TABLE 4 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 25 WITH A MEAN CYCLE GIVEN FOR CYCLE 26 TIME SUNSPOT NUMBERS GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2025.7503 OCT 116.8 111.4 107.2 16.3 15.8 14.9 2025.8337 NOV 121.9 109.5 100.0 17.0 16.0 14.6 2025.9170 DEC 125.6 107.0 92.9 17.4 16.2 14.3 2026.0003 JAN 128.3 104.5 86.2 17.8 16.2 14.1 2026.0837 FEB 128.1 102.5 82.1 18.2 16.2 13.9 2026.1670 MAR 126.0 100.9 79.7 18.6 16.2 13.6 2026.2503 APR 123.2 99.4 77.5 19.1 16.1 13.7 2026.3337 MAY 123.4 97.9 73.5 19.8 16.2 13.5 2026.4170 JUN 124.6 96.0 68.4 20.3 16.4 12.5 2026.5003 JUL 122.8 93.7 63.7 20.5 16.5 11.5 2026.5837 AUG 120.4 91.4 61.0 20.9 16.4 11.4 2026.6670 SEP 121.6 88.8 59.6 21.7 16.2 11.6 2026.7503 OCT 122.3 85.9 59.2 22.1 16.1 12.1 2026.8337 NOV 122.1 83.4 59.2 21.9 16.0 12.2 2026.9170 DEC 120.1 80.7 57.3 22.1 16.1 11.7 2027.0003 JAN 115.2 78.2 55.2 22.5 16.2 11.3 2027.0837 FEB 110.8 76.2 53.2 22.3 16.2 11.2 2027.1670 MAR 111.0 73.9 49.6 22.3 16.0 10.9 2027.2503 APR 112.0 71.4 43.9 22.7 15.8 10.9 2027.3337 MAY 113.8 69.3 38.7 22.9 15.5 11.1 2027.4170 JUN 114.8 67.3 35.1 23.4 15.3 10.8 2027.5003 JUL 113.4 65.0 32.7 24.0 15.0 10.3 2027.5837 AUG 111.9 62.5 31.0 24.7 14.9 10.3 2027.6670 SEP 109.5 60.3 29.5 25.3 14.8 10.3 2027.7503 OCT 105.8 58.3 28.0 25.4 14.8 10.4 2027.8337 NOV 101.8 56.3 25.9 25.3 14.6 10.4 2027.9170 DEC 98.5 54.0 22.6 24.8 14.5 10.4 2028.0003 JAN 97.8 52.0 20.8 23.9 14.3 9.8 2028.0837 FEB 97.7 50.5 19.8 23.0 14.1 9.4 2028.1670 MAR 95.0 48.9 19.0 22.5 14.2 9.1 2028.2503 APR 91.3 47.0 19.1 22.1 14.3 8.7 2028.3337 MAY 86.3 44.9 19.6 21.8 14.4 8.4 2028.4170 JUN 81.4 43.2 19.7 21.3 14.5 8.5 2028.5003 JUL 79.2 41.9 18.8 20.7 14.5 8.5 2028.5837 AUG 77.9 40.4 17.4 19.9 14.3 8.3 2028.6670 SEP 75.1 38.6 16.4 19.4 14.2 8.1 2028.7503 OCT 71.4 36.8 16.6 19.6 14.0 7.8 2028.8337 NOV 69.6 35.8 17.0 19.4 13.8 7.8 2028.9170 DEC 68.3 34.8 13.9 19.0 13.7 7.8 2029.0003 JAN 65.1 33.3 10.5 18.4 13.6 7.6 2029.0837 FEB 61.1 31.8 8.0 17.8 13.6 7.4 2029.1670 MAR 57.3 30.2 6.3 17.0 13.5 7.3 2029.2503 APR 55.8 28.7 4.7 17.3 13.3 7.0 2029.3337 MAY 53.9 27.1 3.5 17.5 13.2 7.1 2029.4170 JUN 52.2 25.8 