O3, last 14 days

O₃ concentrations per day (µg/m³), 16/03/2026 - 29/03/2026

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 16/03 17/03 18/03 19/03 20/03 21/03 22/03 23/03 24/03 25/03 26/03 27/03 28/03 29/03

41B011 Sint-Agatha-Berchem 77.5 82 89.5 110.5 91.5 76 90.5 85.5 97 82 79.5 78.5 83.5 81

41MEU1 Neder-Over-Heembeek 64 NA 85 108.5 42.5 74 88 82 89.5 80 79.5 73 84.5 76

41N043 Voorhaven (Haren) 64 66.5 78.5 100 13 NA NA 76 83 75 76.5 62.5 80 73

41R001 Sint-Jans-Molenbeek 60 71 80.5 91 78.5 67 80 66.5 86 75.5 69.5 62 71 72

41R012 Ukkel 80 80.5 87.5 107.5 92.5 75.5 92 85 96.5 82.5 79 78.5 84.5 77

42N016 Dessel 82 79.5 90 107 96 81.5 92 95.5 99 82.5 84 80 87.5 80

42N027 Bree 80 79 86 109 95 81 86 100.5 62.5 81.5 73 84.5 86.5 85

42N035 Aarschot 67.5 NA NA NA 101 83.5 95 92.5 104.5 85.5 85.5 85 87.5 84.5

42N040 Sint-Pieters-Leeuw 66 NA NA NA 91 75.5 89 83 91 79.5 78 78 82 78

42N046 Gellik NA NA NA 92.5 46 NA NA NA 90.5 88 81.5 85 89.5 88

42N047 Hasselt 78 78.5 86 106 95 76 93 99 93.5 84.5 80 84 88.5 85.5

42R801 Borgerhout 79.5 78.5 83 104 94 79.5 90.5 73.5 92 83.5 80.5 77 85 79.5

42R811 Schoten 66.5 NA NA NA NA NA NA 74.5 95.5 88 82 77.5 89.5 81.5

42R842 Mechelen (Hendrik Speecqvest) 68.5 NA NA NA 79 70.5 84 72.5 93.5 79.5 74.5 73.5 82.5 76

44M705 Roeselare (Haven) 80 86 86.5 94.5 89 67 NA 82 99 86.5 82.5 79 88.5 83.5

44N012 Moerkerke 83 89.5 88.5 97 85.5 61.5 79.5 82 93.5 86.5 83 81 86 83.5

44N029 Houtem (Veurne) 80 85 88 81 70.5 71 46 80 88.5 83 83 80.5 86 81

44R701 Gent (Baudelopark) 77 89.5 89 105 96 69 94 85.5 107 85 77.5 76 85 81

44R710 Destelbergen 80 87 91 107.5 90 79.5 95.5 88.5 105 87.5 81 79 86.5 81

43N060 Havinnes 69 74 75.5 96.5 91 68.5 76 78 81.5 71 72.5 68.5 73 68

43N064 Rixensart 84.5 83 92 118.5 100.5 86.5 100 93.5 100 86 84 83 89.5 85.5

43N066 Eupen 70 69 82 100 84.5 83.5 93 95 94.5 86 69.5 80 78.5 81

43N070 Mons 75 73.5 87.5 115.5 105.5 80 89 82 83 77 78 65.5 85 73

43N073 Vezin 80 79 87.5 101 105 78.5 86 95 95.5 82.5 77.5 83 84 81

43N085 Vielsalm 68 71.5 82.5 100 104.5 88 93 95 93.5 79 75 75.5 74 77.5

43N093 Sinsin 78.5 79 85.5 98 93.5 90 92 99 100 85.5 80 82.5 88 86

43N100 Dourbes 87.5 86 95.5 109.5 108.5 100 95.5 107.5 106 90 86 89.5 94.5 89

43N113 Saint-Ode 80 78 88.5 102.5 108 92 93 98 100 90 86 86.5 85.5 85

43N121 Offagne 62 68.5 78.5 84.5 82 76.5 79 80 91.5 76 57 70 77 77.5

43N132 Habay-La-Neuve 70.5 75 79.5 100.5 103 89 91 93.5 96.5 82.5 77 80 82 78.5

43R221 Herstal 72.5 71 84.5 92 88 81 90 94.5 93.5 87 76 77.5 84.5 85

43R222 Liège (ISSeP) 73 77 87 101 93 86 93.5 95.5 97.5 89.5 78.5 82.5 87.5 87.5

43R240 Engis 75 76 86.5 100 90 81 91 94.5 95 85 71 82 84 80.5

43R401 Namur 78.5 78.5 79 95 89.5 79.5 84.5 93 96.5 86 79.5 83 85 82.5

45R502 Lodelinsart 67.5 73.5 80 100.5 98.5 74.5 87 82 91.5 79 74 73 81.5 75

Interpolated spatial average in :

