| Monthly Observation SummaryJanuary 1999 | |||||||||||||
| Station "APLMD" (JHU/Applied Physics Laboratory), Laurel, MD (39°10'02"N, 76°53'52"W, 438 ft) | |||||||||||||
| Day | Max. Temp. | Min. Temp. | Rain Day | Rain Month | Rain Year | Max. Rn Rate | Peak Gust | Max. Light | Last Light | Min. Press. | Max. Press. | Min. RH | Max. RH |
| (°F) | (°F) | (in.) | (in.) | (in.) | (in./hr) | (mph) | (in.) | (in.) | (%) | (%) | |||
| 1 | 28 | 17 | 0.00 | 0.00 | 0.00 | 0.00 | 28 | 67 | 17:11 | 30.13 | 30.57 | 44 | 99 |
| 2 | 24 | 16 | 0.00 | 0.00 | 0.00 | 0.00 | 17 | 60 | 17:09 | 30.04 | 30.65 | 48 | 100 |
| 3 | 51 | 24 | 1.43 | 1.43 | 1.43 | 1.80 | 41 | 64 | 17:16 | 29.62 | 30.04 | 58 | 100 |
| 4 | 29 | 18 | 0.00 | 1.43 | 1.43 | 0.00 | 23 | 64 | 17:17 | 29.95 | 30.29 | 42 | 65 |
| 5 | 25 | 11 | 0.00 | 1.43 | 1.43 | 0.00 | 21 | 62 | 17:18 | 30.29 | 30.42 | 42 | 82 |
| 6 | 33 | 8 | 0.00 | 1.43 | 1.43 | 0.00 | 23 | 64 | 17:17 | 30.04 | 30.38 | 50 | 94 |
| 7 | 34 | 24 | 0.00 | 1.43 | 1.43 | 0.00 | 26 | 62 | 17:17 | 30.04 | 30.46 | 24 | 74 |
| 8 | 30 | 20 | 0.59 | 2.02 | 2.02 | 0.00 | 13 | 49 | 17:15 | 30.02 | 30.49 | 44 | 100 |
| 9 | 45 | 25 | 0.13 | 2.15 | 2.15 | 0.00 | 34 | 60 | 17:09 | 29.69 | 30.13 | 56 | 100 |
| 10 | 32 | 17 | 0.00 | 2.15 | 2.15 | 0.00 | 19 | 62 | 17:22 | 30.04 | 30.26 | 38 | 76 |
| 11 | 33 | 18 | 0.00 | 2.15 | 2.15 | 0.00 | 30 | 63 | 17:21 | 30.04 | 30.31 | 33 | 77 |
| 12 | 57 | 26 | 0.00 | 2.15 | 2.15 | 0.00 | 22 | 65 | 17:20 | 29.96 | 30.09 | 36 | 80 |
| 13 | 58 | 33 | 0.00 | 2.15 | 2.15 | 0.00 | 20 | 69 | 17:20 | 30.04 | 30.31 | 49 | 95 |
| 14 | 33 | 26 | 0.10 | 2.25 | 2.25 | 0.04 | 20 | 39 | 17:08 | 30.09 | 30.40 | 89 | 100 |
| 15 | 34 | 23 | 0.41 | 2.66 | 2.66 | 0.04 | msg. | 65 | 17:27 | 29.82 | 30.09 | 86 | 100 |
| 16 | 50 | 23 | 0.00 | 2.66 | 2.66 | 0.00 | 19 | 70 | 17:26 | 29.96 | 30.09 | 44 | 99 |
| 17 | 58 | 36 | 0.00 | 2.66 | 2.66 | 0.00 | 16 | 65 | 17:27 | 30.09 | 30.31 | 24 | 84 |
| 18 | 59 | 36 | 0.68 | 3.34 | 3.34 | 1.20 | 44 | 56 | 17:30 | 29.63 | 30.12 | 77 | 100 |
| 19 | 53 | 36 | 0.00 | 3.34 | 3.34 | 0.00 | 23 | 64 | 17:29 | 29.88 | 30.10 | 23 | 90 |
| 20 | 50 | 35 | 0.02 | 3.36 | 3.36 | 0.04 | 29 | 65 | 17:31 | 30.05 | 30.15 | 31 | 98 |
| 21 | 44 | 32 | 0.07 | 3.43 | 3.43 | 0.12 | 9 | 63 | 17:25 | 30.01 | 30.13 | 86 | 100 |
| 22 | 47 | 41 | 0.02 | 3.45 | 3.45 | 0.04 | 14 | 53 | 17:24 | 30.09 | 30.27 | 100 | 100 |
| 23 | 68 | 46 | 0.14 | 3.59 | 3.59 | 0.40 | 22 | 68 | 17:33 | 29.95 | 30.24 | 83 | 100 |
| 24 | 61 | 37 | 1.07 | 4.66 | 4.66 | 0.72 | 32 | 64 | 17:36 | 29.85 | 30.12 | 67 | 100 |
| 25 | 47 | 33 | 0.00 | 4.66 | 4.66 | 0.00 | 21 | 70 | 17:37 | 30.09 | 30.40 | 55 | 85 |
| 26 | 50 | 32 | 0.00 | 4.66 | 4.66 | 0.00 | 18 | 67 | 17:37 | 30.31 | 30.49 | 44 | 90 |
| 27 | 55 | 27 | 0.00 | 4.66 | 4.66 | 0.00 | 15 | 66 | 17:38 | 29.88 | 30.32 | 50 | 100 |
| 28 | 68 | 40 | 0.00 | 4.66 | 4.66 | 0.00 | 31 | 71 | 17:34 | 29.90 | 30.07 | 44 | 93 |
| 29 | 50 | 31 | 0.00 | 4.66 | 4.66 | 0.00 | 28 | 70 | 17:40 | 30.07 | 30.43 | 42 | 81 |
| 30 | 45 | 25 | 0.00 | 4.66 | 4.66 | 0.00 | 18 | 68 | 17:41 | 30.40 | 30.62 | 42 | 94 |
| 31 | 34 | 21 | 0.00 | 4.66 | 4.66 | 0.00 | 16 | 69 | 17:42 | 30.62 | 30.79 | 35 | 76 |
| Avg. | 44.7 | 27.0 | |||||||||||
| Max. | 68 | 1.43 | 1.80 | 44 | 71 | 30.79 | 100 | 100 | |||||
| Min. | 8 | 9 | 39 | 29.62 | 23 | 65 | |||||||