O3, last 14 days

O₃ concentrations per day (µg/m³), 12/10/2026 - 25/10/2026

Highest hourly meanHighest 8-hourly mean

- Click on the figures in the table cells to get an evolution graph of daily concentrations
- Click on the date to get an interpolation map
- "NA" means no or not enough data were available

Code city 12/10 13/10 14/10 15/10 16/10 17/10 18/10 19/10 20/10 21/10 22/10 23/10 24/10 25/10

41B011 Sint-Agatha-Berchem 66 59.5 69 59.5 64.5 67 46 30 42.5 72 70 64 63.5 91

41MEU1 Neder-Over-Heembeek 66 56.5 62 59.5 65 71 46 33.5 30 60 63.5 59.5 62 77

41N043 Voorhaven (Haren) 55.5 57 59.5 50 62.5 61 43.5 26.5 36 62.5 60.5 60 59 86

41R001 Sint-Jans-Molenbeek 59 58 60.5 51.5 59 61.5 39 29.5 41 64.5 61 58.5 62.5 84

41R012 Ukkel 65 61 58.5 61 66.5 71.5 49 31 39.5 73 66 64 65.5 90.5

42N016 Dessel 19 NA NA NA 77.5 74 54.5 43 43.5 65.5 60 65.5 64 91.5

42N027 Bree 19.5 NA NA NA NA NA NA NA 25 76.5 68.5 69.5 68 96.5

42N035 Aarschot 43 NA NA NA NA 75.5 50.5 43 38 76 71.5 68 64.5 91.5

42N040 Sint-Pieters-Leeuw 65 58.5 67.5 59.5 62 67 47.5 16 NA NA NA 63.5 63.5 90

42N046 Gellik 15 NA NA NA 78.5 74.5 36.5 43.5 31.5 74.5 64.5 70 69.5 92.5

42N047 Hasselt 3.5 NA NA NA 77 74.5 29.5 NA 33 76 64 67.5 68 97.5

42R801 Borgerhout 58 57.5 66 51.5 64.5 72 55 17.5 NA NA NA 57.5 62.5 84.5

42R811 Schoten 69 56.5 71 53.5 71.5 70.5 45.5 15.5 NA NA NA NA NA 72.5

42R842 Mechelen (Hendrik Speecqvest) 65.5 57 62.5 53.5 67 68 43 14 NA NA NA 61.5 64 88.5

44M705 Roeselare (Haven) 67 64 80 47.5 73 69 45 20.5 NA NA NA 68.5 70 95

44N012 Moerkerke 75 75.5 77.5 47.5 76 74.5 57.5 29.5 57 83 72 71 76 90

44N029 Houtem (Veurne) 71.5 66.5 79.5 55 77 77.5 70 39 62 87 77.5 73.5 75.5 92

44R701 Gent (Baudelopark) 67.5 63 68.5 51.5 74 67.5 46 25.5 50.5 79 70 69.5 71 92.5

44R710 Destelbergen 70 64.5 71.5 58 67.5 68.5 46.5 28.5 51.5 82.5 73.5 67.5 69.5 89.5

