O3, last 14 days

O₃ concentrations per day (µg/m³), 31/08/2026 - 13/09/2026

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 31/08 01/09 02/09 03/09 04/09 05/09 06/09 07/09 08/09 09/09 10/09 11/09 12/09 13/09

41B011 Sint-Agatha-Berchem 62.5 89 78 60 63.5 77.5 97 107 80 64 81 71.5 75.5 50

41MEU1 Neder-Over-Heembeek 58.5 85.5 75 58.5 48.5 76.5 97.5 101.5 76 63 79 66 72 49.5

41N043 Voorhaven (Haren) 58.5 84.5 70 54 56 73 86.5 97.5 71.5 60.5 74 63 68 47

41R001 Sint-Jans-Molenbeek 58 86 75.5 58 56.5 70 89 87 75.5 57.5 74 64.5 70 46.5

41R012 Ukkel 57 91 72.5 66 59 78.5 86 102.5 81.5 64.5 74.5 67.5 69 50

42N016 Dessel 81 93.5 84 62 72.5 74 97 122 81 61.5 83.5 61 73.5 46

42N027 Bree 69.5 97.5 95 67.5 74 82 99.5 128.5 89.5 66 88.5 70.5 78.5 52.5

42N035 Aarschot 71.5 95 89 69.5 68.5 80 101 126 92 66.5 87.5 78 81.5 57

42N040 Sint-Pieters-Leeuw 64 91 80 60.5 61.5 79.5 98 107.5 83 66.5 80.5 72.5 73 49

42N046 Gellik 68 93 94.5 66 65 81.5 96 123.5 86 67.5 88.5 71 77 59.5

42N047 Hasselt 61.5 92 89.5 61.5 64 78.5 97.5 120 86.5 63.5 83.5 69 74 54

42R801 Borgerhout 79.5 90 80 71 70.5 74.5 88.5 110 79.5 64.5 81.5 60.5 75.5 46.5

42R811 Schoten 81 88.5 83.5 71 66.5 73.5 95.5 114 80.5 62 85 61.5 83 53.5

42R842 Mechelen (Hendrik Speecqvest) 64.5 75 69.5 64.5 58.5 71.5 89 100.5 78.5 57.5 75.5 59 69.5 53

44M705 Roeselare (Haven) 75 97.5 84 75.5 75 83.5 98 79 76.5 79.5 90 75.5 85 57.5

44N012 Moerkerke 81 94 79 72.5 83 76.5 102 78 71 75 92 69.5 79 53

44N029 Houtem (Veurne) 72 89 77 64 73 81 95 73 73.5 77.5 84.5 74.5 74.5 57

44R701 Gent (Baudelopark) 73 94 79.5 69 72.5 75.5 101.5 88 76 73.5 88 66 78 50.5

44R710 Destelbergen 77 99.5 82.5 75.5 76.5 79 99.5 97.5 78 73 91 69 83 52.5

43N060 Havinnes 62.5 84 75 50.5 55.5 78 87.5 82 72 64.5 74.5 66 79 52.5

43N064 Rixensart 69 101.5 87 68 56.5 87 100 108.5 90 71 82.5 76.5 78 56.5

43N066 Eupen 63 82.5 84 76.5 50.5 74 87 108.5 70.5 58.5 79 73 71.5 58.5

43N070 Mons 43.5 69 64 48.5 25.5 64.5 77 80.5 70.5 59.5 61 52.5 56 39

43N073 Vezin 63 88.5 83 64 52.5 77.5 91 109 78 66 78.5 76.5 70 46.5

43N085 Vielsalm 54.5 68.5 74 40 39.5 68 80.5 94 63.5 60.5 74 69.5 61 55.5

43N093 Sinsin 66.5 88.5 84 69.5 57 80.5 97 113 74 68 79 83.5 73 54.5

43N100 Dourbes 76.5 95.5 91 82 56 85 114 120 84 79.5 88 92.5 81 67.5

43N113 Saint-Ode 68 84.5 80 69 58.5 78.5 101 114.5 75 70.5 81 82 73.5 66

43N121 Offagne 67 85.5 82 67.5 55.5 76.5 105.5 124 78.5 72.5 80 80.5 73 60.5

43N132 Habay-La-Neuve 66 81.5 83.5 71 63.5 74.5 106.5 120.5 70 71 79 80.5 71 52

43R221 Herstal 64.5 78 90.5 58 54 79 90.5 113 76.5 65 79.5 72.5 73.5 54

43R222 Liège (ISSeP) 66.5 91.5 92 72 60 82 90.5 113 76.5 67 79.5 75 76 58

43R240 Engis 59 85.5 85 59 43 74.5 83.5 108 66 62.5 73.5 68 65 30.5

43R401 Namur 65 92.5 85.5 65.5 56 82 93.5 111.5 82.5 67.5 76.5 77.5 72.5 59.5

45R502 Lodelinsart 58 81.5 76.5 63.5 34.5 74 106 99 81.5 63 71.5 71 66 42.5

Interpolated spatial average in :

