Statistics of sunspot activity
April, 1990
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 | 133.83 | 145.50 | 142.33 | 168.83 | 175.75 | 214.75 | 167.43 | 115.67 | 120.20 | 98.25 | 112.50 | 124.33 | 137.67 | 155.83 | 214.50 | 234.00 | 296.00 | 296.25 | 265.50 | 311.75 | 261.00 | 258.20 | 234.14 | 201.40 | 211.40 | 190.60 | 183.20 | 116.00 | 126.40 | 115.00 | 184.27 | 100 |
| Wn | 56.67 | 75.17 | 69.33 | 96.50 | 100.25 | 127.75 | 97.71 | 75.00 | 78.00 | 73.25 | 71.50 | 71.67 | 80.50 | 84.00 | 103.75 | 108.40 | 129.00 | 121.25 | 113.00 | 132.00 | 109.67 | 118.20 | 110.00 | 99.00 | 108.80 | 92.00 | 90.20 | 64.83 | 62.40 | 53.00 | 92.43 | 50.16 |
| Ws | 77.17 | 70.33 | 73.00 | 72.33 | 75.50 | 87.00 | 69.71 | 40.67 | 42.20 | 25.00 | 41.00 | 52.67 | 57.17 | 71.83 | 110.75 | 125.60 | 167.00 | 175.00 | 152.50 | 179.75 | 151.33 | 140.00 | 124.14 | 102.40 | 102.60 | 98.60 | 93.00 | 51.17 | 64.00 | 62.00 | 91.85 | 49.84 |
| n | 8.17 | 8.83 | 9.17 | 9.50 | 9.75 | 13.00 | 10.43 | 7.33 | 8.40 | 7.50 | 8.00 | 8.67 | 7.50 | 7.17 | 10.00 | 10.40 | 11.50 | 11.00 | 9.75 | 12.00 | 12.50 | 12.20 | 11.86 | 11.80 | 12.40 | 12.40 | 11.00 | 7.00 | 8.60 | 8.67 | 9.88 | 100 |
| A | 0.33 | 0.33 | 1.17 | 0.33 | 0.25 | 1.50 | 1.57 | 1.17 | 1.20 | 1.25 | 2.75 | 1.33 | 0.67 | 0.67 | 0.75 | 3.00 | 1.75 | 1.50 | 0.50 | 2.75 | 1.00 | 1.80 | 0.86 | 0.80 | 1.40 | 1.00 | 1.00 | 0.00 | 0.80 | 1.17 | 1.15 | 11.67 |
| B | 0.83 | 1.50 | 1.17 | 1.50 | 2.00 | 1.25 | 3.14 | 1.17 | 1.80 | 1.25 | 1.25 | 2.33 | 0.50 | 0.50 | 2.00 | 2.60 | 2.25 | 3.25 | 3.00 | 1.50 | 1.50 | 1.20 | 2.00 | 1.20 | 1.80 | 2.20 | 1.40 | 1.50 | 2.20 | 1.50 | 1.71 | 17.30 |
| C | 1.00 | 1.50 | 1.50 | 1.50 | 1.50 | 2.75 | 1.43 | 0.83 | 1.00 | 2.00 | 1.25 | 2.00 | 0.67 | 1.83 | 1.75 | 0.60 | 2.50 | 0.50 | 1.50 | 1.75 | 2.33 | 3.40 | 3.29 | 4.60 | 4.00 | 4.00 | 1.40 | 1.33 | 2.00 | 2.83 | 1.95 | 19.75 |
| D | 3.00 | 2.17 | 1.83 | 2.33 | 1.75 | 2.25 | 1.29 | 1.33 | 1.20 | 0.75 | 1.00 | 1.00 | 3.00 | 1.67 | 2.00 | 0.80 | 0.75 | 2.25 | 0.75 | 2.00 | 3.00 | 2.80 | 3.86 | 4.00 | 4.20 | 3.20 | 4.20 | 2.33 | 2.60 | 0.83 | 2.14 | 21.63 |
| E | 0.33 | 0.50 | 0.67 | 0.83 | 1.00 | 1.25 | 0.29 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.75 | 1.00 | 0.75 | 0.25 | 0.75 | 0.25 | 0.50 | 0.40 | 0.43 | 0.20 | 0.20 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.37 | 3.73 |
| F | 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 | 0.33 | 0.75 | 0.60 | 1.00 | 1.50 | 0.50 | 1.00 | 0.67 | 0.60 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 2.56 |
| G | 0.33 | 0.50 | 0.33 | 0.17 | 0.00 | 0.00 | 0.71 | 1.00 | 1.20 | 0.50 | 0.25 | 0.00 | 1.17 | 1.00 | 0.50 | 0.40 | 1.00 | 1.25 | 2.00 | 2.00 | 2.00 | 1.80 | 0.29 | 0.20 | 0.00 | 0.00 | 0.40 | 0.67 | 0.20 | 0.67 | 0.68 | 6.93 |
| H | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.14 | 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 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.02 | 0.15 |
| I | 2.33 | 2.33 | 2.50 | 2.83 | 3.25 | 4.00 | 1.86 | 1.83 | 2.00 | 1.75 | 1.50 | 2.00 | 1.00 | 0.67 | 1.50 | 1.40 | 1.50 | 0.50 | 0.75 | 0.75 | 1.50 | 0.20 | 0.86 | 0.80 | 0.80 | 1.80 | 2.60 | 1.00 | 0.80 | 1.67 | 1.61 | 16.28 |
