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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 202405 | LH2-00 | AR | 302 | -146 | -150 | -152 | -153 | -156 | -156 | -154 | -153 | -152 | -152 | -151 | -151 | -151 | -151 | -151 | -151 | -152 | -152 | -154 | -155 | -155 | -155 | -152 | -150 | -149 |
| 202404 | LH2-00 | AR | 544 | -148 | -151 | -152 | -153 | -156 | -155 | -154 | -154 | -153 | -153 | -153 | -153 | -153 | -154 | -154 | -155 | -155 | -156 | -157 | -157 | -156 | -152 | -148 | -149 | -148 |
| 202403 | LH2-00 | AR | 736 | -147 | -150 | -151 | -153 | -154 | -152 | -151 | -150 | -149 | -148 | -148 | -147 | -147 | -147 | -147 | -147 | -147 | -148 | -149 | -149 | -149 | -148 | -148 | -146 | -144 |
| 202402 | LH2-00 | AR | 72 | 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 |
| 202401 | LH2-00 | AR | 540 | -124 | -128 | -130 | -132 | -135 | -137 | -138 | -139 | -141 | -141 | -141 | -141 | -142 | -142 | -142 | -142 | -143 | -145 | -145 | -146 | -147 | -149 | -149 | -149 | -146 |
| 202312 | LH2-00 | AR | 491 | -125 | -126 | -129 | -132 | -135 | -137 | -138 | -140 | -141 | -142 | -143 | -144 | -145 | -146 | -146 | -148 | -148 | -149 | -150 | -151 | -152 | -151 | -148 | -147 | -145 |
| 202311 | LH2-00 | AR | 539 | -125 | -129 | -131 | -133 | -136 | -137 | -138 | -139 | -141 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -143 | -145 | -145 | -146 | -146 | -147 | -146 |
| 202310 | LH2-00 | AR | 307 | -125 | -129 | -131 | -133 | -137 | -139 | -141 | -142 | -144 | -144 | -145 | -145 | -146 | -147 | -146 | -147 | -148 | -149 | -149 | -149 | -150 | -150 | -149 | -149 | -147 |
| 202309 | LH2-00 | AR | 719 | -125 | -128 | -131 | -135 | -138 | -139 | -140 | -142 | -144 | -144 | -145 | -146 | -146 | -146 | -147 | -148 | -149 | -150 | -152 | -153 | -153 | -150 | -146 | -145 | -145 |
| 202308 | LH2-00 | AR | 406 | -126 | -130 | -132 | -135 | -139 | -140 | -142 | -143 | -144 | -146 | -148 | -150 | -151 | -152 | -152 | -154 | -155 | -158 | -160 | -161 | -161 | -160 | -158 | -156 | -151 |
| 202307 | LH2-00 | AR | 736 | -125 | -126 | -128 | -130 | -133 | -135 | -137 | -138 | -139 | -139 | -139 | -139 | -139 | -139 | -139 | -138 | -138 | -139 | -139 | -139 | -140 | -141 | -142 | -143 | -144 |
| 202306 | LH2-00 | AR | 719 | -125 | -127 | -129 | -131 | -135 | -136 | -138 | -139 | -140 | -140 | -141 | -140 | -140 | -140 | -140 | -140 | -141 | -141 | -141 | -142 | -143 | -145 | -147 | -148 | -148 |
| 202305 | LH2-00 | AR | 741 | -124 | -127 | -130 | -133 | -136 | -138 | -139 | -141 | -141 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -143 | -143 | -144 | -145 | -146 | -147 | -147 | -149 | -148 |