3.4 17.7 13.1 7.1 2029.5003 JUL 50.7 24.6 4.0 17.6 12.9 6.8 2029.5837 AUG 48.5 23.3 4.0 17.7 12.8 6.7 2029.6670 SEP 45.3 21.9 3.4 18.0 12.7 6.6 2029.7503 OCT 42.4 20.6 3.1 17.9 12.6 6.4 2029.8337 NOV 38.2 19.5 3.6 17.7 12.3 6.2 2029.9170 DEC 33.4 18.1 4.0 17.4 12.0 6.0 2030.0003 JAN 31.7 16.4 4.2 16.3 11.7 6.0 2030.0837 FEB 29.9 15.0 4.2 14.9 11.2 5.9 2030.1670 MAR 29.6 13.8 3.6 13.7 10.9 5.8 2030.2503 APR 29.4 12.8 3.2 13.7 10.6 5.8 2030.3337 MAY 28.9 11.9 3.5 13.4 10.2 5.8 2030.4170 JUN 28.3 11.2 3.5 13.0 9.9 5.5 2030.5003 JUL 26.0 10.5 2.9 12.6 9.6 5.3 2030.5837 AUG 23.0 9.7 2.6 12.2 9.4 5.2 2030.6670 SEP 21.3 9.0 1.8 11.5 9.2 5.2 2030.7503 OCT 19.8 8.3 0.8 11.3 8.9 5.2 2030.8337 NOV 17.4 7.6 0.0 11.1 8.7 5.1 2030.9170 DEC 17.5 7.8 0.0 11.1 8.7 5.0 2031.0003 JAN 18.5 8.6 0.7 11.3 8.8 4.8 2031.0837 FEB 20.4 9.8 1.3 11.6 8.9 4.8 2031.1670 MAR 22.3 11.1 1.7 11.7 9.0 4.6 2031.2503 APR 25.0 12.2 2.3 11.9 9.1 4.3 2031.3337 MAY 27.9 13.5 2.5 12.0 9.1 4.0 2031.4170 JUN 32.6 15.2 3.2 12.1 9.2 3.9 2031.5003 JUL 36.3 17.0 4.4 12.2 9.3 3.8 2031.5837 AUG 40.0 19.0 5.0 12.6 9.4 3.6 2031.6670 SEP 45.6 21.2 5.6 12.9 9.7 3.6 2031.7503 OCT 52.7 23.6 6.1 13.3 10.0 3.8 2031.8337 NOV 63.1 26.6 6.1 13.8 10.4 4.2 2031.9170 DEC 71.9 29.9 6.3 14.6 10.6 4.5 2032.0003 JAN 78.8 33.1 7.3 15.7 10.9 4.7 2032.0837 FEB 88.8 36.7 7.3 16.1 11.1 4.8 2032.1670 MAR 99.7 40.7 7.3 16.3 11.3 5.0 2032.2503 APR 109.4 44.7 8.0 16.9 11.4 5.1 2032.3337 MAY 121.3 49.1 8.2 18.0 11.6 5.3 2032.4170 JUN 135.7 53.9 8.9 18.9 11.9 5.4 2032.5003 JUL 145.7 58.8 10.0 19.1 12.1 5.6 2032.5837 AUG 152.6 64.1 11.7 19.2 12.3 5.8 2032.6670 SEP 159.7 69.6 13.3 19.0 12.6 6.0 2032.7503 OCT 167.7 74.9 15.6 18.6 12.7 6.1 2032.8337 NOV 176.8 80.0 16.9 18.5 12.7 6.1 2032.9170 DEC 186.4 85.3 17.0 18.9 12.8 6.1 2033.0003 JAN 195.5 91.2 19.1 18.8 12.9 6.3 2033.0837 FEB 203.4 97.0 20.9 17.8 13.0 6.5 2033.1670 MAR 211.7 102.6 22.7 17.9 13.2 6.7 2033.2503 APR 216.9 108.0 24.6 18.4 13.4 7.1 2033.3337 MAY 223.4 113.7 25.4 19.1 13.7 7.0 2033.4170 JUN 224.9 118.9 26.5 19.6 14.2 7.0 2033.5003 JUL 225.7 123.4 27.6 20.3 14.5 7.1 2033.5837 AUG 231.1 127.1 28.4 20.3 14.5 7.2 2033.6670 SEP 233.8 