Noise Levels at Different Periods
The table below gives the decibel 10% noise level (in db) for each month in
several period bands. The 10% noise level is defined as the signal
level not exceeded 10% of the time, based on hourly measurements. Each entry in the
table is color coded with reference to the New Low Noise Model (NLNM, Peterson, 1993):
navy, -6 db < value-NLNM < -3 db
blue, -3 db < value-NLNM < 3 db
aqua, 3 db < value-NLNM < 6 db
lime, 6 db < value-NLNM < 9 db
yellow, 9 db < value-NLNM < 12 db
orange, 12 db < value-NLNM < 15 db
red, 15 db < value-NLNM < 20 db
fuchsia, 20 db < value-NLNM < 25 db
silver, value-NLNM < -6 db, value-NLNM > 25 db
Black indicates that there was an insufficient number of hourly measurements to calculate a noise level.
| Month | Chan. | Qual. | # obs. | 518s | 439s | 373s | 316s | 268s | 228s | 193s | 164s | 139s | 118s | 100s | 85s | 72s | 61s | 52s | 44s | 37s | 32s | 27s | 23s | 19s | 16s | 14s | 12s | 10s |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 202504 | LH2-00 | AR | 510 | -107 | -108 | -108 | -110 | -111 | -112 | -113 | -114 | -114 | -116 | -118 | -120 | -120 | -120 | -123 | -127 | -128 | -129 | -127 | -123 | -118 | -113 | -114 | -116 | -116 |
| 202502 | LH2-00 | AR | 578 | -128 | -129 | -128 | -127 | -128 | -126 | -124 | -124 | -121 | -122 | -123 | -124 | -122 | -121 | -124 | -127 | -128 | -128 | -128 | -126 | -121 | -115 | -114 | -116 | -118 |
| 202501 | LH2-00 | AR | 731 | -128 | -127 | -127 | -128 | -127 | -125 | -123 | -123 | -120 | -120 | -122 | -123 | -122 | -120 | -124 | -127 | -127 | -128 | -127 | -124 | -119 | -115 | -115 | -119 | -122 |
| 202412 | LH2-00 | AR | 738 | -127 | -126 | -127 | -126 | -126 | -125 | -123 | -123 | -121 | -121 | -121 | -122 | -121 | -120 | -123 | -127 | -127 | -129 | -128 | -126 | -122 | -118 | -116 | -117 | -118 |
| 202411 | LH2-00 | AR | 714 | -126 | -127 | -126 | -126 | -126 | -124 | -122 | -122 | -121 | -121 | -120 | -121 | -120 | -119 | -123 | -126 | -127 | -128 | -127 | -125 | -120 | -117 | -115 | -117 | -117 |
| 202410 | LH2-00 | AR | 738 | -126 | -126 | -126 | -126 | -125 | -124 | -122 | -123 | -121 | -121 | -120 | -120 | -119 | -119 | -123 | -126 | -127 | -128 | -127 | -124 | -119 | -115 | -113 | -112 | -113 |
| 202409 | LH2-00 | AR | 710 | -123 | -124 | -124 | -124 | -123 | -123 | -121 | -120 | -119 | -119 | -119 | -120 | -119 | -119 | -122 | -125 | -126 | -127 | -126 | -124 | -120 | -115 | -113 | -115 | -117 |
| 202408 | LH2-00 | AR | 718 | -122 | -122 | -120 | -120 | -120 | -119 | -119 | -117 | -117 | -116 | -117 | -118 | -117 | -118 | -121 | -124 | -125 | -127 | -127 | -125 | -121 | -116 | -112 | -110 | -111 |
| 202407 | LH2-00 | AR | 735 | -123 | -123 | -123 | -122 | -121 | -121 | -119 | -118 | -117 | -118 | -118 | -118 | -118 | -118 | -122 | -125 | -126 | -127 | -127 | -124 | -118 | -114 | -112 | -111 | -113 |
