Statistics of sunspot activity
April, 1988
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 | 116.60 | 100.60 | 95.67 | 80.83 | 60.83 | 71.50 | 94.17 | 106.20 | 114.83 | 106.00 | 132.86 | 150.57 | 132.57 | 146.17 | 167.20 | 149.71 | 129.00 | 142.33 | 115.80 | 96.50 | 99.80 | 78.50 | 57.67 | 43.86 | 49.00 | 46.83 | 52.17 | 45.40 | 45.83 | 60.00 | 96.30 | 100 |
| Wn | 64.20 | 54.80 | 53.00 | 45.17 | 35.50 | 42.33 | 57.17 | 71.20 | 70.00 | 64.86 | 80.00 | 94.71 | 75.86 | 71.17 | 90.20 | 80.71 | 68.67 | 94.83 | 87.80 | 69.50 | 64.40 | 48.33 | 32.33 | 18.57 | 6.71 | 0.00 | 4.83 | 0.00 | 0.00 | 2.75 | 51.65 | 53.64 |
| Ws | 52.40 | 45.80 | 42.67 | 35.67 | 25.33 | 29.17 | 37.00 | 35.00 | 44.83 | 41.14 | 52.86 | 55.86 | 56.71 | 75.00 | 77.00 | 69.00 | 60.33 | 47.50 | 28.00 | 27.00 | 35.40 | 30.17 | 25.33 | 25.29 | 42.29 | 46.83 | 47.33 | 45.40 | 45.83 | 57.25 | 44.65 | 46.36 |
| n | 4.40 | 4.40 | 4.33 | 4.33 | 4.00 | 4.33 | 5.83 | 6.20 | 6.83 | 5.86 | 7.71 | 9.14 | 8.00 | 7.67 | 8.00 | 7.86 | 7.00 | 7.00 | 5.00 | 4.00 | 5.00 | 4.50 | 4.17 | 3.71 | 3.14 | 2.83 | 3.00 | 2.60 | 3.00 | 3.75 | 5.25 | 100 |
| A | 0.40 | 0.40 | 0.33 | 0.00 | 0.17 | 0.17 | 0.67 | 0.60 | 0.83 | 0.00 | 0.71 | 1.00 | 1.14 | 1.00 | 1.20 | 1.86 | 2.00 | 1.17 | 0.60 | 0.00 | 0.40 | 1.17 | 1.00 | 0.71 | 0.29 | 0.67 | 0.67 | 0.20 | 0.17 | 1.00 | 0.68 | 13.02 |
| B | 0.40 | 0.20 | 0.00 | 0.33 | 0.50 | 1.50 | 0.33 | 0.60 | 0.33 | 0.00 | 0.71 | 1.29 | 0.14 | 1.17 | 0.80 | 0.00 | 0.17 | 0.83 | 0.00 | 0.50 | 1.20 | 0.83 | 1.00 | 0.43 | 0.43 | 0.17 | 0.33 | 0.40 | 0.67 | 0.50 | 0.53 | 10.00 |
| C | 1.40 | 1.00 | 1.33 | 1.50 | 0.83 | 0.67 | 0.67 | 1.60 | 1.50 | 1.14 | 2.57 | 1.71 | 0.57 | 2.00 | 1.80 | 1.57 | 0.83 | 1.17 | 0.40 | 0.67 | 0.80 | 0.83 | 0.00 | 0.00 | 0.29 | 0.17 | 0.17 | 0.40 | 0.83 | 1.25 | 0.99 | 18.83 |
| D | 0.80 | 1.20 | 0.67 | 0.83 | 0.33 | 0.17 | 1.83 | 1.60 | 0.83 | 1.14 | 0.86 | 1.86 | 1.00 | 1.17 | 2.40 | 2.43 | 1.67 | 1.17 | 1.00 | 0.83 | 1.00 | 0.17 | 0.17 | 0.57 | 0.71 | 0.83 | 0.83 | 0.80 | 0.33 | 0.00 | 0.97 | 18.53 |
| E | 1.00 | 0.60 | 0.33 | 0.17 | 0.00 | 0.33 | 0.00 | 0.00 | 0.17 | 0.00 | 0.14 | 0.57 | 1.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.17 | 0.00 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.16 | 3.04 |
| F | 0.00 | 0.20 | 0.67 | 0.17 | 0.17 | 0.00 | 0.00 | 0.00 | 0.67 | 0.57 | 0.43 | 0.14 | 0.57 | 0.67 | 0.80 | 0.71 | 0.67 | 0.83 | 1.00 | 0.83 | 0.60 | 0.33 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.34 | 6.47 |
| G | 0.00 | 0.00 | 0.67 | 1.17 | 1.17 | 0.67 | 1.00 | 1.60 | 1.83 | 1.29 | 0.57 | 0.43 | 0.43 | 0.50 | 0.20 | 0.43 | 0.33 | 0.33 | 0.40 | 0.17 | 0.60 | 0.50 | 0.83 | 0.14 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.51 | 9.68 |
| H | 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 | 0.17 | 0.17 | 0.20 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 | 0.29 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.04 | 0.73 |
| I | 0.40 | 0.80 | 0.33 | 0.17 | 0.83 | 0.83 | 1.33 | 0.20 | 0.67 | 1.71 | 1.71 | 2.14 | 3.14 | 1.17 | 0.80 | 0.86 | 1.17 | 1.33 | 1.40 | 1.00 | 0.40 | 0.50 | 0.67 | 1.86 | 1.00 | 1.00 | 0.83 | 0.80 | 1.00 | 1.00 | 1.04 | 19.71 |