130.6 29.3 20.3 14.6 7.7 2033.7503 OCT 236.3 134.3 29.4 20.5 14.7 8.1 2033.8337 NOV 239.2 137.7 28.9 20.8 14.8 8.0 2033.9170 DEC 241.6 141.1 28.5 21.2 14.8 8.0 2034.0003 JAN 248.2 144.4 29.4 21.3 14.6 8.4 2034.0837 FEB 255.6 147.5 30.6 21.4 14.6 8.6 2034.1670 MAR 260.5 150.2 32.8 21.6 14.6 8.4 2034.2503 APR 264.8 153.0 36.1 22.0 14.5 8.4 2034.3337 MAY 269.5 155.4 38.1 22.7 14.4 8.6 2034.4170 JUN 272.7 157.2 40.4 22.4 14.1 8.6 2034.5003 JUL 274.4 158.0 44.2 21.3 13.8 8.5 2034.5837 AUG 275.1 158.0 48.5 20.6 13.7 8.3 2034.6670 SEP 276.4 158.8 52.8 20.1 13.6 8.0 2034.7503 OCT 276.2 160.2 54.7 19.7 13.5 7.6 2034.8337 NOV 275.2 161.0 56.7 19.6 13.5 7.5 2034.9170 DEC 276.2 161.2 60.3 19.3 13.5 7.8 2035.0003 JAN 275.3 160.2 62.7 19.1 13.7 7.7 2035.0837 FEB 269.5 158.5 66.2 18.9 13.9 7.6 2035.1670 MAR 263.0 157.1 68.8 18.9 14.0 7.5 2035.2503 APR 257.3 156.7 71.6 19.5 13.9 7.2 2035.3337 MAY 253.6 156.9 73.6 20.4 14.0 7.1 2035.4170 JUN 251.7 156.6 73.3 22.0 14.4 7.1 2035.5003 JUL 249.8 156.0 72.5 23.4 14.7 7.1 2035.5837 AUG 248.7 155.6 73.6 24.0 14.9 7.3 2035.6670 SEP 246.7 155.0 76.8 25.1 15.1 7.3 2035.7503 OCT 244.9 154.3 76.9 25.7 15.3 7.0 2035.8337 NOV 242.7 153.3 75.2 24.9 15.3 7.1 2035.9170 DEC 241.9 152.0 74.2 24.8 15.3 6.7 2036.0003 JAN 239.5 150.6 75.1 24.0 15.3 6.3 2036.0837 FEB 234.9 148.4 75.8 22.2 15.3 6.1 2036.1670 MAR 230.5 145.4 73.9 22.5 15.5 6.3 2036.2503 APR 226.5 142.7 73.2 23.2 15.7 6.5 2036.3337 MAY 222.0 140.7 74.9 23.2 15.7 6.7 2036.4170 JUN 216.0 138.6 76.5 22.7 15.7 7.1 2036.5003 JUL 210.7 135.7 74.5 22.0 15.6 7.6 2036.5837 AUG 205.8 132.7 71.2 21.9 15.7 7.7 2036.6670 SEP 202.0 130.3 69.5 22.7 15.9 8.1 2036.7503 OCT 200.2 128.2 68.9 23.6 16.2 8.7 2036.8337 NOV 194.9 125.5 65.8 23.8 16.4 8.9 2036.9170 DEC 191.9 122.7 58.8 23.8 16.6 9.3 2037.0003 JAN 189.9 119.8 57.2 23.8 16.6 9.7 2037.0837 FEB 185.1 117.3 59.1 23.4 16.6 10.1 2037.1670 MAR 179.7 115.3 57.6 22.5 16.5 10.5 2037.2503 APR 174.1 113.5 54.5 22.7 16.4 10.7 2037.3337 MAY 168.6 111.5 52.9 22.9 16.5 11.5 2037.4170 JUN 163.9 109.2 51.6 23.0 16.6 11.7 2037.5003 JUL 160.3 106.3 49.1 22.4 16.7 11.9 2037.5837 AUG 154.9 103.4 46.5 21.5 16.5 11.9 