TABLE 5 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 75.0% 50% 5.0% 95.0% 50% 5.0% 2016.9170 DEC 81.3 80.5 78.5 11.8 10.9 10.1 2017.0003 JAN 80.8 79.6 76.1 12.7 11.1 9.7 2017.0837 FEB 79.9 78.8 74.4 13.3 11.3 9.5 2017.1670 MAR 80.7 78.3 73.1 13.8 11.6 9.3 2017.2503 APR 79.8 78.0 72.7 15.1 11.8 9.2 2017.3337 MAY 79.4 77.5 72.6 16.5 12.2 9.5 2017.4170 JUN 78.9 77.1 71.8 16.9 12.5 9.8 2017.5003 JUL 78.9 76.7 70.1 16.5 12.6 9.9 2017.5837 AUG 78.8 76.3 69.6 16.8 12.6 9.5 2017.6670 SEP 78.3 76.0 69.0 17.5 12.8 9.6 2017.7503 OCT 77.9 75.5 68.3 18.0 12.9 9.5 2017.8337 NOV 78.4 75.1 67.1 18.1 13.0 9.1 2017.9170 DEC 78.3 75.0 65.3 17.9 13.0 8.7 2018.0003 JAN 78.3 74.9 64.0 17.6 13.0 8.3 2018.0837 FEB 77.8 74.7 63.5 17.0 13.1 7.9 2018.1670 MAR 77.1 74.4 63.4 16.8 13.2 7.3 2018.2503 APR 76.6 74.0 63.4 17.2 13.2 7.1 2018.3337 MAY 75.6 73.6 63.5 17.3 13.2 7.2 2018.4170 JUN 75.2 73.3 63.7 17.4 13.2 7.5 2018.5003 JUL 74.9 73.0 64.0 17.4 13.2 8.0 2018.5837 AUG 74.6 72.7 64.3 17.6 13.3 8.4 2018.6670 SEP 74.3 72.4 64.6 17.8 13.2 8.4 2018.7503 OCT 74.0 72.2 64.8 17.7 12.9 8.3 2018.8337 NOV 73.7 71.9 65.1 17.3 12.5 8.1 2018.9170 DEC 73.4 71.6 65.3 16.6 12.1 8.0 2019.0003 JAN 73.1 71.4 65.6 15.9 11.7 7.9 2019.0837 FEB 72.8 71.1 65.8 15.2 11.3 7.7 2019.1670 MAR 72.6 70.9 66.0 14.5 10.9 7.6 2019.2503 APR 72.4 70.7 66.2 13.9 10.6 7.5 2019.3337 MAY 72.1 70.5 66.4 13.3 10.2 7.4 2019.4170 JUN 72.0 70.4 66.5 12.7 9.9 7.3 2019.5003 JUL 71.8 70.2 66.7 12.3 9.6 7.2 2019.5837 AUG 71.7 70.1 66.8 11.8 9.4 7.1 2019.6670 SEP 71.5 70.0 66.9 11.5 9.2 7.0 2019.7503 OCT 71.5 69.9 66.9 11.3 9.1 7.0 2019.8337 NOV 71.4 69.9 67.0 11.1 9.0 7.0 2019.9170 DEC 71.4 69.9 67.0 11.1 9.0 6.9 2020.0003 JAN 71.9 70.0 67.0 11.3 9.0 6.9 2020.0837 FEB 72.1 70.3 67.1 11.6 9.2 7.1 2020.1670 MAR 72.8 70.7 67.2 11.7 9.3 7.4 2020.2503 APR 72.5 71.0 67.2 11.9 9.4 7.5 2020.3337 MAY 72.9 71.5 67.4 12.0 9.5 7.5 2020.4170 JUN 73.3 72.0 67.5 12.1 9.6 7.3 2020.5003 JUL 73.8 72.6 67.6 12.2 9.7 7.2 2020.5837 AUG 75.1 73.3 67.8 12.5 9.9 7.1 2020.6670 SEP 76.7 74.1 67.9 12.8 10.1 7.0 2020.7503 OCT 78.1 75.1 68.0 13.2 10.5 7.2 2020.8337 NOV 79.9 76.3 68.3 13.7 10.8 7.6 2020.9170 DEC 82.0 77.7 68.4 14.5 11.1 7.9 2021.0003 JAN 85.2 79.2 68.4 15.7 11.4 7.7 2021.0837 FEB 88.2 80.9 68.4 16.1 11.6 7.7 2021.1670 MAR 90.2 82.9 68.4 16.3 11.8 7.6 2021.2503 APR 92.2 85.1 68.3 16.8 12.0 7.6 2021.3337 MAY 95.6 87.3 68.6 18.0 12.3 7.6 2021.4170 JUN 99.1 89.9 68.7 18.9 12.6 7.7 2021.5003 JUL 103.5 92.6 68.9 19.1 12.7 7.7 