9.7 5.8 2030.5837 AUG 75.4 70.7 67.7 12.7 9.4 5.7 2030.6670 SEP 74.3 70.4 67.4 11.9 9.2 5.8 2030.7503 OCT 74.0 70.2 67.4 11.4 8.9 5.2 2030.8337 NOV 73.6 70.1 67.4 11.2 8.7 4.9 2030.9170 DEC 73.5 70.0 67.4 11.2 8.7 4.9 2031.0003 JAN 73.6 70.1 67.3 11.4 8.7 4.6 2031.0837 FEB 74.3 70.4 67.4 11.7 8.9 4.6 2031.1670 MAR 75.1 70.8 67.5 11.8 9.0 4.5 2031.2503 APR 75.8 71.1 67.5 12.0 9.0 4.2 2031.3337 MAY 76.9 71.5 67.6 12.1 9.1 3.9 2031.4170 JUN 78.5 72.1 67.7 12.2 9.2 3.8 2031.5003 JUL 79.9 72.8 67.8 12.3 9.2 3.7 2031.5837 AUG 81.2 73.5 67.9 12.6 9.4 3.6 2031.6670 SEP 83.4 74.3 68.0 12.9 9.7 3.6 2031.7503 OCT 86.3 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