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% 2020.5003 JUL 11.0 9.0 6.3 5.7 5.2 5.0 2020.5837 AUG 14.9 10.3 5.4 6.1 5.2 4.8 2020.6670 SEP 20.1 11.4 5.1 6.2 5.2 4.6 2020.7503 OCT 23.9 12.5 5.2 6.3 5.4 4.7 2020.8337 NOV 27.2 13.6 4.2 7.0 5.6 4.7 2020.9170 DEC 31.2 15.2 3.6 7.4 5.7 4.4 2021.0003 JAN 34.8 17.1 2.7 7.5 5.7 4.0 2021.0837 FEB 38.3 18.9 1.1 8.0 5.7 3.7 2021.1670 MAR 43.6 21.3 0.0 8.6 5.7 3.6 2021.2503 APR 51.2 24.2 0.0 9.3 5.7 3.2 2021.3337 MAY 59.9 26.9 0.0 10.4 6.0 3.0 2021.4170 JUN 70.0 29.6 0.0 11.3 6.2 3.0 2021.5003 JUL 80.1 33.2 1.1 11.5 6.4 3.0 2021.5837 AUG 89.6 37.6 2.7 11.5 6.6 3.0 2021.6670 SEP 98.6 42.2 3.3 11.0 6.5 3.0 2021.7503 OCT 107.7 47.0 6.3 10.3 6.5 3.2 2021.8337 NOV 118.5 51.5 10.5 9.8 6.4 3.4 2021.9170 DEC 130.3 55.8 13.3 9.3 6.4 3.4 2022.0003 JAN 141.0 60.8 15.7 9.2 6.6 3.8 2022.0837 FEB 149.9 65.4 16.9 9.6 6.9 4.6 2022.1670 MAR 160.7 69.5 17.5 10.0 7.3 5.1 2022.2503 APR 172.0 74.1 19.2 9.9 7.7 5.3 2022.3337 MAY 178.9 78.6 20.8 10.0 7.9 5.4 2022.4170 JUN 182.7 83.2 23.1 10.6 8.1 4.9 2022.5003 JUL 187.6 87.4 25.3 11.3 8.3 4.6 2022.5837 AUG 192.0 90.1 25.1 11.4 8.5 4.5 2022.6670 SEP 197.9 92.8 25.2 12.1 8.9 4.7 2022.7503 OCT 206.4 96.0 28.1 13.0 9.3 5.0 2022.8337 NOV 213.8 99.3 30.8 13.7 9.5 4.7 2022.9170 DEC 218.7 103.4 33.1 14.1 9.6 4.4 2023.0003 JAN 225.8 107.8 37.8 14.3 10.0 4.2 2023.0837 FEB 233.6 111.5 43.9 14.9 10.3 4.0 2023.1670 MAR 238.5 114.3 45.8 15.2 10.3 3.9 2023.2503 APR 242.5 116.5 46.5 15.7 10.4 4.0 2023.3337 MAY 246.9 118.4 46.1 16.7 10.4 4.0 2023.4170 JUN 250.3 120.4 45.3 16.9 10.4 4.0 2023.5003 JUL 252.8 122.6 45.9 16.3 10.5 4.4 2023.5837 AUG 254.8 124.7 48.2 16.0 10.6 4.9 2023.6670 SEP 257.2 127.1 50.2 15.5 10.6 5.2 2023.7503 OCT 256.9 128.5 51.9 14.9 10.3 5.1 2023.8337 NOV 256.3 130.0 54.7 14.8 10.4 5.3 2023.9170 DEC 257.8 131.1 56.2 14.7 10.4 5.5 2024.0003 JAN 257.5 131.0 56.6 13.9 10.2 5.2 2024.0837 FEB 252.9 131.2 57.0 13.1 10.1 5.5 2024.1670 MAR 247.8 132.1 58.2 12.3 9.6 5.6 2024.2503 APR 243.2 