| 202304 | LH2-00 | AR | 714 | -124 | -127 | -130 | -134 | -137 | -139 | -141 | -142 | -144 | -146 | -147 | -148 | -149 | -149 | -150 | -150 | -151 | -152 | -152 | -153 | -154 | -154 | -150 | -149 | -148 |
| 202303 | LH2-00 | AR | 737 | -125 | -128 | -131 | -133 | -137 | -139 | -140 | -142 | -143 | -145 | -146 | -147 | -148 | -149 | -149 | -150 | -151 | -152 | -153 | -153 | -152 | -147 | -143 | -146 | -146 |
| 202302 | LH2-00 | AR | 651 | -124 | -126 | -128 | -130 | -132 | -133 | -135 | -136 | -137 | -138 | -138 | -138 | -138 | -138 | -138 | -138 | -138 | -138 | -138 | -139 | -139 | -140 | -141 | -142 | -142 |
| 202301 | LH2-00 | AR | 717 | -124 | -127 | -129 | -131 | -134 | -136 | -136 | -137 | -139 | -140 | -141 | -141 | -141 | -141 | -142 | -142 | -142 | -142 | -143 | -144 | -145 | -145 | -145 | -145 | -144 |
| 202212 | LH2-00 | AR | 732 | -124 | -127 | -129 | -132 | -135 | -137 | -137 | -139 | -140 | -142 | -143 | -144 | -145 | -147 | -147 | -148 | -149 | -150 | -152 | -152 | -149 | -145 | -143 | -143 | -143 |
| 202211 | LH2-00 | AR | 668 | -123 | -125 | -128 | -131 | -134 | -135 | -136 | -137 | -138 | -139 | -139 | -139 | -139 | -139 | -139 | -139 | -139 | -139 | -139 | -140 | -141 | -142 | -143 | -144 | -144 |
| 202210 | LH2-00 | AR | 702 | -124 | -127 | -130 | -133 | -137 | -138 | -139 | -141 | -142 | -143 | -143 | -143 | -143 | -143 | -143 | -143 | -144 | -145 | -145 | -146 | -147 | -147 | -148 | -150 | -149 |
| 202209 | LH2-00 | AR | 694 | -125 | -128 | -131 | -134 | -137 | -138 | -140 | -141 | -142 | -143 | -143 | -143 | -143 | -143 | -144 | -144 | -145 | -146 | -146 | -147 | -148 | -150 | -151 | -150 | -148 |
| 202208 | LH2-00 | AR | 717 | -126 | -127 | -129 | -133 | -136 | -137 | -139 | -140 | -141 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -143 | -143 | -145 | -146 | -147 | -149 | -148 |
| 202207 | LH2-00 | AR | 740 | -124 | -126 | -127 | -130 | -132 | -133 | -135 | -136 | -137 | -137 | -137 | -137 | -137 | -137 | -136 | -136 | -136 | -136 | -136 | -136 | -136 | -137 | -138 | -139 | -140 |
| 202206 | LH2-00 | AR | 713 | -126 | -128 | -130 | -133 | -136 | -137 | -139 | -141 | -141 | -142 | -142 | -141 | -141 | -141 | -141 | -141 | -141 | -142 | -142 | -143 | -143 | -144 | -146 | -147 | -148 |
| 202205 | LH2-00 | AR | 256 | -126 | -127 | -131 | -133 | -136 | -137 | -138 | -139 | -140 | -140 | -140 | -140 | -140 | -140 | -139 | -139 | -139 | -139 | -139 | -139 | -140 | -141 | -142 | -143 | -145 |
| 202112 | LH2-00 | AR | 321 | -122 | -124 | -127 | -129 | -131 | -133 | -135 | -136 | -137 | -137 | -138 | -138 | -137 | -137 | -137 | -137 | -137 | -136 | -136 | -136 | -137 | -138 | -139 | -140 | -140 |
| 202111 | LH2-00 | AR | 699 | -125 | -128 | -131 | -134 | -137 | -138 | -139 | -141 | -142 | -143 | -144 | -144 | -145 | -145 | -145 | -146 | -147 | -147 | -148 | -149 | -150 | -151 | -149 | -148 | -148 |
