TABLE 5 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 75.0% 50% 5.0% 95.0% 50% 5.0% 2025.1670 MAR 175.7 174.6 170.6 16.1 14.8 13.3 2025.2503 APR 174.7 172.4 163.3 17.2 15.0 12.8 2025.3337 MAY 176.0 170.5 157.5 18.0 15.1 12.7 2025.4170 JUN 174.4 168.6 152.9 18.8 15.1 11.9 2025.5003 JUL 172.3 166.2 147.7 19.5 15.1 11.1 2025.5837 AUG 171.7 163.5 144.7 20.4 15.1 10.9 2025.6670 SEP 168.4 160.2 140.6 21.0 15.4 10.5 2025.7503 OCT 164.3 157.1 135.3 21.6 15.7 10.1 2025.8337 NOV 161.3 154.4 131.2 21.7 15.9 10.4 2025.9170 DEC 157.8 151.9 128.8 21.2 16.1 10.9 2026.0003 JAN 155.7 148.9 125.4 20.3 16.1 11.0 2026.0837 FEB 154.1 146.1 122.0 20.3 16.1 11.0 2026.1670 MAR 152.3 144.0 119.9 20.5 16.1 11.5 2026.2503 APR 149.4 142.1 118.4 20.9 16.1 11.9 2026.3337 MAY 145.7 139.9 116.9 21.5 16.2 11.9 2026.4170 JUN 143.1 137.4 115.1 21.7 16.4 11.8 2026.5003 JUL 141.0 134.4 113.2 21.2 16.4 12.1 2026.5837 AUG 139.1 131.4 111.9 20.7 16.3 12.7 2026.6670 SEP 134.8 128.9 110.4 21.6 16.2 12.9 2026.7503 OCT 131.2 126.4 107.8 22.0 16.0 12.9 2026.8337 NOV 129.3 123.9 104.2 21.9 16.0 12.5 2026.9170 DEC 129.3 121.8 101.7 22.1 16.0 12.2 2027.0003 JAN 129.6 119.7 100.5 22.5 16.1 12.1 2027.0837 FEB 128.7 117.4 98.9 22.3 16.1 12.2 2027.1670 MAR 125.6 115.0 96.8 22.3 15.9 11.7 2027.2503 APR 123.0 112.9 94.1 22.6 15.7 11.5 2027.3337 MAY 121.1 110.8 90.8 22.8 15.4 11.0 2027.4170 JUN 117.8 108.2 88.0 23.4 15.2 10.1 2027.5003 JUL 115.5 106.1 85.8 24.0 14.9 9.4 2027.5837 AUG 113.2 104.5 84.0 24.7 14.8 9.4 2027.6670 SEP 111.8 103.1 83.0 25.2 14.7 9.4 2027.7503 OCT 111.5 101.9 82.3 25.4 14.7 9.4 2027.8337 NOV 110.1 100.9 82.1 25.3 14.5 9.6 2027.9170 DEC 108.4 99.9 81.6 24.8 14.4 9.8 2028.0003 JAN 106.8 98.4 80.5 23.9 14.2 9.8 2028.0837 FEB 105.0 96.9 79.4 23.0 14.1 9.2 2028.1670 MAR 102.5 95.4 78.4 22.5 14.1 8.7 2028.2503 APR 101.5 93.9 77.9 22.1 14.2 8.0 2028.3337 MAY 101.1 92.3 77.5 21.8 14.3 7.4 2028.4170 JUN 99.3 91.0 77.3 21.4 14.4 7.3 2028.5003 JUL 97.6 89.9 77.0 20.8 14.4 7.7 2028.5837 AUG 95.7 88.8 76.5 19.9 14.2 8.1 2028.6670 SEP 93.1 87.3 76.0 20.1 14.1 8.4 2028.7503 OCT 93.1 85.8 75.2 20.3 13.9 8.4 2028.8337 NOV 91.5 84.5 74.2 20.0 13.7 8.4 2028.9170 DEC 89.9 83.5 73.8 19.6 13.6 8.3 2029.0003 JAN 88.2 82.6 73.3 19.0 13.6 8.3 2029.0837 