Road & rail noise map for Letchworth
Town in Hertfordshire, Eastern
We analysed 916 postcodes in and around Letchworth, Hertfordshire against DEFRA's Strategic Noise Mapping (Round 4, 2022). 9% of them (84) have mapped road noise of 55 dB or more by day, and 2% have mapped rail noise. 89% of postcodes have no mapped road or rail noise at all — though that reflects major-source modelling, not guaranteed quiet. The highest modelled level we found is at SG6 2EG (road noise 60.0–64.9 dB by day).
Noise map of Letchworth
How many postcodes are affected?
Road noise
| Band | Day (LAeq,16h) | Night (Lnight) |
|---|---|---|
| 55.0–59.9 dB day · 50.0–54.9 dB night | 7% (63) | 2% (20) |
| 60.0–64.9 dB day · 55.0–59.9 dB night | 2% (21) | <1% (8) |
| 65.0–69.9 dB day · 60.0–64.9 dB night | 0% (0) | 0% (0) |
| 70.0–74.9 dB day · 65.0–69.9 dB night | 0% (0) | 0% (0) |
| 75.0 dB or more day · 70.0 dB or more night | 0% (0) | 0% (0) |
| Below mapped bands / not mapped | 91% | 97% |
Rail noise
| Band | Day (LAeq,16h) | Night (Lnight) |
|---|---|---|
| 55.0–59.9 dB day · 50.0–54.9 dB night | 1% (12) | 2% (17) |
| 60.0–64.9 dB day · 55.0–59.9 dB night | <1% (2) | <1% (2) |
| 65.0–69.9 dB day · 60.0–64.9 dB night | 0% (0) | 0% (0) |
| 70.0–74.9 dB day · 65.0–69.9 dB night | 0% (0) | 0% (0) |
| 75.0 dB or more day · 70.0 dB or more night | 0% (0) | 0% (0) |
| Below mapped bands / not mapped | 98% | 98% |
Share of the 916 postcodes within ~5 km of the Letchworth centre. Source: DEFRA Strategic Noise Mapping Round 4 (2022), Open Government Licence.
Noisiest postcodes in and around Letchworth
Check a specific postcode
Example searches: SG6 2DS · SG6 2EE · SG6 1QL · SG5 3RX · SG5 3TZ · SG6 2EG
What this data does — and doesn't — cover
- Modelled, not measured.These are DEFRA's computer-modelled estimates (Round 4, 2022), not microphone readings at your door.
- Major sources only. The model covers major roads, major railways and large urban areas. Smaller local roads, neighbours, pubs, building sites and aircraft are not included.
- No mapped noise ≠ quiet. If a location shows no band, it means it falls outside the mapped contours — not that it is silent.
- 2022 snapshot.New roads, developments or traffic changes since 2022 won't show. The next DEFRA round is due around 2027.
More detail on the methodology page.
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Nearby areas
Frequently asked questions
- How noisy is Letchworth?
- We analysed 916 postcodes in and around Letchworth, Hertfordshire against DEFRA's Strategic Noise Mapping (Round 4, 2022). 9% of them (84) have mapped road noise of 55 dB or more by day, and 2% have mapped rail noise. 89% of postcodes have no mapped road or rail noise at all — though that reflects major-source modelling, not guaranteed quiet. The highest modelled level we found is at SG6 2EG (road noise 60.0–64.9 dB by day).
- Where is the most road noise in Letchworth?
- The postcodes with the highest modelled daytime levels in and around Letchworth are SG6 2EG, SG6 3GY, SG6 3JP, based on DEFRA's 2022 model of major roads and railways.