| 202406 | LH2-00 | AR | 714 | -125 | -125 | -124 | -124 | -123 | -122 | -121 | -120 | -120 | -119 | -119 | -120 | -119 | -119 | -123 | -126 | -127 | -128 | -127 | -124 | -118 | -113 | -110 | -111 | -116 |
| 202405 | LH2-00 | AR | 742 | -124 | -123 | -124 | -123 | -122 | -121 | -120 | -119 | -117 | -118 | -117 | -118 | -118 | -118 | -122 | -125 | -126 | -127 | -126 | -122 | -116 | -112 | -111 | -112 | -114 |
| 202404 | LH2-00 | AR | 716 | -125 | -125 | -125 | -125 | -125 | -123 | -122 | -120 | -119 | -118 | -119 | -120 | -120 | -119 | -122 | -126 | -126 | -127 | -126 | -123 | -118 | -115 | -113 | -116 | -116 |
| 202403 | LH2-00 | AR | 744 | -127 | -127 | -127 | -127 | -126 | -124 | -122 | -122 | -120 | -120 | -121 | -122 | -120 | -119 | -123 | -126 | -127 | -128 | -127 | -123 | -118 | -115 | -115 | -117 | -120 |
| 202402 | LH2-00 | AR | 692 | -126 | -126 | -126 | -126 | -126 | -124 | -122 | -122 | -120 | -120 | -121 | -122 | -120 | -119 | -123 | -126 | -127 | -127 | -126 | -123 | -118 | -114 | -113 | -114 | -117 |
| 202401 | LH2-00 | AR | 700 | -127 | -127 | -127 | -127 | -126 | -125 | -123 | -123 | -121 | -121 | -121 | -122 | -120 | -119 | -122 | -126 | -127 | -127 | -126 | -124 | -119 | -116 | -114 | -117 | -121 |
| 202312 | LH2-00 | AR | 736 | -127 | -127 | -126 | -126 | -126 | -124 | -122 | -122 | -120 | -120 | -120 | -121 | -119 | -119 | -123 | -126 | -127 | -128 | -127 | -124 | -120 | -117 | -116 | -115 | -114 |
| 202311 | LH2-00 | AR | 685 | -125 | -125 | -125 | -125 | -124 | -122 | -120 | -120 | -119 | -119 | -119 | -119 | -118 | -117 | -122 | -125 | -126 | -127 | -127 | -125 | -121 | -116 | -112 | -113 | -113 |
| 202310 | LH2-00 | AR | 622 | -124 | -124 | -123 | -124 | -123 | -121 | -121 | -120 | -119 | -119 | -119 | -118 | -117 | -117 | -121 | -124 | -126 | -126 | -125 | -122 | -118 | -113 | -111 | -113 | -112 |
| 202309 | LH2-00 | AR | 720 | -124 | -123 | -123 | -123 | -122 | -121 | -120 | -119 | -118 | -118 | -117 | -118 | -117 | -117 | -121 | -124 | -125 | -127 | -126 | -124 | -120 | -115 | -111 | -108 | -111 |
| 202308 | LH2-00 | AR | 402 | -124 | -124 | -124 | -124 | -124 | -123 | -121 | -120 | -119 | -120 | -119 | -119 | -118 | -118 | -121 | -125 | -125 | -127 | -126 | -122 | -115 | -111 | -111 | -110 | -112 |
| 202307 | LH2-00 | AR | 697 | -124 | -124 | -124 | -123 | -123 | -122 | -120 | -119 | -118 | -118 | -118 | -119 | -118 | -119 | -122 | -125 | -126 | -127 | -127 | -124 | -119 | -115 | -113 | -113 | -114 |
| 202306 | LH2-00 | AR | 696 | -125 | -125 | -124 | -124 | -124 | -123 | -122 | -121 | -121 | -120 | -120 | -120 | -119 | -119 | -123 | -126 | -127 | -128 | -127 | -125 | -120 | -115 | -111 | -110 | -113 |
| 202305 | LH2-00 | AR | 731 | -122 | -122 | -122 | -122 | -121 | -119 | -118 | -117 | -116 | -115 | -116 | -117 | -115 | -115 | -119 | -122 | -123 | -125 | -124 | -121 | -116 | -111 | -109 | -111 | -113 |