| 202110 | LH2-00 | AR | 733 | -125 | -127 | -131 | -134 | -138 | -139 | -141 | -142 | -144 | -145 | -147 | -148 | -149 | -150 | -150 | -152 | -152 | -154 | -155 | -157 | -157 | -155 | -153 | -152 | -151 |
| 202109 | LH2-00 | AR | 720 | -125 | -129 | -132 | -135 | -138 | -140 | -141 | -143 | -144 | -145 | -147 | -148 | -149 | -150 | -150 | -151 | -151 | -153 | -154 | -155 | -156 | -153 | -150 | -150 | -150 |
| 202108 | LH2-00 | AR | 742 | -125 | -128 | -130 | -132 | -135 | -137 | -138 | -140 | -141 | -141 | -141 | -141 | -141 | -141 | -141 | -141 | -141 | -142 | -142 | -143 | -144 | -145 | -146 | -147 | -147 |
| 202107 | LH2-00 | AR | 742 | -126 | -127 | -129 | -131 | -133 | -135 | -136 | -137 | -138 | -138 | -138 | -138 | -137 | -137 | -137 | -137 | -137 | -137 | -136 | -137 | -137 | -138 | -139 | -140 | -141 |
| 202106 | LH2-00 | AR | 716 | -125 | -126 | -129 | -131 | -133 | -135 | -137 | -138 | -138 | -138 | -139 | -138 | -138 | -138 | -138 | -137 | -137 | -137 | -138 | -138 | -139 | -139 | -141 | -142 | -143 |
| 202105 | LH2-00 | AR | 741 | -124 | -127 | -130 | -132 | -135 | -137 | -138 | -139 | -140 | -140 | -140 | -140 | -140 | -140 | -139 | -139 | -139 | -139 | -140 | -140 | -141 | -142 | -144 | -145 | -145 |
| 202104 | LH2-00 | AR | 715 | -125 | -127 | -130 | -133 | -137 | -138 | -139 | -141 | -142 | -142 | -142 | -143 | -143 | -143 | -143 | -143 | -144 | -144 | -145 | -146 | -147 | -148 | -147 | -147 | -146 |
| 202103 | LH2-00 | AR | 742 | -125 | -128 | -130 | -133 | -135 | -136 | -138 | -139 | -140 | -140 | -140 | -140 | -140 | -141 | -141 | -141 | -140 | -140 | -141 | -142 | -141 | -143 | -144 | -144 | -143 |
| 202102 | LH2-00 | AR | 651 | -125 | -127 | -128 | -130 | -132 | -133 | -135 | -135 | -136 | -136 | -136 | -136 | -136 | -135 | -135 | -135 | -135 | -135 | -135 | -135 | -135 | -136 | -137 | -138 | -138 |
| 202101 | LH2-00 | AR | 741 | -126 | -128 | -130 | -133 | -135 | -136 | -138 | -140 | -141 | -142 | -142 | -143 | -143 | -144 | -144 | -144 | -145 | -145 | -147 | -147 | -148 | -147 | -146 | -147 | -144 |
| 202012 | LH2-00 | AR | 548 | -125 | -128 | -131 | -133 | -136 | -137 | -139 | -140 | -141 | -142 | -143 | -143 | -143 | -144 | -144 | -145 | -145 | -146 | -147 | -147 | -148 | -148 | -148 | -147 | -145 |
| 202011 | LH2-00 | AR | 692 | -125 | -128 | -131 | -133 | -135 | -136 | -138 | -139 | -141 | -141 | -142 | -142 | -142 | -142 | -143 | -143 | -143 | -143 | -144 | -145 | -146 | -147 | -148 | -148 | -145 |
| 202010 | LH2-00 | AR | 740 | -125 | -128 | -131 | -134 | -137 | -139 | -141 | -142 | -144 | -146 | -147 | -148 | -148 | -149 | -150 | -150 | -151 | -153 | -154 | -155 | -155 | -152 | -153 | -154 | -150 |
