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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 202404 | LHN | AR | 480 | -26 | -27 | -26 | -26 | -26 | -27 | -27 | -28 | -28 | -29 | -30 | -32 | -34 | -37 | -39 | -42 | -45 | -48 | -51 | -54 | -56 | -56 | -57 | -58 | -58 |
| 202403 | LHN | AR | 716 | -26 | -26 | -26 | -26 | -26 | -26 | -27 | -27 | -28 | -29 | -30 | -32 | -34 | -36 | -39 | -42 | -45 | -48 | -51 | -54 | -56 | -56 | -57 | -57 | -55 |
| 202402 | LHN | AR | 670 | -25 | -26 | -25 | -25 | -25 | -25 | -25 | -25 | -26 | -27 | -29 | -31 | -33 | -36 | -39 | -41 | -44 | -47 | -50 | -53 | -54 | -55 | -55 | -56 | -56 |
| 202401 | LHN | AR | 718 | -26 | -25 | -25 | -25 | -25 | -25 | -25 | -25 | -25 | -26 | -28 | -30 | -31 | -34 | -36 | -39 | -41 | -44 | -47 | -50 | -53 | -54 | -55 | -56 | -57 |
| 202312 | LHN | AR | 731 | -27 | -27 | -27 | -28 | -28 | -28 | -29 | -29 | -29 | -30 | -31 | -33 | -36 | -38 | -41 | -44 | -46 | -49 | -52 | -55 | -56 | -55 | -54 | -55 | -54 |
| 202311 | LHN | 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 |
| 202310 | LHN | AR | 538 | -25 | -25 | -24 | -24 | -24 | -25 | -24 | -25 | -25 | -26 | -27 | -29 | -31 | -34 | -37 | -39 | -43 | -46 | -48 | -52 | -54 | -55 | -55 | -56 | -57 |
| 202309 | LHN | AR | 712 | -25 | -26 | -26 | -25 | -26 | -26 | -27 | -26 | -27 | -27 | -29 | -30 | -32 | -35 | -38 | -41 | -45 | -48 | -51 | -54 | -56 | -57 | -57 | -58 | -59 |
| 202308 | LHN | AR | 358 | -26 | -27 | -27 | -27 | -27 | -27 | -27 | -27 | -27 | -28 | -29 | -30 | -33 | -36 | -38 | -41 | -44 | -48 | -51 | -54 | -57 | -59 | -62 | -63 | -61 |
| 202307 | LHN | AR | 736 | -26 | -25 | -26 | -27 | -27 | -28 | -28 | -29 | -30 | -31 | -32 | -34 | -36 | -39 | -41 | -44 | -47 | -51 | -54 | -57 | -60 | -61 | -62 | -64 | -63 |
| 202306 | LHN | AR | 718 | -27 | -28 | -28 | -28 | -28 | -29 | -29 | -30 | -30 | -31 | -32 | -35 | -36 | -40 | -42 | -45 | -48 | -51 | -54 | -58 | -60 | -61 | -63 | -65 | -64 |
| 202305 | LHN | AR | 668 | -24 | -23 | -24 | -24 | -24 | -24 | -25 | -25 | -26 | -27 | -29 | -30 | -32 | -35 | -38 | -41 | -44 | -47 | -49 | -52 | -55 | -57 | -59 | -61 | -60 |
| 202304 | LHN | AR | 711 | -26 | -26 | -26 | -26 | -26 | -26 | -27 | -27 | -27 | -28 | -30 | -31 | -34 | -36 | -38 | -42 | -44 | -47 | -50 | -53 | -55 | -56 | -57 | -58 | -60 |
| 202303 | LHN | AR | 96 | 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 |
| 202212 | LHN | AR | 538 | -23 | -23 | -22 | -22 | -22 | -22 | -21 | -22 | -22 | -23 | -24 | -25 | -27 | -29 | -32 | -35 | -37 | -40 | -43 | -46 | -49 | -50 | -51 | -53 | -54 |
| 202211 | LHN | AR | 624 | -22 | -22 | -22 | -22 | -22 | -23 | -23 | -23 | -24 | -25 | -26 | -28 | -30 | -32 | -34 | -37 | -40 | -43 | -45 | -48 | -51 | -52 | -52 | -54 | -55 |