133.6 61.4 12.2 9.1 5.4 2024.3337 MAY 240.0 134.6 64.1 12.6 9.0 5.2 2024.4170 JUN 238.5 134.9 65.0 13.7 9.0 4.9 2024.5003 JUL 237.9 135.5 65.9 14.6 9.0 4.8 2024.5837 AUG 236.4 136.6 68.2 15.1 9.1 5.2 2024.6670 SEP 234.4 137.2 70.5 15.8 9.1 5.2 2024.7503 OCT 233.6 137.2 69.8 15.9 9.0 5.1 2024.8337 NOV 231.7 136.6 68.3 15.4 9.2 5.3 2024.9170 DEC 231.6 136.0 67.5 15.2 9.1 5.1 2025.0003 JAN 229.9 135.7 68.8 14.2 9.0 5.8 2025.0837 FEB 225.6 134.5 70.0 13.2 9.0 5.8 2025.1670 MAR 220.6 131.8 70.4 13.2 9.3 6.4 2025.2503 APR 216.8 129.3 70.4 13.9 9.6 6.5 2025.3337 MAY 212.2 127.2 67.8 14.1 9.8 6.7 2025.4170 JUN 205.9 125.2 65.6 14.8 10.2 6.6 2025.5003 JUL 200.9 122.5 64.4 15.3 10.4 6.9 2025.5837 AUG 196.4 119.8 62.0 15.2 10.2 6.7 2025.6670 SEP 192.1 118.0 60.4 15.5 10.3 6.5 2025.7503 OCT 188.8 117.0 60.9 16.1 10.6 6.6 2025.8337 NOV 183.6 115.5 61.3 16.0 10.6 6.5 2025.9170 DEC 179.5 112.9 56.8 15.3 10.7 6.3 2026.0003 JAN 177.8 110.6 55.0 14.9 10.8 6.2 2026.0837 FEB 173.6 108.6 54.7 15.0 11.0 6.2 2026.1670 MAR 167.6 106.2 51.4 14.3 11.4 6.7 2026.2503 APR 162.5 103.8 47.9 14.5 11.8 7.2 2026.3337 MAY 158.1 101.5 45.9 15.2 12.1 8.1 2026.4170 JUN 152.6 99.1 44.2 15.6 12.4 8.2 2026.5003 JUL 147.4 96.7 41.9 15.4 12.6 8.6 2026.5837 AUG 143.1 94.5 39.7 16.1 12.8 9.2 2026.6670 SEP 135.1 91.9 38.5 17.4 12.9 9.4 2026.7503 OCT 129.8 88.8 37.8 18.1 12.9 9.6 2026.8337 NOV 128.2 85.4 36.8 18.5 13.1 9.9 2026.9170 DEC 125.9 81.8 34.8 18.5 13.4 9.9 2027.0003 JAN 121.1 78.7 33.0 18.9 13.5 9.6 2027.0837 FEB 114.6 76.4 33.0 18.7 13.4 9.0 2027.1670 MAR 108.9 74.1 30.3 18.8 13.3 8.8 2027.2503 APR 110.3 72.2 26.6 19.2 13.2 8.8 2027.3337 MAY 111.5 70.4 23.4 19.5 13.0 8.4 2027.4170 JUN 112.6 68.8 21.6 19.9 12.6 7.3 2027.5003 JUL 111.2 66.1 19.3 20.4 12.2 6.4 2027.5837 AUG 109.7 63.6 17.2 20.9 11.9 6.4 2027.6670 SEP 107.4 61.7 15.8 21.3 11.8 6.4 2027.7503 OCT 103.6 59.4 14.0 21.6 11.9 6.4 2027.8337 NOV 99.6 57.6 12.8 21.4 11.6 6.3 2027.9170 DEC 97.0 55.8 11.4 20.7 11.3 6.3 2028.0003 JAN 96.8 