O3, last 14 days

O₃ concentrations per day (µg/m³), 02/03/2026 - 15/03/2026

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 02/03 03/03 04/03 05/03 06/03 07/03 08/03 09/03 10/03 11/03 12/03 13/03 14/03 15/03

41B011 Sint-Agatha-Berchem 80 82.5 84 84 70.5 20 38 85.5 67.5 69 78.5 82 78.5 82.5

41MEU1 Neder-Over-Heembeek 81.5 79 74 79 76 39 43.5 4 NA NA NA 73.5 70.5 78

41N043 Voorhaven (Haren) 66.5 71 67 68 66.5 36 39 1.5 NA NA NA 68.5 67 73.5

41R001 Sint-Jans-Molenbeek 70.5 59.5 64.5 70.5 57.5 15 26 1 NA NA NA 65.5 65 71

41R012 Ukkel 80.5 74 74 82.5 72.5 29.5 48.5 37 NA NA NA 79 75.5 78.5

42N016 Dessel 74 78.5 74 74.5 67.5 46.5 52.5 7 NA NA NA 86.5 73 80.5

42N027 Bree 85.5 90 80.5 75.5 69 63 69 8.5 NA NA NA 86.5 76.5 82.5

42N035 Aarschot 80.5 82 84.5 83 73 45 73 86.5 74 65.5 77 77.5 80 81

42N040 Sint-Pieters-Leeuw 78.5 81.5 83 84 61.5 20.5 52.5 81.5 71 69.5 73 80.5 80.5 77

42N046 Gellik 81.5 87.5 77 80 57.5 49.5 73 19 NA NA NA 88 70.5 NA

42N047 Hasselt 84 86.5 89.5 87 66.5 56.5 88.5 2 NA NA NA 83.5 79.5 78.5

42R801 Borgerhout 70 61 67 70 43.5 37.5 51 3.5 NA NA NA NA NA 78.5

42R811 Schoten 84 67 85 84.5 55.5 36 57 83.5 61.5 68 76.5 84 70.5 78.5

42R842 Mechelen (Hendrik Speecqvest) 80 68 67 79 47 31.5 38 70.5 62.5 58.5 76 70 77.5 79.5

44M705 Roeselare (Haven) 58 NA NA NA 59.5 44.5 40.5 79.5 65.5 75 82.5 82.5 82 87

44N012 Moerkerke 54 NA NA NA NA NA 32.5 73 67.5 74.5 83 83.5 71 88

44N029 Houtem (Veurne) 53.5 NA NA NA 54 58 36 73.5 65.5 78 83.5 85.5 80.5 85

44R701 Gent (Baudelopark) 58.5 NA NA NA 6 16 45 79.5 62 71 79.5 80 75.5 84

44R710 Destelbergen 63.5 NA NA NA 72.5 27.5 44.5 82 64.5 71 80 84.5 71.5 85.5

43N060 Havinnes 70.5 66.5 82 75 40 13 39 67.5 59 65 65.5 73.5 68 74.5

43N064 Rixensart 86 92 93 90 73.5 37 70 90 72 73.5 81 82 78.5 85

43N066 Eupen 70 NA NA NA 56 72 81.5 85 70.5 70 75 73.5 61 73

43N070 Mons 65.5 90 89 74 47 22 72.5 69.5 58.5 56.5 69.5 65.5 69.5 73.5

43N073 Vezin 83.5 88 90 86.5 78.5 55 76 85.5 78.5 70.5 75.5 82 73 78

43N085 Vielsalm 54 NA NA NA 58 86.5 93.5 79 67 64 71 74 66 62.5

43N093 Sinsin 83.5 87 89.5 86 72 74.5 95.5 84.5 78 78 77 83.5 76.5 76

43N100 Dourbes 88 99 99 98 90 86 102 96.5 87.5 81 80.5 93.5 83 85

43N113 Saint-Ode 75 88 92.5 84 67 85 99.5 88.5 89 77 78 87 79 78

43N121 Offagne 74 69.5 77.5 74.5 44 66.5 73.5 71.5 56.5 55.5 69 63.5 54 61.5

43N132 Habay-La-Neuve 75.5 83 81 76.5 57 85 88.5 82 64.5 68 72 80.5 75.5 72.5

43R221 Herstal 29.5 NA NA NA 51 61 86 83 70 72 76.5 78 67.5 78

43R222 Liège (ISSeP) 60 NA NA NA 69.5 63.5 88.5 84.5 78.5 77.5 80.5 77 70.5 80.5

43R240 Engis 63 NA NA NA 73.5 61.5 73 86.5 73.5 73 77 76.5 59.5 74

43R401 Namur 81 84.5 84 84.5 72.5 43 82.5 81.5 79.5 71.5 77.5 79.5 74 78

45R502 Lodelinsart 74 80.5 85.5 81.5 64.5 31 91 79 67.5 57.5 73 65.5 70 70

Interpolated spatial average in :