| 202210 | LHN | AR | 143 | -23 | -23 | -25 | -23 | -24 | -24 | -24 | -25 | -27 | -29 | -31 | -33 | -35 | -37 | -39 | -43 | -46 | -49 | -52 | -54 | -55 | -57 | -57 | -56 | -56 |
| 202209 | LHN | AR | 334 | -25 | -26 | -27 | -27 | -27 | -27 | -27 | -28 | -28 | -29 | -30 | -32 | -34 | -37 | -40 | -43 | -46 | -49 | -52 | -55 | -57 | -58 | -59 | -59 | -60 |
| 202208 | LHN | AR | 716 | -26 | -27 | -27 | -28 | -28 | -28 | -29 | -30 | -31 | -32 | -33 | -35 | -37 | -40 | -43 | -46 | -48 | -52 | -54 | -57 | -59 | -60 | -62 | -65 | -64 |
| 202207 | LHN | AR | 601 | -28 | -29 | -29 | -28 | -30 | -29 | -30 | -30 | -31 | -32 | -34 | -35 | -39 | -41 | -44 | -46 | -50 | -53 | -56 | -58 | -60 | -61 | -63 | -65 | -62 |
| 202206 | LHN | AR | 713 | -123 | -125 | -127 | -129 | -131 | -132 | -134 | -136 | -137 | -139 | -140 | -142 | -143 | -145 | -147 | -148 | -150 | -151 | -153 | -154 | -155 | -155 | -155 | -155 | -153 |
| 202204 | LHN | AR | 401 | -122 | -123 | -125 | -126 | -128 | -129 | -131 | -133 | -134 | -135 | -137 | -139 | -141 | -142 | -144 | -146 | -147 | -149 | -151 | -152 | -152 | -152 | -150 | -150 | -149 |
| 202203 | LHN | AR | 742 | -127 | -128 | -129 | -130 | -132 | -134 | -135 | -136 | -137 | -139 | -140 | -142 | -144 | -146 | -147 | -148 | -149 | -151 | -152 | -154 | -154 | -153 | -151 | -152 | -149 |
| 202202 | LHN | AR | 672 | -127 | -129 | -130 | -131 | -133 | -133 | -135 | -135 | -137 | -138 | -139 | -140 | -141 | -143 | -145 | -146 | -147 | -147 | -149 | -149 | -148 | -148 | -149 | -149 | -147 |
| 202201 | LHN | AR | 659 | -123 | -124 | -126 | -127 | -128 | -130 | -131 | -133 | -134 | -136 | -138 | -138 | -140 | -141 | -143 | -143 | -145 | -146 | -148 | -149 | -150 | -148 | -148 | -149 | -148 |
| 202112 | LHN | AR | 697 | -121 | -124 | -124 | -126 | -127 | -128 | -130 | -131 | -132 | -133 | -135 | -136 | -137 | -139 | -141 | -142 | -143 | -144 | -145 | -147 | -149 | -147 | -146 | -146 | -148 |
| 202111 | LHN | AR | 718 | -120 | -122 | -123 | -124 | -125 | -127 | -128 | -128 | -130 | -131 | -133 | -134 | -135 | -136 | -138 | -140 | -140 | -142 | -143 | -145 | -147 | -147 | -147 | -147 | -148 |
| 202110 | LHN | AR | 743 | -124 | -126 | -128 | -130 | -131 | -132 | -134 | -135 | -137 | -138 | -140 | -141 | -143 | -145 | -147 | -148 | -149 | -151 | -153 | -155 | -155 | -152 | -150 | -150 | -150 |
| 202109 | LHN | AR | 702 | -122 | -124 | -125 | -126 | -128 | -131 | -132 | -134 | -135 | -137 | -138 | -140 | -141 | -143 | -145 | -146 | -148 | -149 | -150 | -152 | -152 | -151 | -151 | -152 | -150 |
| 202108 | LHN | AR | 677 | -124 | -127 | -128 | -131 | -132 | -134 | -135 | -137 | -138 | -140 | -142 | -144 | -145 | -147 | -148 | -150 | -151 | -153 | -155 | -156 | -157 | -157 | -157 | -157 | -154 |
