O3, last 14 days

O₃ concentrations per day (µg/m³), 28/09/2026 - 11/10/2026

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 28/09 29/09 30/09 01/10 02/10 03/10 04/10 05/10 06/10 07/10 08/10 09/10 10/10 11/10

41B011 Sint-Agatha-Berchem 53 98.5 75.5 70.5 74 89.5 101.5 88.5 81 97.5 64.5 52 66 69

41MEU1 Neder-Over-Heembeek 57 101.5 70 69 72.5 97 103.5 84 77 91.5 68.5 43.5 58 71

41N043 Voorhaven (Haren) 49 81.5 63.5 61.5 58 80 86.5 76 64 82.5 61 44 59 64

41R001 Sint-Jans-Molenbeek 49 91 77 63 63.5 82.5 91.5 77.5 65.5 85 59.5 45 57.5 60

41R012 Ukkel 58 95 73.5 74.5 67 92.5 101.5 87.5 86.5 82.5 67.5 52 62.5 67.5

42N016 Dessel 57 119 81.5 69.5 81 93 104 93 92 117.5 68.5 68.5 63 71.5

42N027 Bree 76.5 122.5 100 69 82.5 95.5 108.5 105 108 102.5 72 64.5 64.5 71

42N035 Aarschot 73 116 94.5 80 85 99.5 112 101.5 102 108.5 76 62.5 66.5 74

42N040 Sint-Pieters-Leeuw 52.5 99.5 75.5 77.5 78.5 100.5 104 93.5 87.5 103 64.5 51.5 62.5 67

42N046 Gellik 82.5 112.5 98.5 73 80 98.5 105 109 98 105 70.5 59 68.5 68

42N047 Hasselt 68.5 115 93.5 70.5 78 93.5 104 101 96 96.5 67.5 54.5 62 66

42R801 Borgerhout 53.5 98 67.5 77 76.5 81 103.5 68 66.5 93.5 72.5 65 62 74

42R811 Schoten 51 116 76.5 70.5 79.5 92 105 70.5 70 90 71.5 69.5 60.5 73.5

42R842 Mechelen (Hendrik Speecqvest) 52 96.5 71.5 63.5 69.5 83 96 75 56 98.5 68 59.5 57.5 62

44M705 Roeselare (Haven) 70 93 59.5 79 86.5 82.5 103 5 NA NA NA 62.5 67 70

44N012 Moerkerke 66.5 101.5 62 79.5 78.5 85.5 90.5 43.5 NA NA NA 73 71.5 77

44N029 Houtem (Veurne) 70 94.5 69.5 80 79.5 81.5 84.5 27.5 NA NA NA 64 68 68.5

44R701 Gent (Baudelopark) 62.5 108.5 73 74 81.5 84.5 106.5 62 NA NA NA 63.5 64 71.5

44R710 Destelbergen 59.5 111.5 71.5 77.5 80 84.5 108.5 11.5 NA NA NA NA NA NA

43N060 Havinnes 46.5 95 71 78.5 72 78.5 101 89 60 60.5 60 65 70 62.5

43N064 Rixensart 70.5 105 85 82.5 81.5 95 106.5 102 99 95 69 54.5 68 70

43N066 Eupen 102.5 102.5 100 68.5 78 88 92.5 106 91.5 99 68 49.5 58 56.5

43N070 Mons 53.5 80.5 64.5 57 69 89.5 93.5 89.5 83 80 63.5 38.5 43 42

43N073 Vezin 79 103 89.5 71 77.5 91.5 92.5 98 92 104 60.5 51 60.5 57

43N085 Vielsalm 85 96 91 42 27.5 66.5 77.5 79.5 84.5 90.5 59.5 41 44.5 46

43N093 Sinsin 95.5 108 95.5 75 84 95 89.5 103.5 92.5 102.5 77 50 65.5 66.5

43N100 Dourbes 97 106.5 98.5 89 89.5 100 97 117.5 110 108.5 75.5 62 70 66.5

43N113 Saint-Ode 98 108.5 96 65 85 87 89.5 96.5 103 99 80.5 55 63 64

43N121 Offagne 101.5 101.5 92.5 69 86.5 88 89 95.5 104 92.5 73 48 62.5 60.5

43N132 Habay-La-Neuve 110 97.5 89 48 82.5 84 83 95.5 107.5 88 69.5 46 57 53.5

43R221 Herstal 89.5 103 86.5 68 69 89.5 91.5 108 88.5 95 74 44.5 65 60

43R222 Liège (ISSeP) 74.5 81 72.5 51.5 54.5 71 72.5 80 73 72 55.5 42 50.5 46.5

43R240 Engis 72.5 104.5 85.5 57.5 66 79 85 92.5 76.5 91.5 57 33 50.5 43.5

43R401 Namur 75 100 88 74 71.5 88.5 91 93.5 86.5 97 66.5 54.5 65 65

45R502 Lodelinsart 65 95.5 78 65 67.5 90.5 95.5 91.5 84.5 98 67 44.5 53 58.5

Interpolated spatial average in :

