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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 202501 | LHN-00 | AR | 368 | -152 | -153 | -153 | -153 | -154 | -152 | -149 | -146 | -148 | -148 | -148 | -152 | -154 | -155 | -156 | -157 | -160 | -161 | -162 | -160 | -157 | -152 | -149 | -147 | -145 |
| 202412 | LHN-00 | AR | 744 | -152 | -153 | -153 | -154 | -153 | -152 | -148 | -145 | -146 | -146 | -147 | -150 | -152 | -152 | -154 | -156 | -158 | -160 | -160 | -158 | -152 | -148 | -147 | -144 | -141 |
| 202411 | LHN-00 | AR | 720 | -145 | -145 | -146 | -146 | -146 | -146 | -144 | -142 | -143 | -144 | -145 | -148 | -150 | -151 | -152 | -154 | -157 | -159 | -159 | -159 | -156 | -151 | -145 | -144 | -144 |
| 202410 | LHN-00 | AR | 732 | -143 | -143 | -144 | -143 | -143 | -143 | -142 | -140 | -141 | -142 | -143 | -145 | -147 | -148 | -149 | -151 | -153 | -155 | -156 | -155 | -151 | -149 | -146 | -144 | -143 |
| 202409 | LHN-00 | AR | 720 | -143 | -143 | -143 | -143 | -143 | -143 | -141 | -140 | -141 | -141 | -142 | -144 | -146 | -147 | -149 | -151 | -152 | -154 | -156 | -156 | -155 | -151 | -145 | -143 | -142 |
| 202408 | LHN-00 | AR | 205 | -145 | -144 | -143 | -144 | -143 | -143 | -142 | -140 | -140 | -142 | -141 | -144 | -146 | -147 | -148 | -150 | -152 | -154 | -155 | -154 | -149 | -146 | -142 | -143 | -143 |
| 202405 | LHN-00 | AR | 127 | -139 | -149 | -154 | -155 | -159 | -163 | -163 | -167 | -167 | -169 | -171 | -172 | -173 | -174 | -175 | -176 | -177 | -177 | -178 | -176 | -172 | -167 | -159 | -160 | -152 |
| 202404 | LHN-00 | AR | 715 | -142 | -142 | -143 | -143 | -142 | -140 | -136 | -133 | -134 | -134 | -135 | -138 | -141 | -141 | -142 | -144 | -146 | -148 | -148 | -147 | -142 | -137 | -132 | -132 | -133 |
| 202403 | LHN-00 | AR | 744 | -142 | -142 | -143 | -142 | -142 | -140 | -136 | -133 | -134 | -134 | -134 | -138 | -140 | -140 | -142 | -144 | -146 | -148 | -148 | -147 | -144 | -139 | -133 | -133 | -134 |
| 202402 | LHN-00 | AR | 592 | -143 | -144 | -144 | -143 | -143 | -142 | -139 | -135 | -136 | -137 | -137 | -140 | -142 | -143 | -144 | -146 | -148 | -150 | -151 | -150 | -146 | -142 | -138 | -136 | -134 |
| 202401 | LHN-00 | AR | 744 | -139 | -139 | -140 | -140 | -140 | -139 | -136 | -133 | -135 | -135 | -136 | -138 | -141 | -142 | -143 | -145 | -147 | -149 | -150 | -149 | -145 | -139 | -135 | -133 | -132 |
| 202312 | LHN-00 | AR | 741 | -141 | -142 | -142 | -142 | -142 | -141 | -138 | -135 | -135 | -136 | -136 | -139 | -142 | -143 | -144 | -146 | -148 | -150 | -150 | -148 | -144 | -138 | -133 | -133 | -134 |