Brussels 77 76 86 107 89 72 87 80 92 81 78 74 83 77

Flanders 83 85 92 107 93 74 85 90 98 87 81 81 86 81

Wallonia 75 79 87 103 98 83 88 93 96 83 77 79 82 80

Belgium 79 82 89 105 96 79 86 91 97 85 79 80 84 80

% 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	16/03	17/03	18/03	19/03	20/03	21/03	22/03	23/03	24/03	25/03	26/03	27/03	28/03	29/03
41B011	Sint-Agatha-Berchem	77.5	82	89.5	110.5	91.5	76	90.5	85.5	97	82	79.5	78.5	83.5	81
41MEU1	Neder-Over-Heembeek	64	NA	85	108.5	42.5	74	88	82	89.5	80	79.5	73	84.5	76
41N043	Voorhaven (Haren)	64	66.5	78.5	100	13	NA	NA	76	83	75	76.5	62.5	80	73
41R001	Sint-Jans-Molenbeek	60	71	80.5	91	78.5	67	80	66.5	86	75.5	69.5	62	71	72
41R012	Ukkel	80	80.5	87.5	107.5	92.5	75.5	92	85	96.5	82.5	79	78.5	84.5	77
42N016	Dessel	82	79.5	90	107	96	81.5	92	95.5	99	82.5	84	80	87.5	80
42N027	Bree	80	79	86	109	95	81	86	100.5	62.5	81.5	73	84.5	86.5	85
42N035	Aarschot	67.5	NA	NA	NA	101	83.5	95	92.5	104.5	85.5	85.5	85	87.5	84.5
42N040	Sint-Pieters-Leeuw	66	NA	NA	NA	91	75.5	89	83	91	79.5	78	78	82	78
42N046	Gellik	NA	NA	NA	92.5	46	NA	NA	NA	90.5	88	81.5	85	89.5	88
42N047	Hasselt	78	78.5	86	106	95	76	93	99	93.5	84.5	80	84	88.5	85.5
42R801	Borgerhout	79.5	78.5	83	104	94	79.5	90.5	73.5	92	83.5	80.5	77	85	79.5
42R811	Schoten	66.5	NA	NA	NA	NA	NA	NA	74.5	95.5	88	82	77.5	89.5	81.5
42R842	Mechelen (Hendrik Speecqvest)	68.5	NA	NA	NA	79	70.5	84	72.5	93.5	79.5	74.5	73.5	82.5	76
44M705	Roeselare (Haven)	80	86	86.5	94.5	89	67	NA	82	99	86.5	82.5	79	88.5	83.5
44N012	Moerkerke	83	89.5	88.5	97	85.5	61.5	79.5	82	93.5	86.5	83	81	86	83.5
44N029	Houtem (Veurne)	80	85	88	81	70.5	71	46	80	88.5	83	83	80.5	86	81
44R701	Gent (Baudelopark)	77	89.5	89	105	96	69	94	85.5	107	85	77.5	76	85	81
44R710	Destelbergen	80	87	91	107.5	90	79.5	95.5	88.5	105	87.5	81	79	86.5	81
43N060	Havinnes	69	74	75.5	96.5	91	68.5	76	78	81.5	71	72.5	68.5	73	68
43N064	Rixensart	84.5	83	92	118.5	100.5	86.5	100	93.5	100	86	84	83	89.5	85.5
43N066	Eupen	70	69	82	100	84.5	83.5	93	95	94.5	86	69.5	80	78.5	81
43N070	Mons	75	73.5	87.5	115.5	105.5	80	89	82	83	77	78	65.5	85	73
43N073	Vezin	80	79	87.5	101	105	78.5	86	95	95.5	82.5	77.5	83	84	81
43N085	Vielsalm	68	71.5	82.5	100	104.5	88	93	95	93.5	79	75	75.5	74	77.5
43N093	Sinsin	78.5	79	85.5	98	93.5	90	92	99	100	85.5	80	82.5	88	86
43N100	Dourbes	87.5	86	95.5	109.5	108.5	100	95.5	107.5	106	90	86	89.5	94.5	89
43N113	Saint-Ode	80	78	88.5	102.5	108	92	93	98	100	90	86	86.5	85.5	85
43N121	Offagne	62	68.5	78.5	84.5	82	76.5	79	80	91.5	76	57	70	77	77.5
43N132	Habay-La-Neuve	70.5	75	79.5	100.5	103	89	91	93.5	96.5	82.5	77	80	82	78.5
43R221	Herstal	72.5	71	84.5	92	88	81	90	94.5	93.5	87	76	77.5	84.5	85
43R222	Liège (ISSeP)	73	77	87	101	93	86	93.5	95.5	97.5	89.5	78.5	82.5	87.5	87.5
43R240	Engis	75	76	86.5	100	90	81	91	94.5	95	85	71	82	84	80.5
43R401	Namur	78.5	78.5	79	95	89.5	79.5	84.5	93	96.5	86	79.5	83	85	82.5
45R502	Lodelinsart	67.5	73.5	80	100.5	98.5	74.5	87	82	91.5	79	74	73	81.5	75

Interpolated spatial average in :
Brussels	77	76	86	107	89	72	87	80	92	81	78	74	83	77
Flanders	83	85	92	107	93	74	85	90	98	87	81	81	86	81
Wallonia	75	79	87	103	98	83	88	93	96	83	77	79	82	80
Belgium	79	82	89	105	96	79	86	91	97	85	79	80	84	80

% 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