Brussels 55 95 72 71 71 88 97 85 78 87 65 49 62 66

Flanders 61 105 75 74 79 88 100 86 76 88 68 59 65 70

Wallonia 82 98 86 64 71 86 89 95 90 91 65 49 59 57

Belgium 72 101 81 68 75 87 94 91 84 90 67 53 61 63

% 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	28/09	29/09	30/09	01/10	02/10	03/10	04/10	05/10	06/10	07/10	08/10	09/10	10/10	11/10
41B011	Sint-Agatha-Berchem	53	98.5	75.5	70.5	74	89.5	101.5	88.5	81	97.5	64.5	52	66	69
41MEU1	Neder-Over-Heembeek	57	101.5	70	69	72.5	97	103.5	84	77	91.5	68.5	43.5	58	71
41N043	Voorhaven (Haren)	49	81.5	63.5	61.5	58	80	86.5	76	64	82.5	61	44	59	64
41R001	Sint-Jans-Molenbeek	49	91	77	63	63.5	82.5	91.5	77.5	65.5	85	59.5	45	57.5	60
41R012	Ukkel	58	95	73.5	74.5	67	92.5	101.5	87.5	86.5	82.5	67.5	52	62.5	67.5
42N016	Dessel	57	119	81.5	69.5	81	93	104	93	92	117.5	68.5	68.5	63	71.5
42N027	Bree	76.5	122.5	100	69	82.5	95.5	108.5	105	108	102.5	72	64.5	64.5	71
42N035	Aarschot	73	116	94.5	80	85	99.5	112	101.5	102	108.5	76	62.5	66.5	74
42N040	Sint-Pieters-Leeuw	52.5	99.5	75.5	77.5	78.5	100.5	104	93.5	87.5	103	64.5	51.5	62.5	67
42N046	Gellik	82.5	112.5	98.5	73	80	98.5	105	109	98	105	70.5	59	68.5	68
42N047	Hasselt	68.5	115	93.5	70.5	78	93.5	104	101	96	96.5	67.5	54.5	62	66
42R801	Borgerhout	53.5	98	67.5	77	76.5	81	103.5	68	66.5	93.5	72.5	65	62	74
42R811	Schoten	51	116	76.5	70.5	79.5	92	105	70.5	70	90	71.5	69.5	60.5	73.5
42R842	Mechelen (Hendrik Speecqvest)	52	96.5	71.5	63.5	69.5	83	96	75	56	98.5	68	59.5	57.5	62
44M705	Roeselare (Haven)	70	93	59.5	79	86.5	82.5	103	5	NA	NA	NA	62.5	67	70
44N012	Moerkerke	66.5	101.5	62	79.5	78.5	85.5	90.5	43.5	NA	NA	NA	73	71.5	77
44N029	Houtem (Veurne)	70	94.5	69.5	80	79.5	81.5	84.5	27.5	NA	NA	NA	64	68	68.5
44R701	Gent (Baudelopark)	62.5	108.5	73	74	81.5	84.5	106.5	62	NA	NA	NA	63.5	64	71.5
44R710	Destelbergen	59.5	111.5	71.5	77.5	80	84.5	108.5	11.5	NA	NA	NA	NA	NA	NA
43N060	Havinnes	46.5	95	71	78.5	72	78.5	101	89	60	60.5	60	65	70	62.5
43N064	Rixensart	70.5	105	85	82.5	81.5	95	106.5	102	99	95	69	54.5	68	70
43N066	Eupen	102.5	102.5	100	68.5	78	88	92.5	106	91.5	99	68	49.5	58	56.5
43N070	Mons	53.5	80.5	64.5	57	69	89.5	93.5	89.5	83	80	63.5	38.5	43	42
43N073	Vezin	79	103	89.5	71	77.5	91.5	92.5	98	92	104	60.5	51	60.5	57
43N085	Vielsalm	85	96	91	42	27.5	66.5	77.5	79.5	84.5	90.5	59.5	41	44.5	46
43N093	Sinsin	95.5	108	95.5	75	84	95	89.5	103.5	92.5	102.5	77	50	65.5	66.5
43N100	Dourbes	97	106.5	98.5	89	89.5	100	97	117.5	110	108.5	75.5	62	70	66.5
43N113	Saint-Ode	98	108.5	96	65	85	87	89.5	96.5	103	99	80.5	55	63	64
43N121	Offagne	101.5	101.5	92.5	69	86.5	88	89	95.5	104	92.5	73	48	62.5	60.5
43N132	Habay-La-Neuve	110	97.5	89	48	82.5	84	83	95.5	107.5	88	69.5	46	57	53.5
43R221	Herstal	89.5	103	86.5	68	69	89.5	91.5	108	88.5	95	74	44.5	65	60
43R222	Liège (ISSeP)	74.5	81	72.5	51.5	54.5	71	72.5	80	73	72	55.5	42	50.5	46.5
43R240	Engis	72.5	104.5	85.5	57.5	66	79	85	92.5	76.5	91.5	57	33	50.5	43.5
43R401	Namur	75	100	88	74	71.5	88.5	91	93.5	86.5	97	66.5	54.5	65	65
45R502	Lodelinsart	65	95.5	78	65	67.5	90.5	95.5	91.5	84.5	98	67	44.5	53	58.5

Interpolated spatial average in :
Brussels	55	95	72	71	71	88	97	85	78	87	65	49	62	66
Flanders	61	105	75	74	79	88	100	86	76	88	68	59	65	70
Wallonia	82	98	86	64	71	86	89	95	90	91	65	49	59	57
Belgium	72	101	81	68	75	87	94	91	84	90	67	53	61	63

% 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