| 202311 | LHN-00 | AR | 669 | -136 | -137 | -137 | -138 | -138 | -137 | -136 | -133 | -134 | -135 | -136 | -139 | -141 | -142 | -143 | -145 | -146 | -148 | -148 | -148 | -145 | -141 | -137 | -134 | -132 |
| 202310 | LHN-00 | AR | 729 | -130 | -129 | -130 | -130 | -131 | -130 | -130 | -129 | -130 | -131 | -132 | -134 | -136 | -137 | -139 | -141 | -143 | -145 | -146 | -146 | -143 | -139 | -136 | -133 | -132 |
| 202309 | LHN-00 | AR | 713 | -131 | -132 | -132 | -132 | -132 | -132 | -130 | -128 | -129 | -129 | -131 | -133 | -135 | -136 | -138 | -140 | -142 | -144 | -145 | -144 | -141 | -136 | -129 | -128 | -130 |
| 202308 | LHN-00 | AR | 492 | -133 | -133 | -134 | -133 | -133 | -133 | -132 | -129 | -131 | -131 | -131 | -134 | -136 | -137 | -139 | -141 | -143 | -144 | -145 | -144 | -140 | -134 | -130 | -129 | -130 |
| 202307 | LHN-00 | AR | 743 | -133 | -134 | -133 | -134 | -134 | -133 | -130 | -127 | -129 | -129 | -130 | -133 | -135 | -137 | -138 | -140 | -142 | -144 | -144 | -142 | -138 | -133 | -127 | -127 | -127 |
| 202306 | LHN-00 | AR | 684 | -140 | -139 | -139 | -139 | -139 | -137 | -134 | -131 | -132 | -132 | -133 | -136 | -138 | -138 | -140 | -142 | -144 | -146 | -146 | -143 | -139 | -135 | -130 | -129 | -130 |
| 202305 | LHN-00 | AR | 742 | -140 | -141 | -141 | -141 | -141 | -139 | -135 | -132 | -133 | -133 | -134 | -137 | -140 | -140 | -141 | -143 | -145 | -148 | -148 | -145 | -140 | -135 | -132 | -131 | -130 |
| 202304 | LHN-00 | AR | 716 | -144 | -144 | -143 | -143 | -142 | -140 | -137 | -133 | -135 | -135 | -135 | -138 | -140 | -140 | -142 | -144 | -146 | -148 | -149 | -146 | -141 | -136 | -134 | -133 | -132 |
| 202303 | LHN-00 | AR | 699 | -144 | -144 | -144 | -144 | -144 | -142 | -138 | -134 | -135 | -136 | -136 | -139 | -142 | -142 | -143 | -145 | -147 | -149 | -150 | -148 | -143 | -138 | -133 | -133 | -134 |
| 202302 | LHN-00 | AR | 667 | -143 | -143 | -143 | -143 | -143 | -141 | -137 | -134 | -135 | -136 | -136 | -139 | -142 | -142 | -142 | -144 | -147 | -149 | -149 | -148 | -144 | -141 | -136 | -133 | -132 |
| 202301 | LHN-00 | AR | 744 | -145 | -145 | -145 | -145 | -145 | -144 | -140 | -136 | -137 | -137 | -138 | -141 | -143 | -143 | -144 | -146 | -148 | -151 | -151 | -150 | -148 | -142 | -137 | -134 | -135 |
| 202212 | LHN-00 | AR | 742 | -143 | -143 | -144 | -144 | -143 | -142 | -138 | -135 | -136 | -136 | -137 | -140 | -142 | -142 | -143 | -145 | -148 | -150 | -150 | -150 | -148 | -143 | -137 | -135 | -134 |
| 202211 | LHN-00 | AR | 718 | -135 | -136 | -136 | -137 | -137 | -137 | -135 | -133 | -134 | -134 | -135 | -138 | -140 | -141 | -142 | -144 | -146 | -147 | -148 | -148 | -145 | -141 | -136 | -134 | -132 |