2037.6670 SEP 146.1 100.2 45.0 21.2 16.3 11.7 2037.7503 OCT 138.4 96.7 44.3 21.7 16.1 11.4 2037.8337 NOV 136.9 93.7 44.5 21.7 16.1 11.5 2037.9170 DEC 135.5 90.9 43.0 22.1 16.1 11.4 2038.0003 JAN 131.3 88.4 40.6 22.5 16.2 11.2 2038.0837 FEB 126.7 86.0 40.9 22.3 16.2 11.0 2038.1670 MAR 121.9 83.3 39.8 22.3 16.0 10.8 2038.2503 APR 116.7 80.6 37.9 22.7 15.8 10.7 2038.3337 MAY 115.8 78.0 36.5 22.9 15.5 10.6 2038.4170 JUN 116.7 75.4 34.0 23.4 15.3 10.3 2038.5003 JUL 115.2 72.7 31.6 24.0 15.0 10.1 2038.5837 AUG 113.7 70.1 27.9 24.7 14.9 10.1 2038.6670 SEP 111.2 67.9 24.9 25.3 14.8 10.1 2038.7503 OCT 107.6 65.9 22.9 25.4 14.8 10.5 2038.8337 NOV 103.7 64.0 20.0 25.3 14.7 10.4 2038.9170 DEC 100.4 61.7 17.6 24.8 14.5 10.2 2039.0003 JAN 99.3 59.5 16.1 23.9 14.3 10.0 2039.0837 FEB 98.2 57.6 14.9 23.0 14.1 9.4 2039.1670 MAR 95.1 55.6 13.6 22.5 14.2 8.8 2039.2503 APR 91.4 53.5 13.5 22.1 14.2 8.1 2039.3337 MAY 86.4 51.3 13.6 21.8 14.3 7.5 2039.4170 JUN 84.7 49.5 13.1 21.4 14.5 7.4 2039.5003 JUL 85.0 48.0 12.9 20.8 14.4 7.7 2039.5837 AUG 82.2 46.4 12.6 20.0 14.3 8.1 2039.6670 SEP 77.6 44.3 12.0 20.0 14.1 8.5 2039.7503 OCT 73.8 42.1 11.1 20.2 13.9 8.5 2039.8337 NOV 70.0 40.7 11.0 19.8 13.7 8.5 2039.9170 DEC 68.3 39.4 10.3 19.4 13.6 8.4 2040.0003 JAN 65.8 37.7 9.2 18.9 13.6 8.4 2040.0837 FEB 64.4 36.0 8.8 18.2 13.6 8.1 2040.1670 MAR 62.8 34.3 7.4 17.3 13.5 7.7 2040.2503 APR 61.9 32.8 6.0 17.3 13.3 7.1 2040.3337 MAY 60.4 31.1 5.9 17.4 13.2 6.8 2040.4170 JUN 58.5 29.7 5.8 17.5 13.1 6.6 2040.5003 JUL 56.4 28.3 5.6 17.5 12.9 6.5 2040.5837 AUG 54.1 26.9 5.4 17.7 12.9 6.6 2040.6670 SEP 51.2 25.4 4.3 18.0 12.7 6.5 2040.7503 OCT 48.1 24.0 3.3 17.9 12.6 6.4 2040.8337 NOV 43.8 22.8 2.9 17.6 12.3 6.4 2040.9170 DEC 38.5 21.2 2.7 17.3 12.0 6.2 2041.0003 JAN 34.9 19.3 2.1 16.3 11.7 6.1 2041.0837 FEB 33.1 17.6 1.5 14.9 11.2 6.0 2041.1670 MAR 32.1 16.2 1.2 13.8 10.9 6.1 2041.2503 APR 31.6 15.0 1.1 13.9 10.5 6.2 2041.3337 MAY 31.0 14.0 1.0 13.6 10.2 6.2 2041.4170 JUN 30.2 13.1 0.8 13.2 9.8 6.0 2041.5003 JUL 27.9 12.2 0.6 12.9 9.5 5.9 2041.5837 AUG 25.2 11.4 0.3 12.6 9.3 5.8 2041.6670 SEP 23.3 10.6 0.1 11.9 9.1 5.7 2041.7503 OCT 21.6 9.8 0.0 11.4 8.9 5.2