TABLE 3 ESTIMATES OF 13-MONTH SMOOTH SOLAR ACTIVITY FOR BALANCE OF CYCLE 24 WITH A MEAN CYCLE GIVEN FOR CYCLE 25 TIME 10.7 CM SOLAR FLUX (F10.7) GEOMAGNETIC INDEX (Ap) PERCENTILE PERCENTILE 95.0% 50% 5.0% 95.0% 50% 5.0% 2018.3337 MAY 70.9 70.3 69.5 8.1 7.5 6.4 2018.4170 JUN 71.2 70.1 68.6 8.7 7.6 6.0 2018.5003 JUL 71.7 70.0 68.2 9.2 7.8 6.3 2018.5837 AUG 71.9 69.8 67.5 9.7 7.9 6.1 2018.6670 SEP 72.5 69.6 67.5 10.2 7.9 6.1 2018.7503 OCT 72.6 69.7 67.1 10.5 8.0 6.4 2018.8337 NOV 73.2 69.8 66.7 10.7 8.1 6.1 2018.9170 DEC 73.4 69.7 66.6 10.9 8.1 6.0 2019.0003 JAN 73.1 69.6 66.3 10.6 8.2 6.0 2019.0837 FEB 72.7 69.3 66.1 10.0 8.3 6.1 2019.1670 MAR 72.6 69.2 66.0 10.4 8.5 6.4 2019.2503 APR 72.6 69.0 65.6 10.7 8.6 6.4 2019.3337 MAY 72.6 68.9 65.2 10.9 8.6 6.4 2019.4170 JUN 72.5 68.7 65.2 10.6 8.3 6.1 2019.5003 JUL 72.5 68.7 65.6 10.1 7.9 5.8 2019.5837 AUG 72.8 68.7 66.0 9.7 7.6 5.4 2019.6670 SEP 72.7 68.6 66.2 9.6 7.7 5.3 2019.7503 OCT 72.6 68.5 66.3 9.5 7.7 5.4 2019.8337 NOV 72.2 68.3 66.2 9.2 7.7 5.3 2019.9170 DEC 72.2 68.3 66.2 9.2 7.7 5.3 2020.0003 JAN 72.3 68.4 66.2 9.5 7.8 5.3 2020.0837 FEB 73.0 68.8 66.3 9.8 7.9 5.5 2020.1670 MAR 73.8 69.1 66.4 9.9 8.1 5.8 2020.2503 APR 74.6 69.5 66.5 10.1 8.2 5.9 2020.3337 MAY 75.7 69.9 66.6 10.2 8.2 5.9 2020.4170 JUN 77.2 70.5 66.7 10.3 8.3 5.7 2020.5003 JUL 78.6 71.1 66.9 10.4 8.4 5.6 2020.5837 AUG 80.0 71.7 67.0 10.7 8.6 5.4 2020.6670 SEP 82.3 72.6 67.1 11.0 8.9 5.3 2020.7503 OCT 85.3 73.5 67.2 11.4 9.3 5.5 2020.8337 NOV 90.0 74.8 67.5 11.9 9.6 5.9 2020.9170 DEC 94.4 76.2 67.6 12.7 9.9 6.2 2021.0003 JAN 97.8 77.6 67.6 13.9 10.2 6.0 2021.0837 FEB 102.9 79.4 67.6 14.3 10.4 6.0 2021.1670 MAR 108.8 81.4 67.6 14.5 10.5 5.9 2021.2503 APR 114.6 83.5 67.5 15.0 10.7 5.9 2021.3337 MAY 121.9 85.8 67.8 16.2 11.0 6.0 2021.4170 JUN 130.3 88.3 67.9 17.1 11.3 6.0 2021.5003 JUL 136.8 91.0 68.2 17.3 11.4 6.0 2021.5837 AUG 141.5 93.9 68.4 17.4 11.7 6.1 2021.6670 SEP 145.9 96.7 68.5 17.2 11.8 6.0 2021.7503 OCT 150.3 99.5 68.7 16.8 11.9 6.0 2021.8337 NOV 155.2 102.4 69.2 16.7 12.0 6.1 2021.9170 DEC 160.5 105.5 69.8 17.1 12.1 6.3 2022.0003 JAN 165.7 108.5 70.1 17.0 12.2 6.5 2022.0837 FEB 170.3 111.7 70.5 16.0 12.3 6.9 2022.1670 MAR 176.2 115.0 70.7 16.1 12.5 7.0 2022.2503 APR 183.7 118.2 71.4 16.7 12.7 7.1 