| 202304 | LH2-00 | AR | 629 | -127 | -127 | -128 | -128 | -128 | -126 | -125 | -124 | -122 | -121 | -122 | -123 | -121 | -121 | -124 | -127 | -128 | -128 | -128 | -125 | -120 | -115 | -111 | -112 | -116 |
| 202303 | LH2-00 | AR | 714 | -127 | -127 | -127 | -127 | -126 | -125 | -124 | -123 | -120 | -120 | -121 | -123 | -122 | -120 | -124 | -127 | -127 | -128 | -128 | -126 | -121 | -117 | -114 | -114 | -116 |
| 202302 | LH2-00 | AR | 451 | -128 | -128 | -128 | -127 | -126 | -125 | -123 | -122 | -120 | -120 | -121 | -122 | -121 | -119 | -123 | -126 | -127 | -127 | -126 | -124 | -118 | -115 | -114 | -117 | -120 |
| 202301 | LH2-00 | AR | 738 | -127 | -127 | -126 | -127 | -126 | -123 | -122 | -122 | -120 | -120 | -121 | -122 | -120 | -118 | -122 | -126 | -126 | -127 | -126 | -123 | -118 | -115 | -113 | -115 | -117 |
| 202212 | LH2-00 | AR | 736 | -126 | -126 | -125 | -125 | -125 | -123 | -122 | -122 | -120 | -120 | -121 | -122 | -120 | -120 | -124 | -127 | -128 | -128 | -128 | -126 | -120 | -115 | -114 | -117 | -120 |
| 202211 | LH2-00 | AR | 716 | -127 | -127 | -127 | -127 | -127 | -125 | -123 | -122 | -120 | -121 | -121 | -123 | -122 | -120 | -123 | -127 | -128 | -128 | -128 | -125 | -120 | -115 | -113 | -115 | -119 |
| 202210 | LH2-00 | AR | 741 | -125 | -125 | -124 | -125 | -124 | -122 | -121 | -121 | -120 | -119 | -119 | -120 | -119 | -119 | -122 | -126 | -127 | -128 | -127 | -124 | -117 | -111 | -110 | -113 | -116 |
| 202209 | LH2-00 | AR | 715 | -123 | -123 | -122 | -122 | -122 | -120 | -120 | -119 | -119 | -118 | -118 | -118 | -118 | -118 | -122 | -125 | -126 | -128 | -127 | -123 | -117 | -113 | -112 | -112 | -113 |
| 202208 | LH2-00 | AR | 1 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |
| 202205 | LH2-00 | AR | 213 | -140 | -140 | -139 | -137 | -134 | -130 | -128 | -124 | -121 | -119 | -118 | -117 | -116 | -114 | -118 | -122 | -123 | -124 | -123 | -120 | -113 | -109 | -108 | -110 | -114 |
| 202204 | LH2-00 | AR | 357 | -142 | -142 | -140 | -139 | -136 | -132 | -128 | -125 | -122 | -121 | -120 | -121 | -118 | -116 | -119 | -123 | -123 | -123 | -123 | -120 | -115 | -111 | -110 | -112 | -115 |
| 202203 | LH2-00 | AR | 741 | -143 | -143 | -141 | -140 | -137 | -134 | -129 | -127 | -123 | -122 | -120 | -121 | -118 | -117 | -120 | -123 | -124 | -125 | -124 | -121 | -116 | -112 | -110 | -111 | -113 |
| 202202 | LH2-00 | AR | 672 | -143 | -142 | -140 | -139 | -136 | -133 | -129 | -126 | -122 | -120 | -120 | -121 | -119 | -117 | -121 | -124 | -124 | -125 | -125 | -122 | -116 | -113 | -112 | -114 | -117 |
| 202201 | LH2-00 | AR | 742 | -144 | -143 | -141 | -140 | -138 | -134 | -129 | -127 | -123 | -122 | -122 | -122 | -120 | -118 | -122 | -125 | -125 | -126 | -126 | -124 | -121 | -115 | -113 | -116 | -119 |
| 202112 | LH2-00 | AR | 743 | -137 | -137 | -135 | -134 | -132 | -129 | -126 | -124 | -123 | -123 | -124 | -125 | -124 | -123 | -127 | -130 | -131 | -132 | -131 | -129 | -124 | -119 | -117 | -118 | -117 |