2021.5837 AUG 108.5 95.4 69.2 19.2 12.9 7.8 2021.6670 SEP 112.0 98.2 69.2 19.0 13.1 7.7 2021.7503 OCT 116.5 101.0 69.5 18.6 13.1 7.7 2021.8337 NOV 120.8 103.9 69.9 18.5 13.2 7.8 2021.9170 DEC 124.1 107.0 70.6 18.9 13.4 8.0 2022.0003 JAN 126.7 110.1 70.9 18.8 13.5 8.2 2022.0837 FEB 129.2 113.2 71.3 17.8 13.5 8.6 2022.1670 MAR 133.3 116.5 71.5 17.9 13.7 8.7 2022.2503 APR 138.2 119.7 72.1 18.5 13.9 8.7 2022.3337 MAY 142.8 122.9 72.9 19.1 14.2 9.0 2022.4170 JUN 148.3 125.7 73.3 19.6 14.6 9.4 2022.5003 JUL 152.9 128.2 74.1 20.3 14.9 9.6 2022.5837 AUG 157.7 130.5 74.7 20.3 15.1 9.6 2022.6670 SEP 163.7 132.6 75.1 20.3 15.1 9.8 2022.7503 OCT 169.4 135.1 75.6 20.5 15.2 10.0 2022.8337 NOV 174.6 137.7 75.9 20.8 15.4 10.5 2022.9170 DEC 180.2 140.3 76.1 21.2 15.4 11.1 2023.0003 JAN 183.5 142.4 76.1 21.3 15.3 11.6 2023.0837 FEB 185.6 144.3 76.0 21.4 15.1 11.3 2023.1670 MAR 185.7 146.0 76.1 21.6 15.0 11.2 2023.2503 APR 185.2 147.7 76.6 22.0 15.0 10.7 2023.3337 MAY 184.2 149.0 76.9 22.8 14.9 10.2 2023.4170 JUN 184.6 149.9 77.6 22.5 14.7 9.9 2023.5003 JUL 187.3 150.8 78.9 21.3 14.5 10.1 2023.5837 AUG 190.1 151.2 79.7 20.6 14.3 10.1 2023.6670 SEP 191.7 151.4 80.6 20.1 14.2 10.3 2023.7503 OCT 191.8 151.7 82.2 19.6 14.1 10.6 2023.8337 NOV 191.4 151.9 83.8 19.5 14.0 10.6 2023.9170 DEC 189.8 152.0 85.6 19.3 14.0 10.5 2024.0003 JAN 186.5 151.2 86.4 19.1 14.2 10.5 2024.0837 FEB 182.2 149.7 87.8 18.9 14.6 10.5 2024.1670 MAR 177.4 148.7 89.5 18.9 14.7 10.3 2024.2503 APR 173.9 148.4 90.7 19.5 14.6 9.8 2024.3337 MAY 177.0 148.5 93.0 20.4 14.7 10.2 2024.4170 JUN 176.6 148.9 94.2 22.0 15.0 10.7 2024.5003 JUL 173.8 149.0 95.5 23.4 15.3 10.7 2024.5837 AUG 172.7 148.7 95.8 24.0 15.4 10.9 2024.6670 SEP 171.7 148.1 95.4 25.1 15.7 11.1 2024.7503 OCT 170.6 147.5 95.4 25.6 15.9 11.3 2024.8337 NOV 167.1 147.3 96.9 24.9 15.9 11.5 2024.9170 DEC 163.8 147.2 97.7 24.8 15.9 11.7 2025.0003 JAN 161.2 146.4 97.2 23.9 15.8 11.9 2025.0837 FEB 158.7 145.1 96.4 22.1 15.8 11.8 2025.1670 MAR 155.9 143.5 96.3 22.4 15.9 12.0 2025.2503 APR 155.7 141.8 96.8 23.1 16.0 11.8 2025.3337 MAY 156.4 140.1 96.3 23.1 16.0 11.1 2025.4170 JUN 154.9 138.8 95.5 22.6 16.0 10.8 2025.5003 JUL 151.2 137.4 96.1 22.0 15.8 10.8 2025.5837 AUG 147.1 135.6 97.1 21.9 15.8 10.8 2025.6670 SEP 144.2 133.7 96.2 22.7 16.1 10.8 2025.7503 OCT 144.9 132.2 94.5 23.7 16.5 10.8 2025.8337 NOV 142.3 130.9 93.8 23.9 16.7 10.8 2025.9170 DEC 137.0 129.5 93.6 23.9 17.0 10.7 2026.0003 JAN 134.3 127.8 91.7 23.9 17.1 10.6 2026.0837 FEB 134.9 125.9 88.3 