| x | 1.17 | 1.83 | 2.33 | 1.83 | 2.25 | 2.75 | 4.71 | 2.33 | 3.00 | 2.50 | 4.00 | 3.67 | 1.17 | 1.17 | 2.75 | 5.60 | 4.00 | 4.75 | 3.50 | 4.25 | 2.50 | 3.00 | 2.86 | 2.00 | 3.20 | 3.20 | 2.40 | 1.50 | 3.00 | 2.67 | 2.86 | 28.97 |
| r | 0.17 | 0.33 | 1.00 | 0.67 | 0.50 | 1.50 | 0.29 | 0.00 | 0.20 | 0.75 | 0.00 | 0.67 | 0.50 | 0.00 | 0.75 | 0.00 | 1.75 | 0.00 | 0.00 | 0.25 | 0.00 | 0.20 | 0.14 | 0.40 | 0.20 | 0.60 | 0.20 | 0.17 | 0.40 | 0.67 | 0.41 | 4.15 |
| s | 4.00 | 3.50 | 3.50 | 3.67 | 2.75 | 3.50 | 2.86 | 1.83 | 2.40 | 2.25 | 2.00 | 2.00 | 1.83 | 2.00 | 2.25 | 1.20 | 0.75 | 0.75 | 0.50 | 1.00 | 2.50 | 1.00 | 2.14 | 1.40 | 2.20 | 1.60 | 1.00 | 1.50 | 1.40 | 2.33 | 2.05 | 20.78 |
| a | 2.33 | 2.17 | 1.33 | 2.33 | 3.00 | 4.00 | 1.71 | 2.67 | 2.00 | 1.00 | 2.00 | 2.33 | 3.17 | 3.00 | 3.25 | 2.60 | 4.00 | 4.25 | 4.50 | 4.50 | 5.67 | 6.00 | 5.00 | 6.20 | 6.00 | 6.60 | 7.40 | 3.50 | 3.80 | 3.00 | 3.64 | 36.87 |
| h | 0.33 | 0.33 | 0.33 | 0.17 | 0.25 | 0.50 | 0.29 | 0.17 | 0.40 | 0.50 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.40 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 | 0.00 | 0.15 | 1.57 |
| k | 0.17 | 0.67 | 0.67 | 0.83 | 1.00 | 0.75 | 0.57 | 0.33 | 0.40 | 0.50 | 0.00 | 0.00 | 0.83 | 0.83 | 1.00 | 1.00 | 1.00 | 1.25 | 1.25 | 2.00 | 1.50 | 1.60 | 1.57 | 1.80 | 0.80 | 0.40 | 0.00 | 0.00 | 0.00 | 0.00 | 0.76 | 7.67 |
| x | 2.67 | 2.67 | 3.67 | 3.17 | 3.50 | 5.50 | 3.57 | 3.00 | 3.20 | 3.00 | 4.25 | 3.33 | 1.67 | 1.33 | 2.25 | 4.40 | 3.25 | 2.00 | 1.25 | 3.50 | 2.50 | 2.00 | 1.86 | 1.60 | 2.20 | 2.80 | 3.60 | 1.17 | 1.60 | 2.83 | 2.78 | 28.11 |
| o | 5.00 | 5.67 | 4.83 | 5.50 | 4.75 | 6.25 | 6.57 | 4.17 | 5.20 | 4.50 | 3.50 | 5.00 | 5.00 | 4.67 | 5.75 | 3.80 | 6.25 | 7.00 | 7.25 | 7.00 | 8.17 | 7.60 | 7.43 | 8.40 | 9.20 | 8.40 | 7.00 | 5.83 | 7.00 | 5.83 | 6.08 | 61.56 |
| i | 0.50 | 0.50 | 0.67 | 0.83 | 1.50 | 1.25 | 0.29 | 0.17 | 0.00 | 0.00 | 0.25 | 0.33 | 0.83 | 1.00 | 2.00 | 2.20 | 2.00 | 2.00 | 1.25 | 1.00 | 1.83 | 2.60 | 2.29 | 1.60 | 1.00 | 1.20 | 0.40 | 0.00 | 0.00 | 0.00 | 0.98 | 9.95 |
| c | 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 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.50 | 0.00 | 0.00 | 0.29 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.04 | 0.39 |
| CV | 128.17 | 133.33 | 124.83 | 139.00 | 135.75 | 167.50 | 111.57 | 89.00 | 103.00 | 90.00 | 56.50 | 61.00 | 133.00 | 128.83 | 143.75 | 112.20 | 134.50 | 160.50 | 140.75 | 193.50 | 220.00 | 204.80 | 193.86 | 186.00 | 154.60 | 131.20 | 125.80 | 95.50 | 82.00 | 73.67 | 131.80 | 100 |
| CVn | 63.00 | 69.83 | 65.17 | 88.83 | 101.00 | 119.25 | 86.71 | 63.33 | 74.80 | 69.00 | 44.00 | 41.33 | 90.83 | 85.83 | 84.25 | 70.60 | 81.00 | 83.00 | 69.50 | 77.50 | 111.50 | 99.00 | 104.57 | 95.80 | 96.00 | 72.60 | 66.20 | 50.17 | 43.20 | 32.50 | 76.68 | 58.18 |
| CVs | 65.17 | 63.50 | 59.67 | 50.17 | 34.75 | 48.25 | 24.86 | 25.67 | 28.20 | 21.00 | 12.50 | 19.67 | 42.17 | 43.00 | 59.50 | 41.60 | 53.50 | 77.50 | 71.25 | 116.00 | 108.50 | 105.80 | 89.29 | 90.20 | 58.60 | 58.60 | 59.60 | 45.33 | 38.80 | 41.17 | 55.13 | 41.82 |
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