| x | 0.80 | 0.60 | 0.33 | 0.33 | 0.67 | 1.67 | 1.00 | 1.20 | 1.17 | 0.00 | 1.43 | 2.29 | 1.29 | 2.17 | 2.00 | 1.86 | 2.17 | 2.00 | 0.60 | 0.50 | 1.60 | 2.00 | 2.00 | 1.14 | 0.71 | 0.83 | 1.00 | 0.60 | 0.83 | 1.50 | 1.21 | 23.02 |
| r | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.50 | 1.00 | 0.60 | 0.17 | 0.14 | 0.14 | 0.86 | 0.57 | 0.33 | 0.20 | 0.00 | 0.00 | 0.33 | 0.40 | 0.17 | 1.40 | 0.33 | 0.17 | 0.29 | 0.29 | 0.00 | 0.00 | 0.00 | 0.17 | 0.25 | 0.29 | 5.48 |
| s | 1.60 | 2.20 | 2.33 | 1.50 | 1.33 | 1.17 | 1.83 | 1.80 | 3.00 | 3.14 | 4.14 | 3.71 | 3.71 | 3.17 | 2.40 | 2.86 | 2.17 | 2.17 | 1.80 | 1.17 | 0.80 | 1.17 | 1.00 | 2.29 | 1.57 | 1.33 | 1.50 | 1.20 | 1.17 | 1.75 | 2.03 | 38.69 |
| a | 1.20 | 1.20 | 1.33 | 2.00 | 1.50 | 0.83 | 1.67 | 2.20 | 2.33 | 2.29 | 1.43 | 1.86 | 1.86 | 1.83 | 2.60 | 2.00 | 1.67 | 1.33 | 1.00 | 1.17 | 0.40 | 0.33 | 0.33 | 0.00 | 0.29 | 0.50 | 0.33 | 0.40 | 0.83 | 0.25 | 1.23 | 23.45 |
| h | 0.60 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.17 | 0.40 | 0.17 | 0.00 | 0.00 | 0.14 | 0.14 | 0.17 | 0.20 | 0.29 | 0.00 | 0.17 | 0.40 | 0.33 | 0.60 | 0.33 | 0.33 | 0.00 | 0.00 | 0.17 | 0.00 | 0.40 | 0.00 | 0.00 | 0.17 | 3.30 |
| k | 0.20 | 0.20 | 0.33 | 0.50 | 0.17 | 0.17 | 0.17 | 0.00 | 0.00 | 0.29 | 0.57 | 0.29 | 0.43 | 0.00 | 0.60 | 0.86 | 1.00 | 1.00 | 0.80 | 0.67 | 0.20 | 0.33 | 0.33 | 0.00 | 0.29 | 0.00 | 0.17 | 0.00 | 0.00 | 0.00 | 0.32 | 6.06 |
| x | 0.80 | 1.20 | 0.67 | 0.17 | 1.00 | 1.00 | 2.00 | 0.80 | 1.50 | 1.71 | 2.43 | 3.14 | 4.29 | 2.17 | 2.00 | 2.71 | 3.33 | 2.67 | 2.20 | 1.00 | 0.80 | 1.67 | 2.00 | 2.57 | 1.57 | 1.67 | 1.50 | 1.00 | 1.17 | 2.00 | 1.76 | 33.45 |
| o | 2.40 | 2.00 | 2.33 | 3.67 | 2.83 | 2.83 | 3.50 | 4.40 | 4.33 | 3.00 | 3.57 | 4.00 | 1.57 | 3.67 | 5.00 | 3.57 | 2.33 | 2.50 | 0.60 | 1.33 | 2.80 | 1.83 | 2.00 | 1.14 | 0.86 | 0.17 | 0.83 | 1.20 | 1.67 | 1.25 | 2.44 | 46.44 |
| i | 1.00 | 1.20 | 1.33 | 0.50 | 0.17 | 0.50 | 0.33 | 1.00 | 1.00 | 1.14 | 1.71 | 2.00 | 2.14 | 1.83 | 1.00 | 1.57 | 1.33 | 1.83 | 2.20 | 1.67 | 1.40 | 1.00 | 0.17 | 0.00 | 0.71 | 1.00 | 0.67 | 0.40 | 0.17 | 0.50 | 1.05 | 19.98 |
| c | 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 | 0.00 | 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 | 0.01 | 0.13 |
| CV | 85.40 | 76.80 | 81.00 | 81.17 | 56.00 | 45.67 | 83.33 | 101.60 | 111.33 | 102.43 | 104.86 | 118.14 | 119.57 | 95.33 | 121.20 | 136.43 | 110.00 | 110.67 | 107.60 | 84.33 | 79.80 | 59.50 | 56.83 | 34.71 | 43.14 | 37.33 | 39.83 | 41.80 | 25.17 | 24.00 | 79.17 | 100 |
| CVn | 30.80 | 30.60 | 52.33 | 51.83 | 29.83 | 29.33 | 49.50 | 62.20 | 65.00 | 62.43 | 72.57 | 92.57 | 80.14 | 45.00 | 58.80 | 87.29 | 72.83 | 85.17 | 87.00 | 69.83 | 67.80 | 48.67 | 35.67 | 13.00 | 8.43 | 0.00 | 0.50 | 0.00 | 0.00 | 0.25 | 46.31 | 58.50 |
| CVs | 54.60 | 46.20 | 28.67 | 29.33 | 26.17 | 16.33 | 33.83 | 39.40 | 46.33 | 40.00 | 32.29 | 25.57 | 39.43 | 50.33 | 62.40 | 49.14 | 37.17 | 25.50 | 20.60 | 14.50 | 12.00 | 10.83 | 21.17 | 21.71 | 34.71 | 37.33 | 39.33 | 41.80 | 25.17 | 23.75 | 32.85 | 41.50 |
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