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% 2021.8337 NOV 54.7 49.1 44.5 8.3 7.8 7.3 2021.9170 DEC 64.9 52.8 44.5 8.6 8.0 7.0 2022.0003 JAN 74.2 57.2 45.4 9.2 8.2 7.0 2022.0837 FEB 82.5 61.8 48.1 10.4 8.5 6.8 2022.1670 MAR 91.6 66.0 46.5 11.0 9.0 6.9 2022.2503 APR 102.4 70.4 45.8 11.8 9.5 7.1 2022.3337 MAY 113.5 75.1 46.1 12.8 9.8 7.4 2022.4170 JUN 124.2 80.1 47.0 13.0 10.1 7.7 2022.5003 JUL 134.1 84.4 47.8 12.8 10.3 7.2 2022.5837 AUG 141.9 87.4 48.8 12.6 10.3 6.9 2022.6670 SEP 148.8 90.1 49.9 13.0 10.5 6.8 2022.7503 OCT 157.8 93.3 46.9 13.7 10.7 6.7 2022.8337 NOV 169.9 96.5 43.7 14.3 10.8 6.3 2022.9170 DEC 180.6 100.3 40.7 14.6 10.9 5.9 2023.0003 JAN 189.8 104.0 37.8 14.5 11.1 5.4 2023.0837 FEB 195.8 107.1 36.6 14.2 11.2 5.1 2023.1670 MAR 201.0 110.3 36.7 14.4 11.2 4.9 2023.2503 APR 206.3 113.3 38.6 14.7 11.1 4.8 2023.3337 MAY 211.6 116.1 39.2 15.5 11.0 4.6 2023.4170 JUN 213.2 118.5 38.6 15.7 10.9 4.5 2023.5003 JUL 211.8 120.5 39.4 15.4 11.1 5.0 2023.5837 AUG 210.4 122.2 39.8 15.4 11.3 5.6 2023.6670 SEP 212.1 124.2 42.1 15.2 11.3 6.1 2023.7503 OCT 214.1 125.9 45.4 14.8 11.2 6.3 2023.8337 NOV 215.7 127.5 47.4 14.8 11.3 6.5 2023.9170 DEC 214.7 128.6 49.0 14.5 11.3 6.6 2024.0003 JAN 210.5 128.4 48.5 14.8 11.2 6.6 2024.0837 FEB 204.8 128.0 49.9 15.3 11.3 7.2 2024.1670 MAR 202.3 128.3 52.2 15.2 11.1 7.5 2024.2503 APR 201.5 129.7 53.8 14.6 10.7 7.4 2024.3337 MAY 199.0 131.1 53.8 14.6 10.6 7.4 2024.4170 JUN 195.8 131.7 53.1 15.8 10.7 7.2 2024.5003 JUL 196.8 132.0 51.4 16.9 10.8 7.3 2024.5837 AUG 198.6 132.9 49.6 17.5 11.0 7.7 2024.6670 SEP 199.9 134.0 49.8 18.5 11.1 7.0 2024.7503 OCT 200.4 134.4 48.7 18.7 11.1 6.5 2024.8337 NOV 198.1 133.8 47.4 18.1 11.3 6.6 2024.9170 DEC 198.0 133.3 47.0 18.1 11.3 6.6 2025.0003 JAN 197.6 132.8 48.1 17.4 11.3 6.3 2025.0837 FEB 195.6 131.5 48.3 15.6 11.4 6.1 2025.1670 MAR 193.9 129.7 48.4 15.0 11.6 6.2 2025.2503 APR 192.5 128.1 49.5 15.4 12.0 6.5 2025.3337 MAY 190.1 126.9 50.6 15.8 12.3 6.9 2025.4170 JUN 186.1 125.9 52.4 16.7 12.5 7.5 2025.5003 JUL 184.0 123.9 54.1 17.5 12.6 7.8 2025.5837 AUG 184.7 121.9 54.0 18.3 12.5 7.6 2025.6670 SEP 188.2 120.5 54.2 18.7 12.5 7.7 2025.7503 OCT 188.6 119.3 55.4 19.1 12.8 8.2 2025.8337 NOV 185.0 117.8 56.9 19.1 12.8 8.0 2025.9170 DEC 182.1 115.5 53.9 18.5 12.9 7.9 2026.0003 JAN 180.4 113.0 52.3 17.6 12.9 7.8 2026.0837 FEB 176.6 110.9 52.2 16.3 13.0 7.7 2026.1670 MAR 171.7 109.1 49.4 16.8 13.3 8.1 2026.2503 APR 166.4 107.4 46.5 17.1 13.6 8.5 2026.3337 MAY 161.1 105.7 45.1 17.7 13.8 9.4 2026.4170 JUN 157.2 103.7 44.4 18.0 14.0 10.0 2026.5003 JUL 154.4 101.5 42.7 17.9 14.2 10.2 2026.5837 AUG 149.3 99.0 40.6 19.2 14.3 10.5 2026.6670 SEP 140.7 96.1 39.6 20.3 14.4 10.8 2026.7503 OCT 133.8 93.2 39.7 20.9 14.5 11.2 2026.8337 NOV 131.8 90.4 40.1 21.0 14.6 11.6 2026.9170 DEC 130.0 87.3 38.6 20.7 14.7 11.1 2027.0003 JAN 125.9 84.8 37.4 20.0 14.7 10.5 2027.0837 FEB 122.8 83.1 38.9 19.2 14.6 9.8 2027.1670 MAR 119.3 81.1 39.3 18.7 14.4 9.4 2027.2503 APR 115.2 