| 202210 | LHN-00 | AR | 744 | -130 | -130 | -131 | -130 | -130 | -130 | -130 | -129 | -130 | -130 | -132 | -134 | -136 | -137 | -138 | -140 | -142 | -144 | -145 | -145 | -143 | -139 | -134 | -130 | -133 |
| 202209 | LHN-00 | AR | 720 | -129 | -130 | -130 | -130 | -130 | -130 | -129 | -128 | -129 | -129 | -130 | -132 | -134 | -135 | -137 | -138 | -140 | -142 | -143 | -143 | -139 | -135 | -130 | -129 | -128 |
| 202208 | LHN-00 | AR | 718 | -131 | -131 | -131 | -131 | -131 | -131 | -130 | -128 | -129 | -130 | -130 | -132 | -134 | -135 | -136 | -139 | -140 | -142 | -143 | -143 | -138 | -134 | -129 | -128 | -129 |
| 202207 | LHN-00 | AR | 708 | -132 | -132 | -132 | -132 | -132 | -131 | -130 | -127 | -128 | -129 | -129 | -132 | -134 | -135 | -136 | -138 | -140 | -142 | -143 | -142 | -139 | -134 | -128 | -127 | -129 |
| 202206 | LHN-00 | AR | 720 | -135 | -136 | -136 | -136 | -136 | -135 | -132 | -129 | -130 | -130 | -131 | -134 | -137 | -137 | -139 | -140 | -143 | -144 | -145 | -143 | -140 | -135 | -130 | -127 | -128 |
| 202205 | LHN-00 | AR | 744 | -141 | -141 | -140 | -141 | -140 | -138 | -134 | -131 | -132 | -132 | -133 | -136 | -138 | -139 | -140 | -142 | -145 | -146 | -147 | -144 | -139 | -135 | -131 | -130 | -130 |
| 202204 | LHN-00 | AR | 716 | -144 | -144 | -143 | -143 | -142 | -141 | -137 | -133 | -135 | -135 | -135 | -138 | -141 | -141 | -142 | -144 | -146 | -148 | -149 | -147 | -143 | -138 | -134 | -133 | -132 |
| 202203 | LHN-00 | AR | 714 | -143 | -143 | -144 | -143 | -143 | -141 | -138 | -135 | -136 | -136 | -136 | -139 | -142 | -142 | -143 | -145 | -147 | -148 | -149 | -148 | -145 | -140 | -135 | -134 | -135 |
| 202202 | LHN-00 | AR | 672 | -143 | -143 | -144 | -143 | -143 | -141 | -137 | -133 | -134 | -135 | -136 | -138 | -141 | -142 | -143 | -145 | -148 | -149 | -150 | -148 | -145 | -138 | -133 | -131 | -132 |
| 202201 | LHN-00 | AR | 720 | -143 | -145 | -144 | -144 | -145 | -144 | -140 | -137 | -138 | -138 | -139 | -142 | -145 | -145 | -145 | -148 | -150 | -151 | -152 | -152 | -148 | -143 | -138 | -135 | -135 |
| 202112 | LHN-00 | AR | 744 | -141 | -142 | -142 | -143 | -143 | -142 | -138 | -135 | -136 | -136 | -137 | -140 | -143 | -143 | -144 | -146 | -148 | -150 | -150 | -149 | -146 | -142 | -137 | -134 | -133 |
| 202111 | LHN-00 | AR | 719 | -136 | -136 | -137 | -137 | -137 | -136 | -134 | -132 | -133 | -133 | -135 | -138 | -140 | -141 | -143 | -144 | -147 | -149 | -150 | -149 | -147 | -142 | -136 | -134 | -133 |
| 202110 | LHN-00 | AR | 744 | -131 | -131 | -131 | -131 | -131 | -131 | -130 | -129 | -129 | -130 | -131 | -133 | -135 | -136 | -137 | -139 | -141 | -143 | -145 | -145 | -143 | -139 | -133 | -132 | -132 |