43N060 Havinnes 63.5 66.5 61.5 50 65.5 67.5 54.5 33 39 78 79.5 70.5 71.5 86.5

43N064 Rixensart 72.5 66 74 62.5 68.5 73.5 50 35.5 32 76 67.5 68 66.5 93.5

43N066 Eupen 65.5 65.5 68.5 69.5 67.5 58.5 28.5 36.5 40.5 65.5 62 56.5 58 75.5

43N070 Mons 50 32.5 46 33 52 63.5 46 29 38.5 57 53 53 54.5 64

43N073 Vezin 67 63.5 61.5 67 59.5 67.5 41.5 24.5 33.5 76 60 62 61.5 84

43N085 Vielsalm 54.5 46.5 59.5 55 58 56 44 33.5 33 50.5 44 39.5 NA NA

43N093 Sinsin 65.5 59.5 67 72.5 66.5 67 56 33.5 43.5 68 57.5 66 65 86.5

43N100 Dourbes 79 69 78 79 70.5 78 59.5 43.5 55 76.5 68 75.5 71.5 93.5

43N113 Saint-Ode 71.5 59 70 70.5 71 68 51.5 44.5 42 66.5 57 73 70.5 91.5

43N121 Offagne 69 56 65.5 66 66.5 66 47.5 46 36.5 63 53 67 63 83

43N132 Habay-La-Neuve 68 45 66.5 62 60 65 54 37 28.5 58 47 62 58.5 79.5

43R221 Herstal 67 61.5 70 67 64.5 66.5 33.5 32.5 22 70 61 66 64.5 86.5

43R222 Liège (ISSeP) 54.5 52.5 55.5 56 51 57.5 31 32 24.5 58.5 53.5 57.5 56.5 64.5

43R240 Engis 62.5 48.5 55.5 59 46 58.5 17 16 19 55.5 48.5 52 48.5 61.5

43R401 Namur 64.5 58 67 65.5 64.5 67.5 40 19 34.5 78.5 64.5 68.5 67 90

45R502 Lodelinsart 66.5 58 55 59.5 63 71 52.5 26 33 42.5 55.5 59 61.5 81.5

Interpolated spatial average in :

Brussels 64 57 63 57 64 67 44 32 38 68 65 62 63 87

Flanders 68 61 71 57 70 71 48 34 43 73 69 67 68 89

Wallonia 65 55 63 62 61 66 46 33 37 65 58 64 64 80

Belgium 67 58 66 59 65 68 47 33 39 69 63 65 66 84

% of the population exposed to O₃ concentrations > 180 μg/m³ in:

Brussels 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Flanders 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Wallonia 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Belgium 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

% of the population exposed to O₃ concentrations > 240 μg/m³ in:

Brussels 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Flanders 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Wallonia 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Belgium 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Code	city	12/10	13/10	14/10	15/10	16/10	17/10	18/10	19/10	20/10	21/10	22/10	23/10	24/10	25/10
41B011	Sint-Agatha-Berchem	66	59.5	69	59.5	64.5	67	46	30	42.5	72	70	64	63.5	91
41MEU1	Neder-Over-Heembeek	66	56.5	62	59.5	65	71	46	33.5	30	60	63.5	59.5	62	77
41N043	Voorhaven (Haren)	55.5	57	59.5	50	62.5	61	43.5	26.5	36	62.5	60.5	60	59	86
41R001	Sint-Jans-Molenbeek	59	58	60.5	51.5	59	61.5	39	29.5	41	64.5	61	58.5	62.5	84
41R012	Ukkel	65	61	58.5	61	66.5	71.5	49	31	39.5	73	66	64	65.5	90.5
42N016	Dessel	19	NA	NA	NA	77.5	74	54.5	43	43.5	65.5	60	65.5	64	91.5
42N027	Bree	19.5	NA	NA	NA	NA	NA	NA	NA	25	76.5	68.5	69.5	68	96.5
42N035	Aarschot	43	NA	NA	NA	NA	75.5	50.5	43	38	76	71.5	68	64.5	91.5
42N040	Sint-Pieters-Leeuw	65	58.5	67.5	59.5	62	67	47.5	16	NA	NA	NA	63.5	63.5	90
42N046	Gellik	15	NA	NA	NA	78.5	74.5	36.5	43.5	31.5	74.5	64.5	70	69.5	92.5
42N047	Hasselt	3.5	NA	NA	NA	77	74.5	29.5	NA	33	76	64	67.5	68	97.5
42R801	Borgerhout	58	57.5	66	51.5	64.5	72	55	17.5	NA	NA	NA	57.5	62.5	84.5
42R811	Schoten	69	56.5	71	53.5	71.5	70.5	45.5	15.5	NA	NA	NA	NA	NA	72.5
42R842	Mechelen (Hendrik Speecqvest)	65.5	57	62.5	53.5	67	68	43	14	NA	NA	NA	61.5	64	88.5
44M705	Roeselare (Haven)	67	64	80	47.5	73	69	45	20.5	NA	NA	NA	68.5	70	95
44N012	Moerkerke	75	75.5	77.5	47.5	76	74.5	57.5	29.5	57	83	72	71	76	90
44N029	Houtem (Veurne)	71.5	66.5	79.5	55	77	77.5	70	39	62	87	77.5	73.5	75.5	92
44R701	Gent (Baudelopark)	67.5	63	68.5	51.5	74	67.5	46	25.5	50.5	79	70	69.5	71	92.5
44R710	Destelbergen	70	64.5	71.5	58	67.5	68.5	46.5	28.5	51.5	82.5	73.5	67.5	69.5	89.5
43N060	Havinnes	63.5	66.5	61.5	50	65.5	67.5	54.5	33	39	78	79.5	70.5	71.5	86.5
43N064	Rixensart	72.5	66	74	62.5	68.5	73.5	50	35.5	32	76	67.5	68	66.5	93.5
43N066	Eupen	65.5	65.5	68.5	69.5	67.5	58.5	28.5	36.5	40.5	65.5	62	56.5	58	75.5
43N070	Mons	50	32.5	46	33	52	63.5	46	29	38.5	57	53	53	54.5	64
43N073	Vezin	67	63.5	61.5	67	59.5	67.5	41.5	24.5	33.5	76	60	62	61.5	84
43N085	Vielsalm	54.5	46.5	59.5	55	58	56	44	33.5	33	50.5	44	39.5	NA	NA
43N093	Sinsin	65.5	59.5	67	72.5	66.5	67	56	33.5	43.5	68	57.5	66	65	86.5
43N100	Dourbes	79	69	78	79	70.5	78	59.5	43.5	55	76.5	68	75.5	71.5	93.5
43N113	Saint-Ode	71.5	59	70	70.5	71	68	51.5	44.5	42	66.5	57	73	70.5	91.5
43N121	Offagne	69	56	65.5	66	66.5	66	47.5	46	36.5	63	53	67	63	83
43N132	Habay-La-Neuve	68	45	66.5	62	60	65	54	37	28.5	58	47	62	58.5	79.5
43R221	Herstal	67	61.5	70	67	64.5	66.5	33.5	32.5	22	70	61	66	64.5	86.5
43R222	Liège (ISSeP)	54.5	52.5	55.5	56	51	57.5	31	32	24.5	58.5	53.5	57.5	56.5	64.5
43R240	Engis	62.5	48.5	55.5	59	46	58.5	17	16	19	55.5	48.5	52	48.5	61.5
43R401	Namur	64.5	58	67	65.5	64.5	67.5	40	19	34.5	78.5	64.5	68.5	67	90
45R502	Lodelinsart	66.5	58	55	59.5	63	71	52.5	26	33	42.5	55.5	59	61.5	81.5

Interpolated spatial average in :
Brussels	64	57	63	57	64	67	44	32	38	68	65	62	63	87
Flanders	68	61	71	57	70	71	48	34	43	73	69	67	68	89
Wallonia	65	55	63	62	61	66	46	33	37	65	58	64	64	80
Belgium	67	58	66	59	65	68	47	33	39	69	63	65	66	84

% of the population exposed to O₃ concentrations > 180 μg/m³ in:
Brussels	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Flanders	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Wallonia	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Belgium	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%

% of the population exposed to O₃ concentrations > 240 μg/m³ in:
Brussels	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Flanders	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Wallonia	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Belgium	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%

Color legend: Kleurlegende

These data are not validated : they should not be used for any study whatsoever
The use or publication of the data is allowed only when the source (www.irceline.be) is acknowledged