79.1 39.0 18.9 14.1 8.9 2027.3337 MAY 116.2 76.9 36.4 18.8 13.7 8.3 2027.4170 JUN 117.0 74.7 33.3 19.0 13.3 7.1 2027.5003 JUL 115.6 71.8 30.6 19.1 12.8 5.8 2027.5837 AUG 114.0 69.2 27.2 19.2 12.3 5.3 2027.6670 SEP 111.5 67.1 24.6 19.3 12.1 5.0 2027.7503 OCT 108.0 64.7 22.5 19.4 12.0 4.9 2027.8337 NOV 104.0 62.6 20.5 19.1 11.8 4.8 2027.9170 DEC 100.9 60.3 18.1 18.6 11.6 5.0 2028.0003 JAN 99.6 58.5 16.5 18.0 11.6 5.4 2028.0837 FEB 98.3 57.1 15.0 17.5 11.6 6.0 2028.1670 MAR 95.1 55.6 13.6 17.4 11.8 6.3 2028.2503 APR 91.2 54.0 13.5 17.3 12.0 6.1 2028.3337 MAY 86.2 51.8 13.7 17.4 12.3 5.6 2028.4170 JUN 85.1 50.0 13.0 17.5 12.6 5.7 2028.5003 JUL 85.7 49.0 12.5 18.2 12.7 6.1 2028.5837 AUG 83.1 47.9 11.9 18.6 12.7 6.7 2028.6670 SEP 78.4 45.7 11.4 18.9 12.7 7.1 2028.7503 OCT 74.1 43.2 11.2 19.0 12.5 7.1 2028.8337 NOV 69.9 41.2 11.1 18.8 12.5 7.2 2028.9170 DEC 68.3 39.4 10.3 18.6 12.6 7.4 2029.0003 JAN 65.9 37.3 9.2 18.3 12.8 7.6 2029.0837 FEB 63.8 35.2 8.6 17.6 12.9 7.7 2029.1670 MAR 61.8 33.2 7.1 16.9 12.9 7.8 2029.2503 APR 60.1 31.2 5.6 17.3 12.7 7.3 2029.3337 MAY 58.4 29.3 5.4 17.4 12.5 7.0 2029.4170 JUN 56.5 27.9 5.3 17.5 12.4 6.8 2029.5003 JUL 54.6 26.7 5.2 17.5 12.4 6.6 2029.5837 AUG 52.5 25.5 5.2 17.6 12.5 6.7 2029.6670 SEP 50.1 24.2 4.9 17.9 12.5 6.5 2029.7503 OCT 47.0 22.9 3.8 17.9 12.4 6.4 2029.8337 NOV 42.7 21.8 3.3 17.6 12.3 6.4 2029.9170 DEC 37.6 20.3 3.2 17.3 12.0 6.2 2030.0003 JAN 34.6 18.6 2.6 16.2 11.5 6.1 2030.0837 FEB 32.6 17.0 1.8 14.7 11.0 6.1 2030.1670 MAR 32.0 15.7 1.4 13.6 10.6 6.2 2030.2503 APR 31.6 14.8 1.2 13.6 10.2 6.3 2030.3337 MAY 30.9 13.8 1.1 13.3 9.7 6.3 2030.4170 JUN 30.1 12.7 1.0 12.9 9.4 6.1 2030.5003 JUL 27.7 11.7 1.0 12.6 9.2 6.0 2030.5837 AUG 24.6 10.8 0.8 12.3 9.0 5.9 2030.6670 SEP 22.6 10.0 0.6 11.5 8.7 5.3 2030.7503 OCT 21.1 9.3 0.5 11.0 8.5 4.8 2030.8337 NOV 18.8 8.6 0.5 10.8 8.2 4.4 2030.9170 DEC 18.8 8.7 0.4 10.8 8.2 4.5 2031.0003 JAN 19.7 9.4 1.1 11.1 8.3 4.3 2031.0837 FEB 21.5 10.5 1.7 11.4 8.5 4.3 2031.1670 MAR 23.2 11.7 2.0 11.5 8.7 4.2 2031.2503 APR 25.8 12.8 2.6 11.8 8.8 3.9 2031.3337 MAY 28.6 14.0 2.7 11.9 8.9 3.7 2031.4170 JUN 33.2 15.6 3.4 12.0 9.0 3.6 2031.5003 JUL 36.7 17.3 4.5 12.2 9.1 3.6 2031.5837 AUG 40.4 19.2 5.1 12.5 9.3 3.5 2031.6670 SEP 45.8 21.4 5.7 12.8 9.6 3.5 2031.7503 OCT 52.8 23.7 6.1 13.3 10.0 3.8 2031.8337 NOV 63.0 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 176.7 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 231.0 127.1 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 241.7 141.1 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 260.4 150.2 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 75.9 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 163.8 109.2 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 115.9 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 98.1 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 13.4 22.1 14.2 8.1 2039.3337 MAY 86.4 51.3 13.7 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