| 202009 | LH2-00 | AR | 549 | -125 | -127 | -130 | -134 | -136 | -139 | -140 | -141 | -143 | -143 | -143 | -143 | -144 | -144 | -144 | -144 | -145 | -146 | -147 | -148 | -149 | -147 | -146 | -146 | -146 |
| 202008 | LH2-00 | AR | 741 | -126 | -128 | -130 | -132 | -135 | -137 | -138 | -139 | -140 | -140 | -141 | -140 | -140 | -140 | -140 | -140 | -140 | -141 | -141 | -142 | -142 | -144 | -145 | -147 | -145 |
| 202007 | LH2-00 | AR | 740 | -125 | -127 | -129 | -131 | -134 | -136 | -137 | -138 | -139 | -139 | -139 | -140 | -139 | -139 | -139 | -139 | -139 | -139 | -140 | -140 | -140 | -141 | -143 | -144 | -145 |
| 202006 | LH2-00 | AR | 717 | -126 | -128 | -130 | -134 | -136 | -138 | -139 | -141 | -141 | -142 | -142 | -142 | -142 | -143 | -142 | -142 | -144 | -143 | -144 | -145 | -146 | -147 | -149 | -150 | -150 |
| 202005 | LH2-00 | AR | 732 | -125 | -129 | -131 | -133 | -137 | -138 | -139 | -140 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -143 | -144 | -145 | -146 | -146 | -147 | -147 |
| 202004 | LH2-00 | AR | 712 | -126 | -128 | -131 | -135 | -138 | -140 | -141 | -144 | -145 | -146 | -147 | -148 | -149 | -149 | -149 | -150 | -151 | -153 | -154 | -156 | -154 | -151 | -148 | -148 | -147 |
| 202003 | LH2-00 | AR | 736 | -124 | -127 | -130 | -134 | -136 | -137 | -138 | -140 | -141 | -142 | -142 | -143 | -144 | -144 | -144 | -144 | -144 | -145 | -146 | -147 | -148 | -149 | -149 | -150 | -147 |
| 202002 | LH2-00 | AR | 695 | -125 | -128 | -131 | -133 | -136 | -138 | -139 | -140 | -141 | -143 | -143 | -144 | -144 | -145 | -145 | -146 | -147 | -147 | -149 | -148 | -149 | -149 | -147 | -147 | -146 |
| 202001 | LH2-00 | AR | 736 | -125 | -129 | -131 | -135 | -137 | -138 | -139 | -141 | -143 | -145 | -146 | -148 | -148 | -149 | -150 | -151 | -152 | -153 | -154 | -156 | -154 | -151 | -149 | -148 | -147 |
| 201912 | LH2-00 | AR | 742 | -124 | -127 | -130 | -133 | -136 | -137 | -139 | -140 | -142 | -143 | -144 | -144 | -145 | -145 | -146 | -146 | -147 | -149 | -150 | -151 | -151 | -147 | -146 | -148 | -146 |
| 201911 | LH2-00 | AR | 718 | -125 | -128 | -131 | -134 | -137 | -139 | -141 | -142 | -143 | -144 | -145 | -146 | -147 | -148 | -148 | -148 | -149 | -152 | -153 | -154 | -154 | -153 | -152 | -150 | -146 |
| 201910 | LH2-00 | AR | 729 | -126 | -129 | -133 | -135 | -138 | -140 | -141 | -143 | -144 | -146 | -148 | -148 | -150 | -151 | -151 | -151 | -152 | -153 | -155 | -157 | -157 | -154 | -150 | -150 | -149 |
| 201909 | LH2-00 | AR | 713 | -123 | -127 | -131 | -135 | -138 | -139 | -141 | -143 | -144 | -146 | -148 | -149 | -150 | -151 | -152 | -153 | -153 | -155 | -157 | -158 | -156 | -154 | -151 | -152 | -151 |
| 201908 | LH2-00 | AR | 732 | -126 | -128 | -130 | -132 | -134 | -137 | -139 | -140 | -141 | -141 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -144 | -144 | -146 | -147 | -147 |