FEB 87.2 81.7 72.8 18.3 13.6 8.4 2029.1670 MAR 86.5 81.0 72.6 17.4 13.5 8.1 2029.2503 APR 85.2 80.3 72.3 17.5 13.3 7.8 2029.3337 MAY 83.7 79.7 72.0 17.6 13.1 7.7 2029.4170 JUN 82.5 79.0 71.9 17.8 13.0 7.7 2029.5003 JUL 81.3 78.3 71.8 17.8 12.9 7.2 2029.5837 AUG 80.6 77.7 71.6 17.8 12.8 7.0 2029.6670 SEP 80.4 77.2 71.6 17.8 12.7 7.2 2029.7503 OCT 80.1 76.8 71.6 17.8 12.5 6.9 2029.8337 NOV 79.0 76.2 71.4 17.5 12.3 6.8 2029.9170 DEC 78.4 75.5 71.3 17.2 12.0 6.6 2030.0003 JAN 77.2 74.8 70.8 16.2 11.6 6.5 2030.0837 FEB 76.5 74.0 70.2 14.8 11.2 6.4 2030.1670 MAR 75.6 73.4 69.8 13.9 10.9 6.3 2030.2503 APR 74.7 73.0 69.6 14.0 10.5 6.3 2030.3337 MAY 74.1 72.6 69.6 13.7 10.2 6.3 2030.4170 JUN 73.0 72.2 69.4 13.2 9.8 6.1 2030.5003 JUL 72.9 71.9 68.9 12.9 9.5 5.9 2030.5837 AUG 72.4 71.6 68.6 12.6 9.3 5.8 2030.6670 SEP 72.1 71.3 68.3 11.9 9.1 5.7 2030.7503 OCT 72.0 71.2 68.1 11.4 8.9 5.2 2030.8337 NOV 71.8 71.0 68.2 11.3 8.7 4.9 2030.9170 DEC 71.8 70.9 68.1 11.2 8.7 4.9 2031.0003 JAN 72.0 70.9 68.0 11.4 8.7 4.6 2031.0837 FEB 72.5 71.1 68.0 11.7 8.9 4.6 2031.1670 MAR 73.2 71.4 68.0 11.8 9.0 4.5 2031.2503 APR 73.2 71.7 68.0 12.0 9.0 4.2 2031.3337 MAY 73.3 72.0 68.0 12.1 9.1 3.9 2031.4170 JUN 74.3 72.5 68.1 12.2 9.2 3.8 2031.5003 JUL 75.7 73.1 68.1 12.3 9.2 3.7 2031.5837 AUG 76.2 73.7 68.2 12.6 9.4 3.6 2031.6670 SEP 77.0 74.5 68.2 12.9 9.7 3.5 2031.7503 OCT 78.3 75.3 68.2 13.3 10.0 3.8 2031.8337 NOV 80.0 76.4 68.4 13.8 10.3 4.2 2031.9170 DEC 82.4 77.8 68.5 14.6 10.6 4.5 2032.0003 JAN 85.7 79.4 68.5 15.7 10.9 4.7 2032.0837 FEB 88.4 81.1 68.5 16.1 11.1 4.8 2032.1670 MAR 91.6 83.1 68.5 16.3 11.3 5.0 2032.2503 APR 94.6 85.2 68.4 16.9 11.4 5.1 2032.3337 MAY 97.2 87.5 68.6 18.0 11.6 5.3 2032.4170 JUN 99.1 89.9 68.7 18.9 11.9 5.4 2032.5003 JUL 103.2 92.5 69.0 19.1 12.1 5.6 2032.5837 AUG 108.1 95.3 69.3 19.2 12.3 5.8 2032.6670 SEP 112.2 98.1 69.4 19.0 12.6 6.0 2032.7503 OCT 116.5 100.9 69.6 18.6 12.7 6.1 2032.8337 NOV 120.0 103.7 70.1 18.5 12.7 6.1 2032.9170 DEC 122.7 106.7 70.8 18.9 12.8 6.1 2033.0003 JAN 125.5 109.8 71.0 18.8 12.9 6.3 2033.0837 FEB 129.4 113.0 71.4 17.8 13.0 6.5 2033.1670 MAR 133.2 116.2 71.7 17.9 13.2 6.7 2033.2503 APR 137.5 119.3 72.3 18.4 13.4 7.1 2033.3337 MAY 143.0 122.6 73.1 19.1 13.7 7.0 2033.4170 