23.5 17.2 10.3 2026.1670 MAR 134.0 124.6 87.9 22.5 17.2 10.5 2026.2503 APR 134.3 123.5 88.7 22.7 17.2 10.7 2026.3337 MAY 132.9 122.3 87.3 23.0 17.4 11.4 2026.4170 JUN 131.5 121.0 86.3 23.1 17.6 11.9 2026.5003 JUL 130.4 119.3 85.7 22.5 17.8 12.0 2026.5837 AUG 129.7 117.4 84.8 21.7 17.6 12.1 2026.6670 SEP 126.8 115.6 83.6 21.2 17.4 12.3 2026.7503 OCT 125.7 113.7 82.5 21.7 17.0 12.5 2026.8337 NOV 125.9 111.7 82.1 21.7 16.9 13.3 2026.9170 DEC 124.1 110.0 82.1 22.1 16.9 13.1 2027.0003 JAN 122.4 108.6 82.0 22.6 17.0 12.8 2027.0837 FEB 120.8 107.0 80.9 22.3 16.8 13.1 2027.1670 MAR 118.9 105.5 80.5 22.4 16.5 12.7 2027.2503 APR 116.4 104.0 80.6 22.7 16.2 12.5 2027.3337 MAY 115.2 102.5 80.0 22.9 15.8 12.1 2027.4170 JUN 114.2 100.9 79.1 23.5 15.6 11.2 2027.5003 JUL 111.9 99.4 77.7 24.1 15.4 10.5 2027.5837 AUG 108.1 98.2 75.6 24.8 15.3 10.7 2027.6670 SEP 106.6 97.1 74.5 25.3 15.3 10.8 2027.7503 OCT 105.0 96.1 74.0 25.6 15.3 10.6 2027.8337 NOV 104.3 95.2 73.6 25.4 15.3 10.8 2027.9170 DEC 102.5 94.2 73.4 24.9 15.2 11.0 2028.0003 JAN 100.8 92.9 73.0 24.0 15.0 11.1 2028.0837 FEB 99.1 91.7 72.7 23.0 14.9 11.3 2028.1670 MAR 98.3 90.7 71.9 22.5 15.0 11.2 2028.2503 APR 98.3 89.6 71.4 22.1 15.1 11.1 2028.3337 MAY 97.9 88.4 71.0 21.8 15.2 11.2 2028.4170 JUN 97.0 87.3 70.7 21.4 15.3 11.4 2028.5003 JUL 95.7 86.5 70.4 20.7 15.2 11.5 2028.5837 AUG 95.0 85.6 70.5 19.9 14.9 11.3 2028.6670 SEP 93.3 84.7 70.3 20.0 14.7 11.1 2028.7503 OCT 91.0 83.5 69.8 20.1 14.6 10.8 2028.8337 NOV 89.6 82.4 69.6 19.9 14.3 10.1 2028.9170 DEC 88.2 81.7 69.5 19.5 14.2 9.6 2029.0003 JAN 86.7 81.0 69.4 19.0 14.1 9.1 2029.0837 FEB 86.0 80.3 69.3 18.3 14.1 8.6 2029.1670 MAR 85.4 79.6 69.1 17.3 14.0 8.0 2029.2503 APR 84.3 78.9 68.8 17.4 13.8 7.5 2029.3337 MAY 82.9 78.2 68.5 17.5 13.7 7.6 2029.4170 JUN 81.8 77.5 68.3 17.6 13.7 7.8 2029.5003 JUL 81.3 77.0 68.4 17.5 13.6 8.3 2029.5837 AUG 81.0 76.5 68.4 17.7 13.5 8.6 2029.6670 SEP 80.8 75.9 68.5 18.1 13.4 8.5 2029.7503 OCT 79.4 75.4 68.4 17.9 13.2 8.6 2029.8337 NOV 78.0 74.9 68.4 17.6 12.9 8.5 2029.9170 DEC 77.4 74.2 68.3 17.3 12.6 8.5 2030.0003 JAN 76.8 73.5 68.0 16.3 12.2 8.4 2030.0837 FEB 75.8 72.8 67.8 14.8 11.8 8.4 2030.1670 MAR 75.6 72.3 67.6 13.8 11.4 8.3 2030.2503 APR 74.6 72.0 67.6 13.9 11.0 8.2 2030.3337 MAY 73.4 71.6 67.5 13.6 10.6 8.2 2030.4170 JUN 73.5 71.2 67.2 13.2 10.3 7.9 2030.5003 JUL 72.6 70.9 67.1 12.9 9.9 7.4 2030.5837 AUG 72.3 70.6 67.1 12.6 9.7 7.1 2030.6670 SEP 72.2 70.3 67.0 11.9 9.5 7.3 2030.7503 OCT 71.9 70.1 67.0 11.4 9.4 7.1