| 201907 | LH2-00 | AR | 739 | -130 | -131 | -132 | -135 | -137 | -139 | -141 | -142 | -142 | -143 | -143 | -142 | -142 | -142 | -142 | -142 | -141 | -142 | -141 | -142 | -142 | -143 | -143 | -145 | -144 |
| 201906 | LH2-00 | AR | 669 | -130 | -132 | -135 | -136 | -140 | -142 | -143 | -144 | -145 | -146 | -146 | -146 | -146 | -146 | -145 | -146 | -146 | -146 | -146 | -146 | -147 | -147 | -148 | -149 | -148 |
| 201905 | LH2-00 | AR | 740 | -130 | -132 | -136 | -138 | -141 | -143 | -144 | -144 | -145 | -145 | -145 | -144 | -144 | -144 | -143 | -143 | -143 | -143 | -143 | -143 | -144 | -144 | -144 | -145 | -145 |
| 201904 | LH2-00 | AR | 717 | -129 | -132 | -135 | -137 | -139 | -140 | -141 | -142 | -142 | -142 | -142 | -142 | -142 | -141 | -141 | -141 | -141 | -141 | -141 | -141 | -141 | -142 | -142 | -142 | -143 |
| 201903 | LH2-00 | AR | 740 | -131 | -133 | -136 | -138 | -141 | -142 | -143 | -144 | -144 | -145 | -145 | -145 | -145 | -145 | -145 | -144 | -144 | -144 | -145 | -145 | -145 | -146 | -146 | -146 | -145 |
| 201902 | LH2-00 | AR | 669 | -130 | -132 | -134 | -137 | -140 | -141 | -143 | -144 | -145 | -146 | -146 | -145 | -146 | -146 | -145 | -146 | -146 | -145 | -146 | -147 | -147 | -147 | -147 | -148 | -145 |
| 201901 | LH2-00 | AR | 741 | -131 | -133 | -137 | -139 | -141 | -142 | -144 | -144 | -146 | -146 | -147 | -147 | -147 | -147 | -147 | -147 | -148 | -148 | -148 | -149 | -149 | -149 | -148 | -147 | -147 |
| 201812 | LH2-00 | AR | 743 | -129 | -132 | -134 | -136 | -138 | -139 | -141 | -142 | -142 | -143 | -143 | -143 | -143 | -143 | -143 | -142 | -142 | -142 | -142 | -142 | -143 | -143 | -143 | -143 | -143 |
| 201811 | LH2-00 | AR | 717 | -131 | -133 | -136 | -139 | -141 | -143 | -144 | -145 | -147 | -148 | -148 | -149 | -148 | -149 | -149 | -149 | -149 | -149 | -150 | -149 | -150 | -149 | -148 | -147 | -144 |
| 201810 | LH2-00 | AR | 716 | -131 | -135 | -138 | -141 | -144 | -145 | -147 | -149 | -151 | -152 | -154 | -155 | -155 | -155 | -156 | -155 | -156 | -157 | -158 | -159 | -158 | -155 | -153 | -148 | -147 |
| 201809 | LH2-00 | AR | 718 | -130 | -133 | -137 | -140 | -143 | -144 | -146 | -148 | -149 | -150 | -150 | -149 | -151 | -151 | -151 | -152 | -151 | -152 | -152 | -152 | -152 | -150 | -148 | -147 | -145 |
| 201808 | LH2-00 | AR | 656 | -130 | -132 | -134 | -136 | -139 | -140 | -142 | -143 | -143 | -143 | -143 | -143 | -143 | -143 | -142 | -142 | -142 | -142 | -142 | -142 | -142 | -143 | -144 | -144 | -145 |
| 201807 | LH2-00 | AR | 126 | -139 | -143 | -144 | -148 | -151 | -155 | -156 | -157 | -159 | -159 | -160 | -160 | -162 | -161 | -162 | -161 | -161 | -161 | -161 | -160 | -161 | -161 | -160 | -160 | -159 |