JUN 148.7 125.6 73.5 19.6 14.2 7.0 2033.5003 JUL 153.5 128.1 74.3 20.3 14.5 7.1 2033.5837 AUG 157.2 130.2 74.9 20.3 14.5 7.2 2033.6670 SEP 163.0 132.5 75.3 20.3 14.6 7.7 2033.7503 OCT 169.0 135.1 75.8 20.5 14.7 8.1 2033.8337 NOV 173.9 137.6 76.2 20.8 14.8 8.0 2033.9170 DEC 179.8 139.9 76.5 21.2 14.8 8.0 2034.0003 JAN 181.7 141.9 76.5 21.3 14.6 8.4 2034.0837 FEB 184.2 143.7 76.5 21.4 14.6 8.6 2034.1670 MAR 185.0 145.3 76.8 21.6 14.6 8.4 2034.2503 APR 184.8 146.8 77.3 22.0 14.5 8.4 2034.3337 MAY 184.0 147.9 77.8 22.7 14.4 8.6 2034.4170 JUN 183.8 148.7 78.5 22.4 14.1 8.6 2034.5003 JUL 185.2 149.3 79.8 21.3 13.8 8.5 2034.5837 AUG 186.7 149.6 80.6 20.6 13.7 8.3 2034.6670 SEP 187.4 149.9 81.6 20.1 13.6 8.0 2034.7503 OCT 187.1 150.2 83.1 19.7 13.5 7.6 2034.8337 NOV 185.9 150.3 84.6 19.6 13.5 7.5 2034.9170 DEC 186.2 150.3 86.2 19.3 13.5 7.8 2035.0003 JAN 184.1 149.6 87.0 19.1 13.7 7.7 2035.0837 FEB 179.8 148.5 88.2 18.9 13.9 7.6 2035.1670 MAR 176.9 147.7 89.8 18.9 14.0 7.5 2035.2503 APR 178.6 147.5 90.9 19.5 13.9 7.2 2035.3337 MAY 178.2 147.8 93.0 20.4 14.0 7.1 2035.4170 JUN 175.8 148.2 94.3 22.0 14.4 7.1 2035.5003 JUL 173.7 148.2 95.7 23.4 14.7 7.1 2035.5837 AUG 172.3 148.0 96.0 24.0 14.9 7.3 2035.6670 SEP 171.0 147.6 95.6 25.1 15.1 7.3 2035.7503 OCT 169.2 147.2 95.5 25.7 15.3 7.0 2035.8337 NOV 165.4 147.0 97.0 24.9 15.3 7.1 2035.9170 DEC 162.4 146.6 97.8 24.8 15.3 6.7 2036.0003 JAN 159.9 145.8 97.3 24.0 15.3 6.3 2036.0837 FEB 157.8 144.6 96.5 22.2 15.3 6.1 2036.1670 MAR 155.7 143.1 96.4 22.5 15.5 6.3 2036.2503 APR 155.3 141.4 96.9 23.2 15.7 6.5 2036.3337 MAY 155.2 140.0 96.4 23.2 15.7 6.7 2036.4170 JUN 153.7 138.7 95.7 22.7 15.7 7.1 2036.5003 JUL 150.5 137.2 96.3 22.0 15.6 7.6 2036.5837 AUG 146.7 135.5 97.2 21.9 15.7 7.7 2036.6670 SEP 143.8 133.5 96.3 22.7 15.9 8.1 2036.7503 OCT 140.4 131.8 94.6 23.6 16.2 8.7 2036.8337 NOV 137.4 130.4 93.8 23.8 16.4 8.9 2036.9170 DEC 136.7 129.2 93.6 23.8 16.6 9.3 2037.0003 JAN 136.0 127.5 91.8 23.8 16.6 9.7 2037.0837 FEB 134.8 125.7 88.4 23.4 16.6 10.1 2037.1670 MAR 133.8 124.4 88.0 22.5 16.5 10.5 2037.2503 APR 134.1 123.3 88.7 22.7 16.4 10.7 2037.3337 MAY 132.8 121.9 87.3 22.9 16.5 11.5 2037.4170 JUN 130.7 120.3 86.3 23.0 16.6 11.7 2037.5003 JUL 129.7 118.5 85.7 22.4 16.7 