| 202107 | LHN | AR | 742 | -124 | -126 | -128 | -129 | -130 | -132 | -134 | -135 | -137 | -138 | -139 | -141 | -143 | -145 | -146 | -148 | -149 | -151 | -152 | -154 | -154 | -155 | -155 | -157 | -154 |
| 202106 | LHN | AR | 716 | -125 | -127 | -128 | -130 | -132 | -134 | -135 | -137 | -139 | -140 | -142 | -143 | -145 | -147 | -148 | -150 | -151 | -152 | -154 | -155 | -155 | -155 | -156 | -156 | -154 |
| 202105 | LHN | AR | 739 | -125 | -126 | -129 | -130 | -132 | -133 | -135 | -136 | -138 | -139 | -141 | -143 | -145 | -146 | -148 | -149 | -150 | -152 | -153 | -154 | -154 | -154 | -153 | -152 | -151 |
| 202104 | LHN | AR | 716 | -124 | -126 | -128 | -129 | -131 | -132 | -134 | -135 | -137 | -139 | -141 | -142 | -144 | -145 | -147 | -148 | -150 | -151 | -152 | -154 | -154 | -154 | -153 | -152 | -150 |
| 202103 | LHN | AR | 266 | -122 | -125 | -126 | -127 | -129 | -131 | -133 | -135 | -137 | -139 | -141 | -142 | -144 | -145 | -146 | -148 | -150 | -152 | -152 | -153 | -154 | -153 | -153 | -152 | -150 |
| 202101 | LHN | AR | 122 | -123 | -124 | -125 | -126 | -127 | -128 | -130 | -131 | -133 | -135 | -135 | -137 | -139 | -140 | -141 | -143 | -144 | -146 | -147 | -149 | -149 | -149 | -150 | -147 | -138 |
| 202012 | LHN | AR | 733 | -122 | -123 | -124 | -125 | -126 | -127 | -128 | -129 | -130 | -132 | -133 | -134 | -136 | -137 | -139 | -140 | -141 | -143 | -143 | -145 | -147 | -147 | -147 | -147 | -145 |
| 202011 | LHN | AR | 717 | -121 | -123 | -125 | -126 | -128 | -129 | -130 | -133 | -134 | -136 | -138 | -139 | -140 | -142 | -143 | -145 | -146 | -147 | -149 | -150 | -150 | -149 | -148 | -148 | -148 |
| 202010 | LHN | AR | 679 | -123 | -123 | -125 | -126 | -126 | -128 | -129 | -130 | -132 | -133 | -134 | -135 | -137 | -138 | -139 | -141 | -142 | -143 | -145 | -146 | -148 | -149 | -150 | -150 | -150 |
| 202009 | LHN | AR | 716 | -124 | -126 | -127 | -128 | -130 | -132 | -132 | -134 | -136 | -137 | -139 | -140 | -142 | -144 | -145 | -147 | -148 | -149 | -151 | -153 | -153 | -153 | -153 | -153 | -152 |
| 202008 | LHN | AR | 725 | -123 | -125 | -127 | -128 | -131 | -132 | -134 | -136 | -137 | -139 | -140 | -142 | -144 | -145 | -147 | -149 | -151 | -152 | -153 | -155 | -157 | -157 | -157 | -156 | -155 |
| 202007 | LHN | AR | 740 | -122 | -124 | -126 | -129 | -131 | -133 | -134 | -136 | -138 | -140 | -141 | -143 | -145 | -147 | -148 | -150 | -152 | -154 | -155 | -157 | -157 | -157 | -158 | -158 | -156 |
| 202006 | LHN | AR | 711 | -122 | -124 | -125 | -128 | -130 | -133 | -135 | -137 | -138 | -140 | -142 | -144 | -146 | -147 | -149 | -150 | -151 | -153 | -154 | -156 | -157 | -156 | -157 | -157 | -156 |