| 202111 | LH2-00 | AR | 720 | -127 | -127 | -127 | -127 | -126 | -125 | -124 | -124 | -124 | -124 | -124 | -125 | -124 | -124 | -128 | -130 | -131 | -132 | -131 | -129 | -126 | -120 | -117 | -116 | -116 |
| 202110 | LH2-00 | AR | 744 | -125 | -126 | -126 | -125 | -124 | -123 | -122 | -122 | -122 | -122 | -122 | -123 | -122 | -122 | -126 | -129 | -130 | -131 | -130 | -127 | -122 | -118 | -117 | -115 | -114 |
| 202109 | LH2-00 | AR | 718 | -122 | -122 | -122 | -122 | -121 | -121 | -120 | -119 | -118 | -119 | -120 | -120 | -121 | -121 | -125 | -128 | -129 | -130 | -128 | -125 | -119 | -114 | -112 | -113 | -114 |
| 202108 | LH2-00 | AR | 193 | -121 | -121 | -121 | -120 | -122 | -120 | -121 | -118 | -116 | -117 | -118 | -119 | -118 | -119 | -123 | -126 | -127 | -128 | -128 | -125 | -120 | -116 | -114 | -113 | -110 |
| 202105 | LH2-00 | AR | 289 | -125 | -124 | -123 | -123 | -123 | -122 | -121 | -120 | -119 | -119 | -119 | -121 | -120 | -119 | -123 | -127 | -127 | -128 | -128 | -124 | -117 | -112 | -113 | -113 | -114 |
| 202104 | LH2-00 | AR | 720 | -125 | -125 | -125 | -125 | -125 | -123 | -122 | -121 | -120 | -121 | -121 | -122 | -121 | -120 | -124 | -128 | -128 | -129 | -128 | -124 | -120 | -116 | -116 | -118 | -121 |
| 202103 | LH2-00 | AR | 744 | -126 | -127 | -126 | -126 | -126 | -125 | -124 | -123 | -122 | -122 | -123 | -124 | -123 | -122 | -126 | -129 | -129 | -130 | -129 | -127 | -122 | -117 | -115 | -115 | -118 |
| 202102 | LH2-00 | AR | 653 | -127 | -128 | -127 | -127 | -127 | -126 | -124 | -124 | -122 | -123 | -124 | -125 | -124 | -123 | -127 | -130 | -130 | -130 | -129 | -127 | -120 | -116 | -117 | -119 | -122 |
| 202101 | LH2-00 | AR | 744 | -127 | -126 | -127 | -127 | -126 | -124 | -122 | -122 | -121 | -121 | -122 | -124 | -122 | -121 | -125 | -129 | -129 | -130 | -128 | -124 | -120 | -118 | -118 | -122 | -123 |
| 202012 | LH2-00 | AR | 744 | -126 | -126 | -126 | -127 | -126 | -124 | -123 | -123 | -122 | -122 | -122 | -124 | -123 | -122 | -126 | -130 | -130 | -131 | -130 | -128 | -124 | -120 | -119 | -121 | -120 |
| 202011 | LH2-00 | AR | 720 | -128 | -127 | -127 | -128 | -128 | -127 | -125 | -125 | -123 | -123 | -124 | -125 | -123 | -122 | -126 | -129 | -130 | -131 | -130 | -128 | -124 | -120 | -119 | -120 | -122 |
| 202010 | LH2-00 | AR | 744 | -124 | -124 | -124 | -124 | -124 | -123 | -121 | -120 | -119 | -119 | -120 | -121 | -120 | -120 | -124 | -127 | -128 | -129 | -129 | -127 | -122 | -117 | -115 | -116 | -115 |
| 202009 | LH2-00 | AR | 720 | -124 | -123 | -124 | -123 | -123 | -121 | -120 | -119 | -118 | -118 | -119 | -120 | -119 | -119 | -123 | -126 | -128 | -129 | -128 | -125 | -120 | -117 | -116 | -116 | -115 |
| 202008 | LH2-00 | AR | 744 | -123 | -123 | -123 | -123 | -123 | -121 | -120 | -120 | -119 | -120 | -120 | -121 | -120 | -121 | -125 | -128 | -129 | -130 | -129 | -127 | -122 | -117 | -114 | -114 | -115 |