| 202109 | LHN-00 | AR | 328 | -131 | -131 | -131 | -131 | -131 | -131 | -130 | -128 | -129 | -130 | -130 | -133 | -134 | -136 | -137 | -138 | -140 | -142 | -143 | -143 | -140 | -135 | -132 | -129 | -127 |
| 202104 | LHN-00 | AR | 495 | -143 | -144 | -144 | -143 | -144 | -141 | -136 | -132 | -134 | -134 | -134 | -138 | -140 | -141 | -142 | -144 | -146 | -149 | -149 | -148 | -145 | -142 | -134 | -132 | -132 |
| 202103 | LHN-00 | AR | 743 | -145 | -145 | -146 | -146 | -146 | -143 | -139 | -135 | -136 | -136 | -137 | -140 | -142 | -143 | -143 | -145 | -147 | -149 | -150 | -149 | -146 | -141 | -136 | -135 | -135 |
| 202102 | LHN-00 | AR | 618 | -146 | -146 | -147 | -145 | -145 | -142 | -138 | -134 | -135 | -135 | -135 | -139 | -141 | -141 | -142 | -144 | -146 | -148 | -148 | -146 | -141 | -136 | -134 | -133 | -131 |
| 202101 | LHN-00 | AR | 744 | -145 | -146 | -146 | -146 | -145 | -143 | -138 | -134 | -135 | -135 | -136 | -139 | -142 | -142 | -143 | -145 | -147 | -149 | -150 | -148 | -144 | -140 | -133 | -130 | -131 |
| 202012 | LHN-00 | AR | 744 | -146 | -148 | -148 | -146 | -146 | -144 | -139 | -135 | -136 | -136 | -137 | -140 | -143 | -143 | -144 | -146 | -148 | -149 | -150 | -148 | -144 | -140 | -135 | -133 | -130 |
| 202011 | LHN-00 | AR | 720 | -144 | -145 | -144 | -145 | -145 | -142 | -137 | -134 | -135 | -135 | -135 | -139 | -141 | -142 | -142 | -145 | -147 | -148 | -149 | -148 | -146 | -142 | -135 | -132 | -134 |
| 202010 | LHN-00 | AR | 744 | -143 | -143 | -144 | -143 | -142 | -139 | -135 | -131 | -132 | -132 | -133 | -136 | -139 | -140 | -141 | -143 | -146 | -147 | -147 | -145 | -141 | -137 | -132 | -130 | -132 |
| 202009 | LHN-00 | AR | 720 | -141 | -140 | -140 | -140 | -140 | -138 | -134 | -130 | -131 | -131 | -132 | -135 | -137 | -138 | -139 | -140 | -143 | -144 | -144 | -142 | -137 | -133 | -128 | -127 | -127 |
| 202008 | LHN-00 | AR | 588 | -138 | -138 | -139 | -138 | -138 | -136 | -132 | -129 | -130 | -129 | -131 | -134 | -136 | -137 | -139 | -141 | -143 | -144 | -144 | -143 | -138 | -132 | -125 | -124 | -127 |
| 202007 | LHN-00 | AR | 681 | -136 | -136 | -136 | -136 | -136 | -134 | -130 | -126 | -127 | -127 | -129 | -132 | -134 | -135 | -137 | -139 | -141 | -142 | -142 | -138 | -132 | -130 | -124 | -125 | -123 |
| 202006 | LHN-00 | AR | 683 | -140 | -141 | -141 | -140 | -140 | -138 | -133 | -129 | -130 | -131 | -132 | -135 | -138 | -138 | -139 | -142 | -144 | -145 | -145 | -144 | -139 | -134 | -127 | -127 | -130 |
| 202005 | LHN-00 | AR | 744 | -142 | -142 | -142 | -141 | -141 | -139 | -134 | -130 | -132 | -131 | -132 | -135 | -137 | -138 | -140 | -142 | -144 | -146 | -146 | -144 | -139 | -134 | -128 | -130 | -130 |
