Statistics of sunspot activity
September, 1991
Visual indices of solar activity by National Geophysical Data Center
| Date | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | Average | % |
| W | 226.00 | 163.14 | 181.50 | 247.80 | 184.17 | 178.67 | 144.60 | 181.33 | 159.80 | 165.33 | 158.00 | 158.17 | 188.33 | 192.50 | 180.20 | 132.67 | 134.50 | 179.67 | 124.33 | 138.50 | 147.00 | 155.20 | 179.40 | 142.67 | 144.88 | 153.29 | 158.86 | 195.33 | 203.67 | 153.00 | 168.42 | 100 |
| Wn | 75.57 | 56.43 | 50.88 | 60.20 | 36.83 | 29.00 | 3.00 | 44.83 | 56.60 | 47.33 | 40.80 | 36.67 | 61.67 | 83.33 | 77.00 | 58.67 | 70.17 | 119.33 | 94.33 | 91.83 | 86.60 | 84.60 | 89.40 | 66.50 | 71.38 | 58.57 | 41.43 | 50.33 | 47.67 | 31.00 | 60.73 | 36.06 |
| Ws | 150.43 | 106.71 | 130.63 | 187.60 | 147.33 | 149.67 | 141.60 | 136.50 | 103.20 | 118.00 | 117.20 | 121.50 | 126.67 | 109.17 | 103.20 | 74.00 | 64.33 | 60.33 | 30.00 | 46.67 | 60.40 | 70.60 | 90.00 | 76.17 | 73.50 | 94.71 | 117.43 | 145.00 | 156.00 | 122.00 | 107.68 | 63.94 |
| n | 9.14 | 9.00 | 8.38 | 11.20 | 9.00 | 9.83 | 7.80 | 8.67 | 8.00 | 8.33 | 8.40 | 8.50 | 9.83 | 10.33 | 10.20 | 7.67 | 7.67 | 11.00 | 6.50 | 8.67 | 9.20 | 8.20 | 8.80 | 8.83 | 8.13 | 7.86 | 8.00 | 9.33 | 7.50 | 6.20 | 8.67 | 100 |
| A | 1.00 | 1.14 | 0.13 | 0.60 | 0.33 | 1.00 | 0.40 | 1.17 | 1.00 | 1.00 | 1.20 | 0.67 | 0.83 | 0.50 | 1.20 | 1.83 | 1.50 | 3.67 | 1.00 | 3.50 | 1.80 | 0.60 | 0.20 | 1.00 | 2.50 | 1.86 | 1.00 | 2.33 | 1.17 | 1.20 | 1.24 | 14.35 |
| B | 0.43 | 0.43 | 0.63 | 1.40 | 0.83 | 1.17 | 0.60 | 0.67 | 0.60 | 1.00 | 0.00 | 0.67 | 0.83 | 0.83 | 1.00 | 0.17 | 1.67 | 4.00 | 2.33 | 1.67 | 2.00 | 3.20 | 2.80 | 2.00 | 1.13 | 0.71 | 2.71 | 3.00 | 2.00 | 0.80 | 1.38 | 15.86 |
| C | 0.71 | 1.43 | 1.75 | 3.40 | 2.83 | 2.33 | 0.40 | 0.67 | 0.60 | 0.33 | 0.40 | 0.33 | 0.83 | 2.00 | 1.40 | 1.33 | 2.67 | 1.00 | 1.00 | 0.50 | 2.20 | 1.80 | 2.80 | 3.17 | 1.75 | 1.86 | 1.00 | 1.00 | 0.33 | 0.20 | 1.40 | 16.16 |
| D | 2.71 | 3.14 | 3.88 | 3.80 | 2.67 | 2.00 | 2.00 | 3.67 | 3.20 | 3.33 | 2.80 | 3.00 | 3.83 | 4.00 | 2.40 | 2.00 | 1.17 | 0.33 | 0.00 | 0.17 | 0.20 | 0.40 | 1.20 | 1.50 | 1.88 | 2.14 | 1.29 | 0.83 | 1.83 | 1.40 | 2.09 | 24.13 |
| E | 1.00 | 0.57 | 0.00 | 0.80 | 0.67 | 0.83 | 1.00 | 0.83 | 0.20 | 0.33 | 0.00 | 0.00 | 0.17 | 0.33 | 0.20 | 0.00 | 0.17 | 0.67 | 1.00 | 0.67 | 0.60 | 0.40 | 0.00 | 0.00 | 0.50 | 0.14 | 0.29 | 0.50 | 0.67 | 1.00 | 0.45 | 5.20 |
| F | 0.43 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.40 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.71 | 0.86 | 1.17 | 0.83 | 0.80 | 0.18 | 2.13 |
| G | 0.71 | 0.71 | 0.75 | 0.00 | 0.00 | 0.00 | 0.20 | 0.17 | 0.40 | 0.00 | 1.20 | 1.00 | 0.67 | 0.17 | 0.40 | 0.33 | 0.00 | 0.00 | 0.00 | 0.17 | 0.40 | 0.20 | 0.20 | 0.00 | 0.13 | 0.43 | 0.57 | 0.33 | 0.67 | 0.80 | 0.35 | 4.08 |
| H | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.13 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.02 | 0.24 |
| I | 2.14 | 1.57 | 1.25 | 1.20 | 1.67 | 2.50 | 3.20 | 1.33 | 1.60 | 2.00 | 2.80 | 2.83 | 2.67 | 2.50 | 3.60 | 2.00 | 0.50 | 1.33 | 1.17 | 1.83 | 2.00 | 1.60 | 1.60 | 1.00 | 0.13 | 0.00 | 0.29 | 0.17 | 0.00 | 0.00 | 1.55 | 17.86 |