| 202005 | LHN | AR | 741 | -120 | -123 | -124 | -126 | -128 | -129 | -131 | -132 | -134 | -135 | -137 | -139 | -139 | -141 | -142 | -144 | -146 | -147 | -149 | -150 | -151 | -152 | -152 | -151 | -150 |
| 202004 | LHN | AR | 717 | -121 | -123 | -125 | -126 | -128 | -129 | -131 | -132 | -134 | -135 | -136 | -137 | -138 | -140 | -141 | -142 | -144 | -145 | -147 | -148 | -149 | -149 | -148 | -148 | -147 |
| 202003 | LHN | AR | 743 | -120 | -120 | -123 | -124 | -127 | -129 | -131 | -132 | -134 | -135 | -137 | -139 | -140 | -142 | -143 | -145 | -146 | -147 | -149 | -150 | -151 | -151 | -151 | -151 | -149 |
| 202002 | LHN | AR | 561 | -120 | -121 | -123 | -124 | -126 | -128 | -130 | -132 | -134 | -136 | -138 | -140 | -141 | -143 | -144 | -146 | -147 | -148 | -150 | -151 | -152 | -150 | -150 | -150 | -148 |
| 202001 | LHN | AR | 253 | -119 | -120 | -123 | -125 | -125 | -127 | -128 | -130 | -133 | -134 | -135 | -137 | -139 | -141 | -142 | -143 | -144 | -145 | -147 | -147 | -148 | -148 | -148 | -148 | -146 |
| 201912 | LHN | AR | 619 | -119 | -121 | -122 | -124 | -125 | -126 | -127 | -129 | -130 | -132 | -133 | -134 | -135 | -137 | -138 | -140 | -141 | -142 | -143 | -145 | -146 | -146 | -145 | -146 | -145 |
| 201911 | LHN | AR | 718 | -120 | -121 | -122 | -123 | -124 | -126 | -127 | -128 | -130 | -131 | -132 | -133 | -135 | -136 | -137 | -138 | -140 | -141 | -142 | -144 | -145 | -146 | -146 | -147 | -147 |
| 201910 | LHN | AR | 741 | -124 | -125 | -127 | -130 | -131 | -132 | -134 | -135 | -136 | -138 | -139 | -141 | -142 | -143 | -145 | -147 | -148 | -149 | -150 | -152 | -152 | -150 | -149 | -149 | -149 |
| 201909 | LHN | AR | 709 | -124 | -125 | -126 | -128 | -129 | -131 | -132 | -134 | -135 | -137 | -138 | -140 | -141 | -142 | -144 | -145 | -146 | -148 | -149 | -150 | -152 | -151 | -152 | -151 | -150 |
| 201908 | LHN | AR | 736 | -126 | -128 | -129 | -131 | -132 | -134 | -135 | -137 | -139 | -140 | -141 | -142 | -144 | -146 | -147 | -149 | -150 | -152 | -154 | -155 | -156 | -156 | -156 | -155 | -154 |
| 201907 | LHN | AR | 706 | -123 | -126 | -127 | -129 | -130 | -133 | -135 | -136 | -138 | -140 | -141 | -144 | -145 | -145 | -147 | -148 | -150 | -151 | -153 | -154 | -154 | -153 | -154 | -157 | -154 |
| 201906 | LHN | AR | 689 | -132 | -133 | -134 | -136 | -138 | -140 | -142 | -143 | -145 | -146 | -148 | -150 | -151 | -152 | -154 | -155 | -156 | -156 | -157 | -158 | -158 | -157 | -157 | -158 | -155 |
| 201905 | LHN | AR | 737 | -130 | -131 | -133 | -134 | -136 | -138 | -140 | -142 | -143 | -145 | -146 | -148 | -149 | -151 | -152 | -153 | -155 | -156 | -158 | -159 | -158 | -156 | -155 | -155 | -154 |
| 201904 | LHN | AR | 713 | -129 | -130 | -131 | -133 | -134 | -136 | -137 | -139 | -140 | -142 | -143 | -144 | -146 | -147 | -148 | -150 | -151 | -153 | -154 | -154 | -155 | -154 | -153 | -153 | -151 |