Brussels 59 89 76 61 57 76 92 104 79 63 77 69 72 50

Flanders 72 92 82 67 67 78 96 101 79 68 86 69 77 53

Wallonia 62 83 80 66 48 75 93 104 75 67 78 75 70 52

Belgium 67 87 81 66 57 76 94 103 77 68 81 72 73 52

% 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	31/08	01/09	02/09	03/09	04/09	05/09	06/09	07/09	08/09	09/09	10/09	11/09	12/09	13/09
41B011	Sint-Agatha-Berchem	62.5	89	78	60	63.5	77.5	97	107	80	64	81	71.5	75.5	50
41MEU1	Neder-Over-Heembeek	58.5	85.5	75	58.5	48.5	76.5	97.5	101.5	76	63	79	66	72	49.5
41N043	Voorhaven (Haren)	58.5	84.5	70	54	56	73	86.5	97.5	71.5	60.5	74	63	68	47
41R001	Sint-Jans-Molenbeek	58	86	75.5	58	56.5	70	89	87	75.5	57.5	74	64.5	70	46.5
41R012	Ukkel	57	91	72.5	66	59	78.5	86	102.5	81.5	64.5	74.5	67.5	69	50
42N016	Dessel	81	93.5	84	62	72.5	74	97	122	81	61.5	83.5	61	73.5	46
42N027	Bree	69.5	97.5	95	67.5	74	82	99.5	128.5	89.5	66	88.5	70.5	78.5	52.5
42N035	Aarschot	71.5	95	89	69.5	68.5	80	101	126	92	66.5	87.5	78	81.5	57
42N040	Sint-Pieters-Leeuw	64	91	80	60.5	61.5	79.5	98	107.5	83	66.5	80.5	72.5	73	49
42N046	Gellik	68	93	94.5	66	65	81.5	96	123.5	86	67.5	88.5	71	77	59.5
42N047	Hasselt	61.5	92	89.5	61.5	64	78.5	97.5	120	86.5	63.5	83.5	69	74	54
42R801	Borgerhout	79.5	90	80	71	70.5	74.5	88.5	110	79.5	64.5	81.5	60.5	75.5	46.5
42R811	Schoten	81	88.5	83.5	71	66.5	73.5	95.5	114	80.5	62	85	61.5	83	53.5
42R842	Mechelen (Hendrik Speecqvest)	64.5	75	69.5	64.5	58.5	71.5	89	100.5	78.5	57.5	75.5	59	69.5	53
44M705	Roeselare (Haven)	75	97.5	84	75.5	75	83.5	98	79	76.5	79.5	90	75.5	85	57.5
44N012	Moerkerke	81	94	79	72.5	83	76.5	102	78	71	75	92	69.5	79	53
44N029	Houtem (Veurne)	72	89	77	64	73	81	95	73	73.5	77.5	84.5	74.5	74.5	57
44R701	Gent (Baudelopark)	73	94	79.5	69	72.5	75.5	101.5	88	76	73.5	88	66	78	50.5
44R710	Destelbergen	77	99.5	82.5	75.5	76.5	79	99.5	97.5	78	73	91	69	83	52.5
43N060	Havinnes	62.5	84	75	50.5	55.5	78	87.5	82	72	64.5	74.5	66	79	52.5
43N064	Rixensart	69	101.5	87	68	56.5	87	100	108.5	90	71	82.5	76.5	78	56.5
43N066	Eupen	63	82.5	84	76.5	50.5	74	87	108.5	70.5	58.5	79	73	71.5	58.5
43N070	Mons	43.5	69	64	48.5	25.5	64.5	77	80.5	70.5	59.5	61	52.5	56	39
43N073	Vezin	63	88.5	83	64	52.5	77.5	91	109	78	66	78.5	76.5	70	46.5
43N085	Vielsalm	54.5	68.5	74	40	39.5	68	80.5	94	63.5	60.5	74	69.5	61	55.5
43N093	Sinsin	66.5	88.5	84	69.5	57	80.5	97	113	74	68	79	83.5	73	54.5
43N100	Dourbes	76.5	95.5	91	82	56	85	114	120	84	79.5	88	92.5	81	67.5
43N113	Saint-Ode	68	84.5	80	69	58.5	78.5	101	114.5	75	70.5	81	82	73.5	66
43N121	Offagne	67	85.5	82	67.5	55.5	76.5	105.5	124	78.5	72.5	80	80.5	73	60.5
43N132	Habay-La-Neuve	66	81.5	83.5	71	63.5	74.5	106.5	120.5	70	71	79	80.5	71	52
43R221	Herstal	64.5	78	90.5	58	54	79	90.5	113	76.5	65	79.5	72.5	73.5	54
43R222	Liège (ISSeP)	66.5	91.5	92	72	60	82	90.5	113	76.5	67	79.5	75	76	58
43R240	Engis	59	85.5	85	59	43	74.5	83.5	108	66	62.5	73.5	68	65	30.5
43R401	Namur	65	92.5	85.5	65.5	56	82	93.5	111.5	82.5	67.5	76.5	77.5	72.5	59.5
45R502	Lodelinsart	58	81.5	76.5	63.5	34.5	74	106	99	81.5	63	71.5	71	66	42.5

Interpolated spatial average in :
Brussels	59	89	76	61	57	76	92	104	79	63	77	69	72	50
Flanders	72	92	82	67	67	78	96	101	79	68	86	69	77	53
Wallonia	62	83	80	66	48	75	93	104	75	67	78	75	70	52
Belgium	67	87	81	66	57	76	94	103	77	68	81	72	73	52

% 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