2022.3337 MAY 188.6 121.4 72.2 17.3 12.9 7.4 2022.4170 JUN 191.2 124.2 72.6 17.8 13.4 7.8 2022.5003 JUL 193.8 126.6 73.4 18.5 13.7 7.9 2022.5837 AUG 196.8 128.9 74.0 18.5 13.8 7.9 2022.6670 SEP 201.4 131.1 74.3 18.5 13.9 8.2 2022.7503 OCT 207.5 133.6 74.8 18.7 13.9 8.4 2022.8337 NOV 211.6 136.2 75.1 19.0 14.1 8.9 2022.9170 DEC 214.4 138.7 75.3 19.4 14.1 9.5 2023.0003 JAN 218.9 140.8 75.3 19.5 14.0 10.0 2023.0837 FEB 223.3 142.8 75.3 19.6 13.8 9.7 2023.1670 MAR 225.3 144.5 75.4 19.8 13.8 9.6 2023.2503 APR 226.3 146.1 75.8 20.2 13.7 9.0 2023.3337 MAY 228.2 147.5 76.2 21.0 13.6 8.6 2023.4170 JUN 230.3 148.3 76.9 20.7 13.4 8.3 2023.5003 JUL 233.2 149.2 78.2 19.5 13.2 8.4 2023.5837 AUG 236.3 149.7 78.9 18.8 13.1 8.5 2023.6670 SEP 237.6 149.9 79.9 18.3 13.0 8.7 2023.7503 OCT 235.8 150.2 81.4 17.8 12.8 8.9 2023.8337 NOV 233.7 150.4 83.0 17.7 12.7 8.9 2023.9170 DEC 234.8 150.5 84.8 17.5 12.8 8.8 2024.0003 JAN 235.3 149.6 85.7 17.3 13.0 8.8 2024.0837 FEB 233.0 148.1 87.0 17.1 13.3 8.8 2024.1670 MAR 229.8 147.2 88.7 17.1 13.4 8.6 2024.2503 APR 226.3 146.8 90.0 17.7 13.3 8.2 2024.3337 MAY 224.6 146.9 92.2 18.6 13.4 8.6 2024.4170 JUN 224.9 147.3 93.4 20.2 13.8 9.0 2024.5003 JUL 225.2 147.5 94.7 21.6 14.0 9.1 2024.5837 AUG 224.0 147.1 95.0 22.2 14.2 9.3 2024.6670 SEP 222.4 146.5 94.6 23.3 14.4 9.4 2024.7503 OCT 222.0 146.0 94.7 23.8 14.6 9.6 2024.8337 NOV 222.0 145.7 96.1 23.1 14.6 9.8 2024.9170 DEC 221.6 145.6 97.0 23.0 14.6 10.1 2025.0003 JAN 220.6 144.8 96.4 22.1 14.6 10.2 2025.0837 FEB 218.4 143.6 95.7 20.3 14.5 10.2 2025.1670 MAR 215.2 142.0 95.6 20.6 14.6 10.4 2025.2503 APR 212.5 140.2 96.1 21.3 14.7 10.1 2025.3337 MAY 209.8 138.6 95.6 21.3 14.8 9.4 2025.4170 JUN 206.5 137.3 94.7 20.8 14.7 9.1 2025.5003 JUL 205.4 135.9 95.4 20.2 14.6 9.1 2025.5837 AUG 203.4 134.1 96.3 20.1 14.6 9.1 2025.6670 SEP 200.0 132.2 95.5 20.9 14.9 9.1 2025.7503 OCT 196.5 130.7 93.8 21.9 15.2 9.2 2025.8337 NOV 194.0 129.3 93.0 22.1 15.5 9.2 2025.9170 DEC 192.0 128.0 92.8 22.1 15.7 9.1 2026.0003 JAN 188.1 126.2 90.9 22.1 15.9 8.9 2026.0837 FEB 183.5 124.4 87.5 21.7 15.9 8.7 2026.1670 MAR 179.1 123.0 87.1 20.7 16.0 8.8 2026.2503 APR 175.3 122.0 87.9 20.9 15.9 9.0 2026.3337 MAY 173.0 120.8 86.5 21.2 16.1 9.7 2026.4170 JUN 171.1 119.5 85.5 21.3 16.4 10.2 2026.5003 