Brussels 76 71 71 77 66 23 40 83 67 63 76 74 72 76

Flanders 81 77 81 80 65 41 51 85 69 73 85 83 73 84

Wallonia 79 84 86 83 65 59 79 83 69 70 76 79 72 75

Belgium 80 81 84 81 65 51 66 84 69 71 80 80 73 79

% 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	02/03	03/03	04/03	05/03	06/03	07/03	08/03	09/03	10/03	11/03	12/03	13/03	14/03	15/03
41B011	Sint-Agatha-Berchem	80	82.5	84	84	70.5	20	38	85.5	67.5	69	78.5	82	78.5	82.5
41MEU1	Neder-Over-Heembeek	81.5	79	74	79	76	39	43.5	4	NA	NA	NA	73.5	70.5	78
41N043	Voorhaven (Haren)	66.5	71	67	68	66.5	36	39	1.5	NA	NA	NA	68.5	67	73.5
41R001	Sint-Jans-Molenbeek	70.5	59.5	64.5	70.5	57.5	15	26	1	NA	NA	NA	65.5	65	71
41R012	Ukkel	80.5	74	74	82.5	72.5	29.5	48.5	37	NA	NA	NA	79	75.5	78.5
42N016	Dessel	74	78.5	74	74.5	67.5	46.5	52.5	7	NA	NA	NA	86.5	73	80.5
42N027	Bree	85.5	90	80.5	75.5	69	63	69	8.5	NA	NA	NA	86.5	76.5	82.5
42N035	Aarschot	80.5	82	84.5	83	73	45	73	86.5	74	65.5	77	77.5	80	81
42N040	Sint-Pieters-Leeuw	78.5	81.5	83	84	61.5	20.5	52.5	81.5	71	69.5	73	80.5	80.5	77
42N046	Gellik	81.5	87.5	77	80	57.5	49.5	73	19	NA	NA	NA	88	70.5	NA
42N047	Hasselt	84	86.5	89.5	87	66.5	56.5	88.5	2	NA	NA	NA	83.5	79.5	78.5
42R801	Borgerhout	70	61	67	70	43.5	37.5	51	3.5	NA	NA	NA	NA	NA	78.5
42R811	Schoten	84	67	85	84.5	55.5	36	57	83.5	61.5	68	76.5	84	70.5	78.5
42R842	Mechelen (Hendrik Speecqvest)	80	68	67	79	47	31.5	38	70.5	62.5	58.5	76	70	77.5	79.5
44M705	Roeselare (Haven)	58	NA	NA	NA	59.5	44.5	40.5	79.5	65.5	75	82.5	82.5	82	87
44N012	Moerkerke	54	NA	NA	NA	NA	NA	32.5	73	67.5	74.5	83	83.5	71	88
44N029	Houtem (Veurne)	53.5	NA	NA	NA	54	58	36	73.5	65.5	78	83.5	85.5	80.5	85
44R701	Gent (Baudelopark)	58.5	NA	NA	NA	6	16	45	79.5	62	71	79.5	80	75.5	84
44R710	Destelbergen	63.5	NA	NA	NA	72.5	27.5	44.5	82	64.5	71	80	84.5	71.5	85.5
43N060	Havinnes	70.5	66.5	82	75	40	13	39	67.5	59	65	65.5	73.5	68	74.5
43N064	Rixensart	86	92	93	90	73.5	37	70	90	72	73.5	81	82	78.5	85
43N066	Eupen	70	NA	NA	NA	56	72	81.5	85	70.5	70	75	73.5	61	73
43N070	Mons	65.5	90	89	74	47	22	72.5	69.5	58.5	56.5	69.5	65.5	69.5	73.5
43N073	Vezin	83.5	88	90	86.5	78.5	55	76	85.5	78.5	70.5	75.5	82	73	78
43N085	Vielsalm	54	NA	NA	NA	58	86.5	93.5	79	67	64	71	74	66	62.5
43N093	Sinsin	83.5	87	89.5	86	72	74.5	95.5	84.5	78	78	77	83.5	76.5	76
43N100	Dourbes	88	99	99	98	90	86	102	96.5	87.5	81	80.5	93.5	83	85
43N113	Saint-Ode	75	88	92.5	84	67	85	99.5	88.5	89	77	78	87	79	78
43N121	Offagne	74	69.5	77.5	74.5	44	66.5	73.5	71.5	56.5	55.5	69	63.5	54	61.5
43N132	Habay-La-Neuve	75.5	83	81	76.5	57	85	88.5	82	64.5	68	72	80.5	75.5	72.5
43R221	Herstal	29.5	NA	NA	NA	51	61	86	83	70	72	76.5	78	67.5	78
43R222	Liège (ISSeP)	60	NA	NA	NA	69.5	63.5	88.5	84.5	78.5	77.5	80.5	77	70.5	80.5
43R240	Engis	63	NA	NA	NA	73.5	61.5	73	86.5	73.5	73	77	76.5	59.5	74
43R401	Namur	81	84.5	84	84.5	72.5	43	82.5	81.5	79.5	71.5	77.5	79.5	74	78
45R502	Lodelinsart	74	80.5	85.5	81.5	64.5	31	91	79	67.5	57.5	73	65.5	70	70

Interpolated spatial average in :
Brussels	76	71	71	77	66	23	40	83	67	63	76	74	72	76
Flanders	81	77	81	80	65	41	51	85	69	73	85	83	73	84
Wallonia	79	84	86	83	65	59	79	83	69	70	76	79	72	75
Belgium	80	81	84	81	65	51	66	84	69	71	80	80	73	79

% 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