| 202007 | LH2-00 | AR | 744 | -125 | -124 | -125 | -124 | -124 | -123 | -122 | -121 | -120 | -121 | -120 | -121 | -120 | -121 | -125 | -128 | -129 | -130 | -129 | -126 | -122 | -117 | -114 | -113 | -116 |
| 202006 | LH2-00 | AR | 719 | -123 | -124 | -124 | -124 | -124 | -123 | -121 | -121 | -119 | -120 | -120 | -120 | -119 | -119 | -122 | -126 | -127 | -128 | -127 | -123 | -117 | -113 | -111 | -112 | -114 |
| 202005 | LH2-00 | AR | 736 | -124 | -124 | -123 | -123 | -123 | -122 | -121 | -119 | -118 | -118 | -119 | -120 | -120 | -120 | -124 | -127 | -127 | -129 | -128 | -124 | -118 | -113 | -111 | -113 | -116 |
| 202004 | LH2-00 | AR | 714 | -127 | -127 | -127 | -128 | -127 | -125 | -124 | -123 | -121 | -121 | -122 | -124 | -123 | -121 | -125 | -129 | -129 | -130 | -129 | -125 | -120 | -116 | -114 | -116 | -120 |
| 202003 | LH2-00 | AR | 743 | -125 | -124 | -125 | -125 | -125 | -123 | -122 | -121 | -118 | -119 | -120 | -122 | -122 | -121 | -125 | -128 | -129 | -130 | -129 | -127 | -121 | -117 | -116 | -117 | -118 |
| 202002 | LH2-00 | AR | 693 | -127 | -127 | -127 | -127 | -127 | -125 | -124 | -124 | -122 | -123 | -123 | -124 | -122 | -122 | -126 | -129 | -130 | -131 | -130 | -128 | -124 | -119 | -117 | -118 | -119 |
| 202001 | LH2-00 | AR | 737 | -126 | -126 | -126 | -125 | -125 | -124 | -122 | -122 | -121 | -121 | -122 | -123 | -122 | -122 | -126 | -129 | -129 | -130 | -129 | -126 | -121 | -117 | -117 | -118 | -120 |
| 201912 | LH2-00 | AR | 744 | -126 | -126 | -126 | -126 | -125 | -123 | -122 | -122 | -120 | -120 | -121 | -123 | -122 | -122 | -125 | -129 | -130 | -131 | -130 | -128 | -123 | -120 | -119 | -119 | -120 |
| 201911 | LH2-00 | AR | 720 | -128 | -128 | -127 | -127 | -128 | -126 | -124 | -125 | -123 | -123 | -123 | -124 | -123 | -122 | -126 | -129 | -131 | -131 | -130 | -127 | -122 | -117 | -117 | -118 | -121 |
| 201910 | LH2-00 | AR | 737 | -126 | -126 | -126 | -126 | -125 | -125 | -123 | -123 | -122 | -122 | -122 | -123 | -122 | -121 | -125 | -129 | -130 | -131 | -130 | -126 | -121 | -116 | -115 | -116 | -120 |
| 201909 | LH2-00 | AR | 720 | -124 | -124 | -123 | -123 | -123 | -122 | -121 | -120 | -119 | -119 | -120 | -120 | -120 | -120 | -124 | -127 | -128 | -129 | -128 | -124 | -119 | -114 | -112 | -114 | -117 |
| 201908 | LH2-00 | AR | 744 | -123 | -122 | -123 | -123 | -123 | -122 | -121 | -120 | -119 | -119 | -119 | -120 | -120 | -120 | -124 | -127 | -128 | -129 | -128 | -125 | -120 | -115 | -113 | -115 | -116 |
| 201907 | LH2-00 | AR | 743 | -122 | -122 | -121 | -121 | -121 | -120 | -119 | -118 | -116 | -117 | -117 | -118 | -118 | -118 | -122 | -125 | -126 | -127 | -127 | -123 | -117 | -113 | -111 | -112 | -114 |