| x | 1.43 | 1.57 | 0.75 | 2.00 | 1.17 | 2.17 | 1.00 | 1.83 | 1.60 | 2.00 | 1.20 | 1.33 | 1.67 | 1.33 | 2.20 | 2.00 | 3.17 | 7.67 | 3.33 | 5.17 | 3.80 | 3.80 | 3.00 | 3.00 | 3.63 | 2.57 | 3.71 | 5.33 | 3.17 | 2.00 | 2.62 | 30.21 |
| r | 0.00 | 0.00 | 0.13 | 0.20 | 0.67 | 0.33 | 0.60 | 0.00 | 0.40 | 0.33 | 0.00 | 0.00 | 0.33 | 0.17 | 0.40 | 0.00 | 0.17 | 0.00 | 0.00 | 0.17 | 0.60 | 0.20 | 0.20 | 0.00 | 0.00 | 0.00 | 0.14 | 0.50 | 0.17 | 0.20 | 0.20 | 2.27 |
| s | 3.00 | 2.86 | 3.75 | 2.80 | 2.33 | 3.50 | 3.20 | 2.67 | 1.80 | 1.67 | 3.00 | 4.00 | 3.83 | 4.00 | 5.20 | 3.83 | 3.00 | 2.33 | 1.83 | 1.67 | 3.20 | 2.80 | 4.40 | 3.67 | 0.88 | 0.43 | 1.29 | 1.33 | 1.17 | 1.00 | 2.68 | 30.91 |
| a | 3.57 | 3.43 | 2.50 | 4.40 | 3.33 | 2.67 | 1.20 | 2.67 | 2.40 | 3.67 | 4.00 | 2.83 | 3.83 | 4.83 | 2.40 | 1.67 | 1.33 | 0.67 | 1.17 | 1.33 | 1.40 | 1.00 | 1.00 | 1.83 | 2.75 | 3.86 | 1.86 | 1.17 | 2.00 | 1.60 | 2.41 | 27.81 |
| h | 0.43 | 0.57 | 0.50 | 0.20 | 0.00 | 0.00 | 0.00 | 0.50 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.40 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.10 | 1.15 |
| k | 0.71 | 0.57 | 0.75 | 1.60 | 1.50 | 1.17 | 1.80 | 1.00 | 1.60 | 0.67 | 0.20 | 0.33 | 0.17 | 0.00 | 0.00 | 0.17 | 0.00 | 0.33 | 0.17 | 0.33 | 0.20 | 0.00 | 0.00 | 0.33 | 0.88 | 1.00 | 1.00 | 1.00 | 1.00 | 1.40 | 0.66 | 7.64 |
| x | 3.14 | 2.71 | 1.38 | 1.80 | 2.00 | 3.50 | 3.60 | 2.50 | 2.60 | 3.33 | 4.00 | 3.50 | 3.50 | 3.00 | 4.80 | 3.83 | 2.00 | 5.00 | 2.17 | 5.33 | 3.80 | 2.20 | 1.80 | 2.17 | 2.75 | 1.86 | 1.29 | 2.50 | 1.17 | 1.20 | 2.81 | 32.45 |
| o | 3.14 | 4.86 | 5.50 | 7.40 | 5.17 | 4.17 | 2.40 | 3.17 | 3.20 | 4.33 | 3.80 | 4.50 | 5.67 | 6.17 | 4.60 | 2.83 | 5.33 | 5.33 | 3.33 | 2.50 | 4.80 | 5.20 | 6.40 | 6.17 | 4.88 | 5.00 | 5.29 | 4.67 | 4.00 | 2.00 | 4.53 | 52.20 |
| i | 2.86 | 1.43 | 1.38 | 1.40 | 1.67 | 2.17 | 1.80 | 3.00 | 2.20 | 0.67 | 0.60 | 0.50 | 0.67 | 1.17 | 0.80 | 1.00 | 0.33 | 0.67 | 1.00 | 0.83 | 0.60 | 0.80 | 0.60 | 0.50 | 0.00 | 0.29 | 1.14 | 1.50 | 1.83 | 2.40 | 1.19 | 13.76 |
| c | 0.00 | 0.00 | 0.13 | 0.60 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.71 | 0.29 | 0.67 | 0.50 | 0.60 | 0.14 | 1.60 |
| CV | 168.14 | 156.57 | 167.25 | 191.60 | 149.00 | 138.83 | 147.40 | 168.83 | 155.80 | 116.00 | 119.80 | 127.67 | 137.33 | 139.17 | 118.20 | 92.17 | 65.67 | 65.67 | 54.33 | 62.00 | 75.60 | 74.20 | 88.40 | 90.00 | 100.88 | 121.29 | 112.14 | 115.67 | 128.50 | 137.20 | 119.51 | 100 |
| CVn | 65.00 | 62.43 | 56.13 | 56.40 | 43.50 | 29.67 | 5.00 | 20.83 | 29.40 | 22.33 | 24.80 | 31.00 | 48.50 | 64.83 | 48.20 | 38.17 | 33.50 | 47.67 | 40.83 | 43.83 | 50.20 | 50.00 | 44.60 | 30.83 | 26.00 | 24.29 | 13.14 | 13.17 | 25.00 | 25.40 | 37.15 | 31.09 |
| CVs | 103.14 | 94.14 | 111.13 | 135.20 | 105.50 | 109.17 | 142.40 | 148.00 | 126.40 | 93.67 | 95.00 | 96.67 | 88.83 | 74.33 | 70.00 | 54.00 | 32.17 | 18.00 | 13.50 | 18.17 | 25.40 | 24.20 | 43.80 | 59.17 | 74.88 | 97.00 | 99.00 | 102.50 | 103.50 | 111.80 | 82.36 | 68.91 |
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