| 201903 | LHN | AR | 742 | -135 | -137 | -139 | -139 | -140 | -141 | -143 | -144 | -145 | -147 | -148 | -148 | -149 | -151 | -153 | -154 | -155 | -156 | -157 | -158 | -157 | -154 | -153 | -154 | -151 |
| 201902 | LHN | AR | 669 | -132 | -134 | -135 | -136 | -137 | -138 | -139 | -141 | -142 | -143 | -144 | -145 | -146 | -148 | -149 | -151 | -152 | -153 | -155 | -156 | -155 | -153 | -152 | -153 | -150 |
| 201901 | LHN | AR | 743 | -126 | -128 | -129 | -130 | -132 | -133 | -134 | -136 | -136 | -138 | -139 | -140 | -141 | -142 | -144 | -145 | -147 | -149 | -150 | -152 | -153 | -151 | -150 | -149 | -149 |
| 201812 | LHN | AR | 725 | -126 | -127 | -129 | -130 | -132 | -133 | -134 | -135 | -137 | -138 | -140 | -141 | -143 | -143 | -145 | -147 | -148 | -150 | -151 | -152 | -152 | -151 | -150 | -149 | -148 |
| 201811 | LHN | AR | 708 | -126 | -127 | -129 | -130 | -131 | -132 | -134 | -136 | -136 | -138 | -139 | -141 | -142 | -142 | -144 | -145 | -146 | -148 | -150 | -151 | -152 | -151 | -150 | -151 | -150 |
| 201810 | LHN | AR | 702 | -127 | -128 | -130 | -131 | -132 | -133 | -136 | -137 | -138 | -140 | -142 | -143 | -144 | -146 | -147 | -149 | -150 | -151 | -153 | -154 | -155 | -153 | -152 | -150 | -149 |
| 201809 | LHN | AR | 678 | -132 | -133 | -134 | -137 | -138 | -140 | -142 | -143 | -145 | -147 | -149 | -150 | -152 | -154 | -155 | -156 | -157 | -159 | -160 | -161 | -159 | -156 | -156 | -154 | -153 |
| 201808 | LHN | AR | 661 | -132 | -134 | -136 | -138 | -139 | -141 | -143 | -145 | -147 | -149 | -150 | -152 | -154 | -156 | -157 | -159 | -160 | -162 | -163 | -164 | -162 | -160 | -159 | -160 | -158 |
| 201807 | LHN | AR | 615 | -130 | -132 | -134 | -136 | -138 | -140 | -142 | -143 | -145 | -147 | -149 | -150 | -152 | -154 | -155 | -157 | -159 | -160 | -161 | -162 | -160 | -159 | -159 | -159 | -156 |
| 201806 | LHN | AR | 675 | -132 | -134 | -135 | -137 | -138 | -140 | -142 | -143 | -145 | -147 | -148 | -150 | -151 | -153 | -154 | -156 | -157 | -158 | -160 | -160 | -160 | -158 | -158 | -158 | -156 |
| 201805 | LHN | AR | 736 | -132 | -133 | -135 | -137 | -138 | -140 | -141 | -142 | -144 | -145 | -147 | -148 | -150 | -151 | -153 | -155 | -156 | -158 | -158 | -159 | -159 | -158 | -158 | -158 | -154 |
| 201804 | LHN | AR | 709 | -129 | -131 | -132 | -133 | -135 | -136 | -137 | -138 | -140 | -141 | -143 | -144 | -146 | -147 | -148 | -149 | -151 | -152 | -154 | -155 | -155 | -154 | -153 | -153 | -151 |
| 201803 | LHN | AR | 742 | -127 | -128 | -129 | -130 | -131 | -132 | -134 | -135 | -136 | -138 | -139 | -140 | -141 | -142 | -144 | -145 | -147 | -148 | -150 | -151 | -152 | -149 | -149 | -148 | -148 |
| 201802 | LHN | AR | 59 | 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 |