| 201906 | LH2-00 | AR | 696 | -119 | -119 | -119 | -119 | -119 | -118 | -117 | -117 | -117 | -118 | -120 | -121 | -121 | -122 | -126 | -129 | -130 | -132 | -131 | -128 | -122 | -118 | -117 | -118 | -118 |
| 201905 | LH2-00 | AR | 654 | -109 | -109 | -110 | -111 | -112 | -113 | -113 | -115 | -115 | -117 | -119 | -120 | -120 | -120 | -124 | -128 | -128 | -130 | -129 | -125 | -118 | -115 | -114 | -115 | -117 |
| 201903 | LH2-00 | AR | 539 | -126 | -127 | -127 | -126 | -126 | -125 | -123 | -123 | -122 | -122 | -121 | -121 | -120 | -120 | -124 | -128 | -129 | -129 | -128 | -124 | -118 | -115 | -115 | -115 | -115 |
| 201902 | LH2-00 | AR | 103 | -124 | -124 | -121 | -120 | -120 | -119 | -118 | -117 | -114 | -115 | -117 | -119 | -119 | -119 | -124 | -127 | -127 | -128 | -127 | -126 | -121 | -116 | -112 | -112 | -117 |
| 201812 | LH2-00 | AR | 495 | -126 | -126 | -127 | -127 | -127 | -125 | -123 | -123 | -122 | -121 | -122 | -123 | -121 | -120 | -123 | -127 | -128 | -128 | -127 | -124 | -120 | -116 | -115 | -116 | -118 |
| 201811 | LH2-00 | AR | 719 | -126 | -126 | -126 | -127 | -126 | -125 | -123 | -123 | -121 | -122 | -122 | -122 | -121 | -120 | -123 | -127 | -128 | -128 | -128 | -126 | -122 | -116 | -114 | -115 | -117 |
| 201810 | LH2-00 | AR | 719 | -125 | -124 | -124 | -124 | -123 | -122 | -121 | -121 | -119 | -118 | -119 | -120 | -119 | -118 | -121 | -125 | -126 | -126 | -126 | -123 | -117 | -112 | -110 | -112 | -116 |
| 201809 | LH2-00 | AR | 697 | -122 | -122 | -122 | -121 | -121 | -120 | -118 | -118 | -117 | -117 | -117 | -117 | -117 | -117 | -121 | -124 | -125 | -126 | -125 | -121 | -116 | -111 | -113 | -111 | -111 |
| 201808 | LH2-00 | AR | 743 | -125 | -125 | -125 | -125 | -125 | -123 | -123 | -122 | -120 | -120 | -121 | -121 | -120 | -120 | -123 | -126 | -127 | -128 | -127 | -124 | -118 | -114 | -113 | -115 | -117 |
| 201807 | LH2-00 | AR | 288 | -125 | -126 | -125 | -126 | -126 | -124 | -122 | -122 | -119 | -119 | -120 | -120 | -120 | -119 | -123 | -126 | -127 | -127 | -126 | -122 | -116 | -114 | -114 | -113 | -113 |
| 201806 | LH2-00 | AR | 512 | -125 | -125 | -125 | -125 | -125 | -124 | -122 | -121 | -119 | -119 | -120 | -120 | -120 | -119 | -122 | -126 | -126 | -127 | -126 | -122 | -117 | -113 | -113 | -112 | -115 |
| 201805 | LH2-00 | AR | 744 | -123 | -123 | -123 | -123 | -122 | -121 | -120 | -118 | -116 | -116 | -117 | -119 | -118 | -118 | -121 | -125 | -125 | -126 | -126 | -123 | -119 | -113 | -111 | -114 | -117 |
| 201804 | LH2-00 | AR | 720 | -126 | -126 | -126 | -127 | -127 | -125 | -123 | -123 | -120 | -120 | -121 | -123 | -121 | -119 | -122 | -126 | -126 | -127 | -126 | -124 | -119 | -114 | -113 | -115 | -118 |
| 201803 | LH2-00 | AR | 744 | -126 | -126 | -126 | -127 | -126 | -125 | -123 | -122 | -120 | -120 | -120 | -122 | -121 | -119 | -122 | -126 | -126 | -127 | -127 | -126 | -122 | -116 | -114 | -114 | -116 |
| 201802 | LH2-00 | AR | 64 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 | 999 |