54.5 10.7 19.8 11.2 6.5 2028.0837 FEB 96.9 53.4 10.5 19.1 11.1 6.0 2028.1670 MAR 94.4 52.1 10.1 18.9 11.4 5.7 2028.2503 APR 90.8 50.7 10.7 18.6 11.5 5.1 2028.3337 MAY 85.8 48.6 11.0 18.4 11.7 4.6 2028.4170 JUN 81.7 46.7 10.3 18.2 12.0 4.6 2028.5003 JUL 82.4 45.8 10.6 17.8 12.1 5.1 2028.5837 AUG 81.0 44.7 11.4 18.1 12.0 5.6 2028.6670 SEP 75.9 42.2 11.0 18.3 11.9 5.9 2028.7503 OCT 71.3 39.5 10.1 18.4 11.7 5.9 2028.8337 NOV 68.6 37.7 9.2 18.2 11.7 6.1 2028.9170 DEC 67.6 35.8 8.9 18.1 11.9 6.4 2029.0003 JAN 64.3 33.6 8.3 17.8 12.2 6.8 2029.0837 FEB 59.4 31.5 7.5 17.3 12.4 7.0 2029.1670 MAR 55.6 29.6 6.2 16.4 12.4 7.1 2029.2503 APR 53.8 27.7 4.9 16.5 12.1 6.8 2029.3337 MAY 52.2 26.0 4.6 16.5 11.8 6.7 2029.4170 JUN 50.1 24.8 4.3 16.5 11.6 6.3 2029.5003 JUL 47.7 23.8 4.0 16.6 11.5 5.8 2029.5837 AUG 46.2 22.8 3.5 17.1 11.7 5.8 2029.6670 SEP 44.3 21.9 2.7 17.5 11.7 6.1 2029.7503 OCT 41.5 20.9 1.9 17.4 11.6 6.5 2029.8337 NOV 38.2 20.2 1.7 17.1 11.5 6.6 2029.9170 DEC 35.0 19.0 1.8 16.8 11.2 6.5 2030.0003 JAN 33.2 17.5 1.3 15.7 10.7 6.4 2030.0837 FEB 31.7 16.1 0.8 14.2 10.1 6.1 2030.1670 MAR 31.0 14.9 0.5 12.8 9.6 5.9 2030.2503 APR 30.8 14.2 0.6 12.9 9.3 5.7 2030.3337 MAY 30.2 13.1 0.6 12.6 8.9 5.6 2030.4170 JUN 29.1 11.9 0.4 12.2 8.6 5.5 2030.5003 JUL 26.8 10.9 0.2 12.1 8.5 5.4 2030.5837 AUG 24.2 10.2 0.1 11.8 8.3 5.1 2030.6670 SEP 21.8 9.5 0.0 11.1 8.1 4.6 2030.7503 OCT 20.2 8.8 0.0 10.6 7.9 4.1 2030.8337 NOV 17.8 8.2 0.0 10.4 7.7 3.8 2030.9170 DEC 17.9 8.3 0.0 10.5 7.8 3.9 2031.0003 JAN 18.9 9.0 0.7 10.7 7.9 3.7 2031.0837 FEB 20.8 10.2 1.3 11.1 8.1 3.8 2031.1670 MAR 22.6 11.5 1.7 11.3 8.3 3.8 2031.2503 APR 25.2 12.5 2.3 11.5 8.5 3.5 2031.3337 MAY 28.1 13.8 2.5 11.7 8.6 3.4 2031.4170 JUN 32.8 15.4 3.2 11.9 8.8 3.4 2031.5003 JUL 36.4 17.2 4.4 12.0 8.9 3.3 2031.5837 AUG 40.2 19.1 5.0 12.4 9.2 3.3 2031.6670 SEP 45.7 21.3 5.6 12.8 9.5 3.4 2031.7503 OCT 52.7 23.7 6.1 13.2 9.9 3.7 2031.8337 NOV 63.1 26.6 6.1 13.8 10.3 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