11.9 2037.5837 AUG 129.1 116.7 84.9 21.5 16.5 11.9 2037.6670 SEP 126.6 115.0 83.7 21.2 16.3 11.7 2037.7503 OCT 125.2 113.1 82.7 21.7 16.1 11.4 2037.8337 NOV 124.7 111.2 82.3 21.7 16.1 11.5 2037.9170 DEC 123.6 109.6 82.2 22.1 16.1 11.4 2038.0003 JAN 122.1 108.0 82.0 22.5 16.2 11.2 2038.0837 FEB 120.1 106.4 81.0 22.3 16.2 11.0 2038.1670 MAR 118.3 104.8 80.6 22.3 16.0 10.8 2038.2503 APR 116.2 103.4 80.6 22.7 15.8 10.7 2038.3337 MAY 114.3 101.8 80.0 22.9 15.5 10.6 2038.4170 JUN 111.1 100.2 79.1 23.4 15.3 10.3 2038.5003 JUL 109.5 98.7 77.7 24.0 15.0 10.1 2038.5837 AUG 107.9 97.5 75.7 24.7 14.9 10.1 2038.6670 SEP 106.4 96.3 74.6 25.3 14.8 10.1 2038.7503 OCT 104.4 95.2 74.1 25.4 14.8 10.5 2038.8337 NOV 103.0 94.3 73.8 25.3 14.7 10.4 2038.9170 DEC 102.0 93.3 73.5 24.8 14.5 10.2 2039.0003 JAN 100.5 92.1 73.1 23.9 14.3 10.0 2039.0837 FEB 98.9 91.0 72.7 23.0 14.1 9.4 2039.1670 MAR 98.2 90.0 72.0 22.5 14.2 8.8 2039.2503 APR 97.9 89.0 71.4 22.1 14.2 8.1 2039.3337 MAY 97.5 87.8 71.1 21.8 14.3 7.5 2039.4170 JUN 97.0 86.8 70.8 21.4 14.5 7.4 2039.5003 JUL 95.7 85.9 70.5 20.8 14.4 7.7 2039.5837 AUG 94.8 85.1 70.6 20.0 14.3 8.1 2039.6670 SEP 93.0 84.1 70.4 20.0 14.1 8.5 2039.7503 OCT 90.8 83.0 69.9 20.2 13.9 8.5 2039.8337 NOV 89.4 82.0 69.6 19.8 13.7 8.5 2039.9170 DEC 88.2 81.3 69.5 19.4 13.6 8.4 2040.0003 JAN 86.7 80.6 69.5 18.9 13.6 8.4 2040.0837 FEB 85.9 80.0 69.3 18.2 13.6 8.1 2040.1670 MAR 85.2 79.2 69.2 17.3 13.5 7.7 2040.2503 APR 83.9 78.5 68.8 17.3 13.3 7.1 2040.3337 MAY 82.8 77.8 68.6 17.4 13.2 6.8 2040.4170 JUN 81.8 77.2 68.4 17.5 13.1 6.6 2040.5003 JUL 81.2 76.6 68.4 17.5 12.9 6.5 2040.5837 AUG 80.7 76.1 68.5 17.7 12.9 6.6 2040.6670 SEP 80.5 75.6 68.5 18.0 12.7 6.5 2040.7503 OCT 79.2 75.1 68.5 17.9 12.6 6.4 2040.8337 NOV 77.9 74.6 68.4 17.6 12.3 6.4 2040.9170 DEC 77.2 73.9 68.3 17.3 12.0 6.2 2041.0003 JAN 76.7 73.2 68.1 16.3 11.7 6.1 2041.0837 FEB 75.8 72.6 67.8 14.9 11.2 6.0 2041.1670 MAR 75.3 72.1 67.7 13.8 10.9 6.1 2041.2503 APR 74.4 71.8 67.6 13.9 10.5 6.2 2041.3337 MAY 73.3 71.5 67.5 13.6 10.2 6.2 2041.4170 JUN 73.2 71.1 67.3 13.2 9.8 6.0 2041.5003 JUL 72.4 70.8 67.1 12.9 9.5 5.9 2041.5837 AUG 71.7 70.5 67.1 12.6 9.3 5.8 2041.6670 SEP 71.6 70.2 67.0 11.9 9.1 5.7 2041.7503 OCT 71.8 70.0 67.0 11.4 8.9 5.2