Sirens and emergency vehicle noise in Los Angeles
Updated
Modeled estimates for general information only — not measurements, not a guarantee, and not for legal, medical or real-estate decisions.
Quiet LA can add an estimate of siren noise from Los Angeles Fire Department (LAFD) fire engines and ambulances to the map. It is controlled by the Fire engines and Ambulances switches (on by default), and it covers the City of Los Angeles only. It is a model of routes and passes, not a record of any real siren.
What the siren layer shows
The map has two switches in the layers panel, Fire engines and Ambulances. Siren noise is one modeled layer for both, so with either switch on the colors and values include both. The estimate is added by energy to the road noise in every period (Day, Evening, Night) and to the 24 h value.
With a switch on, the map also draws the modeled routes from each station to the scene, the stations, and (for ambulances) the emergency rooms, and replays sample trips as flashing bars of light, sped up. The lights are an illustration and do not change the noise values. Switched off, the map is road traffic, trains and aircraft only.
How the estimate is made
The model takes LAFD’s emergency responses for 2023 to 2025 by district and hour, routes each one from its station over the street network to points spread in proportion to building footprints (ambulances on to the nearest emergency room), and so gets modeled passes per street in each period. Each pass is treated as a moving siren of 120 dB(A) at 3 m on its axis (California Code of Regulations, Title 13, section 1028), lowered by 6 dB for the average over all directions, then carried to each place with spreading, air absorption, ground effect and the shielding of housing.
The place panel also counts the modeled responses whose route passes within about 100 m of a building. Both the colors and that count are for the building you select, not a record of what happened there.
What the siren layer leaves out
- Everything outside the City of Los Angeles. LAPD, the Sheriff, the CHP, LA County Fire and private ambulances are not included, and nothing is added outside the City.
- Real trips. The routes are modeled, not observed. The model assumes every counted vehicle used its siren, so it is an upper estimate, good to about 5 dB.
- Single buildings, terrain and wind. The wall facing away from the street gets the same siren level as the wall facing it.
- The weather views. The Evening and Night weather views show road noise only. See wind and noise.
- Everything else that is not modeled: construction, events, nightlife, neighbors, helicopters, car horns and wildlife, as listed on Limits.
How to use it for a street or an address
Search the address, then switch Fire engines and Ambulances on and off and compare the two values. The place panel also warns when a fire station is close by. Treat the difference as the size of the estimate, not as a prediction for any night. See how to look up an address, and How it’s made and Sources & methods for the method and sources.
Open this on the map
The links open the map at a central point for the sirens layer, which covers the City of Los Angeles only. They are not a list of loud places. Pan the map to any street in the City to see its estimate.
- Downtown Los Angeles with Fire engines and Ambulances on (Night view, sirens in the colors)
- The same place with sirens off (road and train noise only, for comparison)
- The City of Los Angeles with sirens on, wider (24-hour view)
Common questions
Does the Quiet LA map show siren noise?
Only as an optional estimate of LAFD fire engine and ambulance responses in the City of Los Angeles. The Fire engines and Ambulances switches (on by default) turn it on and off. Other sirens, and any siren outside the City, are not modeled.
Are the siren levels measured?
No. They are modeled from LAFD response counts and a standard siren level, and assume every counted vehicle used its siren. They are an upper estimate, good to about 5 dB.
How do I see where fire engines and ambulances go?
With Fire engines or Ambulances on in the layers panel (they are on by default), the map draws modeled routes, the stations and the emergency rooms, and replays sample trips. The routes are modeled, not observed.
Who do I contact about siren or other emergency vehicle noise?
Emergency vehicle sirens are a public safety matter, and the map cannot say whether any rule is met. For other noise contacts, see who to call about noise in Los Angeles.
Sources
- LAFD Response Metrics (City of Los Angeles open data) Emergency responses by district and hour, 2023 to 2025. CC0 1.0. The counts behind the Sirens estimate.
- California Code of Regulations, Title 13, section 1028 Siren performance, Class A: 120 dB(A) at 3 m, the source level used for the estimate.
- OpenStreetMap contributors Street network for the modeled routes and emergency-room locations. Open Database License (ODbL) 1.0.