| 202004 | LHN-00 | AR | 676 | -143 | -143 | -144 | -143 | -142 | -140 | -135 | -132 | -133 | -133 | -133 | -136 | -139 | -139 | -140 | -142 | -145 | -146 | -147 | -146 | -142 | -136 | -131 | -131 | -131 |
| 202003 | LHN-00 | AR | 744 | -146 | -146 | -147 | -146 | -145 | -143 | -139 | -134 | -135 | -135 | -136 | -139 | -142 | -142 | -143 | -146 | -148 | -150 | -150 | -150 | -147 | -142 | -135 | -133 | -134 |
| 202002 | LHN-00 | AR | 639 | -145 | -146 | -145 | -146 | -145 | -143 | -138 | -134 | -135 | -135 | -136 | -139 | -142 | -142 | -143 | -145 | -148 | -149 | -150 | -149 | -145 | -140 | -133 | -132 | -133 |
| 202001 | LHN-00 | AR | 742 | -146 | -146 | -147 | -146 | -145 | -143 | -138 | -134 | -136 | -136 | -136 | -139 | -142 | -142 | -142 | -145 | -147 | -149 | -150 | -149 | -146 | -142 | -136 | -134 | -133 |
| 201912 | LHN-00 | AR | 744 | -145 | -145 | -146 | -145 | -145 | -143 | -138 | -133 | -135 | -135 | -136 | -139 | -141 | -141 | -142 | -144 | -147 | -148 | -149 | -148 | -143 | -140 | -135 | -133 | -134 |
| 201911 | LHN-00 | AR | 720 | -145 | -146 | -145 | -145 | -145 | -142 | -138 | -134 | -135 | -135 | -136 | -139 | -142 | -142 | -143 | -145 | -147 | -149 | -149 | -148 | -145 | -139 | -133 | -131 | -133 |
| 201910 | LHN-00 | AR | 744 | -144 | -144 | -144 | -144 | -143 | -141 | -135 | -131 | -133 | -133 | -134 | -137 | -140 | -141 | -142 | -144 | -146 | -148 | -148 | -146 | -140 | -135 | -132 | -132 | -134 |
| 201909 | LHN-00 | AR | 720 | -143 | -143 | -143 | -143 | -142 | -139 | -134 | -131 | -132 | -132 | -133 | -136 | -139 | -139 | -140 | -142 | -145 | -146 | -146 | -144 | -139 | -134 | -130 | -129 | -130 |
| 201908 | LHN-00 | AR | 744 | -137 | -138 | -139 | -138 | -138 | -136 | -132 | -128 | -129 | -129 | -131 | -134 | -136 | -137 | -139 | -140 | -143 | -144 | -144 | -142 | -137 | -132 | -125 | -125 | -127 |
| 201907 | LHN-00 | AR | 732 | -139 | -138 | -138 | -138 | -138 | -135 | -131 | -127 | -129 | -129 | -130 | -133 | -135 | -136 | -137 | -140 | -142 | -143 | -143 | -140 | -134 | -130 | -124 | -125 | -125 |
| 201906 | LHN-00 | AR | 696 | -141 | -141 | -141 | -141 | -140 | -139 | -134 | -130 | -131 | -131 | -132 | -135 | -138 | -139 | -140 | -142 | -144 | -145 | -146 | -144 | -139 | -135 | -128 | -128 | -128 |
| 201905 | LHN-00 | AR | 721 | -142 | -143 | -143 | -143 | -142 | -140 | -136 | -132 | -134 | -133 | -133 | -137 | -139 | -140 | -141 | -143 | -145 | -147 | -148 | -146 | -141 | -136 | -130 | -130 | -131 |
| 201904 | LHN-00 | AR | 702 | -142 | -143 | -143 | -143 | -142 | -140 | -135 | -132 | -133 | -132 | -133 | -136 | -139 | -139 | -140 | -143 | -145 | -147 | -147 | -144 | -138 | -135 | -132 | -133 | -131 |
