Monthly Diffusion Tube Readings

The results below show raw data, they are provisional and have not yet been annualised, bias adjusted or distance corrected, the data should be used for indicative purposes only. The adjusted results for this year will be used for the Annual Status Report for Air Quality (ASR) due to be completed in June 2025. The ASR for 2024 based on last year’s diffusion tube readings can be viewed below.

All periods of exposure are across four to five weeks, in accordance with DEFRA recommendations.

Monthly Readings 2025

Site Name	Location	X OS Grid Ref (Easting)	Y OS Grid Ref (Northing)	NO₂ Concentrations μg/m³
				Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct/Nov*	Dec
MV1	West Street, Dorking	516388	149366	22	n/d	13	26	10	11
MV2	Vincent Lane CH, Dorking	516273	148876	22	19	16	21	11	13
MV3	Lonsdale Road, Dorking	516869	149797	N/D	14	9	21	16	14
MV4	A24 Beare Green	517819	143055	23	21	15	25	11	13
MV5	Osbrooks Lodge, A24 Horsham Road, Capel	517227	138685	11	16	6	14	7	8
MV6	Surrey County Council Highways Depot	517210	157200	23	30	n/d	12	n/d	12
MV7	A25 Reigate Road, Betchworth	520204	150578	15	18	11	16	7	8
MV8	8 Russ Hill, Charlwood	523412	140582	16	21	19	15	9	12
MV9	Withey Meadows, Hookwood	526913	142369	11	16	n/d	11	9	13
MV10	Green Lane, Ashstead	517712	156744	21	n/d	n/d	n/d	n/d	n/d
MV11	Green Lane, Ashstead	517804	156751	23	n/d	15	15	9	12
MV12	Green Lane (Quarry Gardens)	517674	156840	19	n/d	18	15	n/d	n/d
MV13	Vincent Lane WS, Dorking	516120	149357	28	20	19	21	10	16
MV14	Pippbrook Council Offices, Dorking	517035	149805	12	22	11	14	11	14
MV15	Square About, Bookham	513483	154600	25	25	26	13	11	13
MV16	Cobham Road, Fetcham	514677	156557	N/D	17	27	15	14	14
MV17	Leret Road, Leatherhead	516763	156563	23	20	27	10	12	9
MV18	Deepdene Roundabout	517241	149847	30	24	29	15	12	15
MV19	Lowfield Heath Road	524909	140231	19	14	22	15	12	13

n/d – no data available