JUL 166.8 117.8 84.9 20.7 16.5 10.4 2026.5837 AUG 160.4 115.8 84.1 19.8 16.4 10.5 2026.6670 SEP 154.5 114.0 82.8 19.4 16.1 10.6 2026.7503 OCT 150.9 112.1 81.8 19.9 15.8 10.8 2026.8337 NOV 148.5 110.2 81.4 19.9 15.6 11.6 2026.9170 DEC 146.1 108.5 81.4 20.3 15.7 11.4 2027.0003 JAN 143.1 107.1 81.2 20.8 15.7 11.2 2027.0837 FEB 140.0 105.5 80.2 20.5 15.5 11.4 2027.1670 MAR 136.5 103.9 79.8 20.6 15.3 11.1 2027.2503 APR 132.8 102.5 79.8 20.9 15.0 10.9 2027.3337 MAY 128.5 101.0 79.2 21.1 14.6 10.4 2027.4170 JUN 122.6 99.4 78.3 21.6 14.3 9.6 2027.5003 JUL 118.4 97.9 76.9 22.3 14.1 8.8 2027.5837 AUG 117.6 96.7 74.8 23.0 14.0 9.0 2027.6670 SEP 117.7 95.6 73.8 23.5 14.0 9.1 2027.7503 OCT 118.2 94.6 73.2 23.7 14.1 9.0 2027.8337 NOV 118.6 93.7 72.9 23.6 14.0 9.1 2027.9170 DEC 117.8 92.6 72.7 23.1 13.9 9.3 2028.0003 JAN 116.4 91.4 72.3 22.2 13.7 9.5 2028.0837 FEB 114.8 90.2 71.9 21.2 13.6 9.6 2028.1670 MAR 112.7 89.2 71.2 20.7 13.8 9.5 2028.2503 APR 109.1 88.1 70.6 20.3 13.8 9.4 2028.3337 MAY 104.8 86.8 70.3 20.0 14.0 9.5 2028.4170 JUN 102.1 85.8 69.9 19.6 14.0 9.8 2028.5003 JUL 100.6 84.9 69.7 18.9 13.9 9.8 2028.5837 AUG 99.1 84.1 69.7 18.1 13.7 9.6 2028.6670 SEP 97.1 83.1 69.5 18.2 13.5 9.4 2028.7503 OCT 95.5 82.0 69.1 18.3 13.3 9.1 2028.8337 NOV 93.6 80.9 68.9 18.1 13.1 8.5 2028.9170 DEC 92.5 80.1 68.7 17.7 12.9 8.0 2029.0003 JAN 92.2 79.4 68.7 17.2 12.9 7.5 2029.0837 FEB 91.3 78.8 68.5 16.5 12.8 7.0 2029.1670 MAR 90.3 78.0 68.3 15.5 12.7 6.3 2029.2503 APR 89.5 77.3 68.0 15.6 12.5 5.9 2029.3337 MAY 88.7 76.7 67.8 15.7 12.4 6.0 2029.4170 JUN 87.6 76.0 67.6 15.8 12.4 6.2 2029.5003 JUL 86.7 75.4 67.6 15.7 12.3 6.6 2029.5837 AUG 85.9 74.9 67.7 15.9 12.3 6.9 2029.6670 SEP 84.5 74.4 67.7 16.2 12.1 6.9 2029.7503 OCT 83.1 73.9 67.7 16.1 11.9 6.9 2029.8337 NOV 81.1 73.3 67.6 15.8 11.7 6.8 2029.9170 DEC 78.8 72.6 67.6 15.5 11.4 6.8 2030.0003 JAN 77.3 71.9 67.3 14.5 10.9 6.7 2030.0837 FEB 76.4 71.3 67.0 13.0 10.5 6.7 2030.1670 MAR 76.0 70.8 66.8 12.0 10.1 6.6 2030.2503 APR 75.8 70.4 66.8 12.1 9.7 6.5 2030.3337 MAY 75.6 70.0 66.7 11.8 9.4 6.5 2030.4170 JUN 75.5 69.7 66.5 11.4 9.0 6.2 2030.5003 JUL 75.1 69.4 66.3 11.1 8.7 5.7 2030.5837 AUG 74.1 69.1 66.3 10.8 8.5 5.4 2030.6670 SEP 73.2 68.7 66.3 10.1 8.3 5.7 2030.7503 OCT 73.0 68.5 66.3 9.6 8.1 5.5