| 201903 | LHN-00 | AR | 744 | -146 | -146 | -146 | -146 | -145 | -143 | -138 | -134 | -135 | -135 | -136 | -139 | -141 | -141 | -142 | -145 | -147 | -149 | -149 | -147 | -143 | -139 | -133 | -133 | -133 |
| 201902 | LHN-00 | AR | 655 | -147 | -148 | -147 | -147 | -147 | -144 | -139 | -136 | -137 | -137 | -137 | -140 | -142 | -143 | -144 | -146 | -148 | -150 | -151 | -149 | -145 | -140 | -135 | -132 | -135 |
| 201901 | LHN-00 | AR | 744 | -147 | -148 | -148 | -147 | -147 | -144 | -139 | -135 | -136 | -136 | -136 | -139 | -142 | -142 | -143 | -145 | -148 | -150 | -150 | -148 | -143 | -140 | -135 | -134 | -133 |
| 201812 | LHN-00 | AR | 744 | -146 | -146 | -146 | -145 | -146 | -143 | -139 | -135 | -136 | -136 | -137 | -139 | -142 | -142 | -143 | -145 | -147 | -149 | -149 | -148 | -145 | -141 | -134 | -133 | -135 |
| 201811 | LHN-00 | AR | 709 | -147 | -147 | -147 | -147 | -147 | -144 | -140 | -135 | -137 | -137 | -137 | -140 | -143 | -143 | -145 | -146 | -149 | -150 | -151 | -149 | -146 | -142 | -135 | -135 | -136 |
| 201810 | LHN-00 | AR | 718 | -145 | -145 | -145 | -144 | -144 | -141 | -136 | -132 | -133 | -133 | -135 | -137 | -140 | -141 | -142 | -144 | -146 | -148 | -148 | -147 | -142 | -137 | -132 | -133 | -134 |
| 201809 | LHN-00 | AR | 676 | -142 | -143 | -143 | -142 | -141 | -138 | -134 | -131 | -132 | -132 | -133 | -136 | -138 | -139 | -140 | -142 | -144 | -146 | -146 | -143 | -139 | -135 | -130 | -129 | -130 |
| 201808 | LHN-00 | AR | 703 | -142 | -142 | -142 | -141 | -141 | -138 | -134 | -130 | -132 | -132 | -132 | -135 | -138 | -138 | -140 | -142 | -144 | -145 | -145 | -143 | -138 | -133 | -128 | -128 | -128 |
| 201807 | LHN-00 | AR | 496 | -141 | -139 | -140 | -140 | -139 | -137 | -132 | -129 | -130 | -131 | -132 | -134 | -137 | -137 | -139 | -141 | -144 | -145 | -145 | -142 | -136 | -132 | -127 | -128 | -128 |
| 201806 | LHN-00 | AR | 248 | -142 | -142 | -143 | -142 | -143 | -140 | -136 | -131 | -133 | -134 | -134 | -136 | -139 | -140 | -140 | -142 | -145 | -146 | -146 | -143 | -138 | -133 | -129 | -128 | -125 |
| 201804 | LHN-00 | AR | 216 | -145 | -144 | -144 | -145 | -144 | -140 | -136 | -133 | -134 | -133 | -134 | -138 | -140 | -141 | -142 | -144 | -146 | -148 | -149 | -148 | -144 | -138 | -136 | -134 | -133 |
| 201803 | LHN-00 | AR | 453 | -148 | -148 | -148 | -147 | -147 | -145 | -139 | -135 | -136 | -136 | -136 | -139 | -142 | -142 | -143 | -145 | -147 | -149 | -150 | -149 | -145 | -140 | -134 | -133 | -133 |
| 201802 | LHN-00 | AR | 56 | 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 |