O3, last 14 days

O₃ concentrations per day (µg/m³), 20/07/2026 - 02/08/2026

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 20/07 21/07 22/07 23/07 24/07 25/07 26/07 27/07 28/07 29/07 30/07 31/07 01/08 02/08

41B011 Sint-Agatha-Berchem 90 93.5 78.5 72.5 102 135 75.5 75.5 116 132.5 95 94 105 130.5

41MEU1 Neder-Over-Heembeek 90.5 94.5 78 72.5 103 134 73 77 110.5 125.5 90.5 95.5 101 130.5

41N043 Voorhaven (Haren) 82 79.5 67.5 63 94 124.5 67 70 100 114.5 84.5 87 94 122

41R001 Sint-Jans-Molenbeek 85 86.5 73.5 66 100.5 127 70.5 69.5 104 119 91.5 86.5 97.5 123

41R012 Ukkel 92 97.5 78 71 106 134 75 76.5 106 125 94 92.5 104 127.5

42N016 Dessel 93.5 99.5 67.5 87 100.5 151.5 89.5 74.5 121.5 136 118.5 101.5 106.5 140.5

42N027 Bree 97 102 81 97 98 159 90 83 138 139 134 123 110 133

42N035 Aarschot 98.5 101.5 80 86.5 53.5 NA NA 80 124 149 112 108.5 111 140

42N040 Sint-Pieters-Leeuw 87.5 92.5 80.5 72 108 134 71 78 112.5 131 96 91 109.5 128.5

42N046 Gellik 94 100 83.5 99.5 105.5 149.5 90.5 81.5 132.5 147.5 125 109.5 108.5 130

42N047 Hasselt 94 97.5 80.5 91 95.5 149.5 93 78 128 137 121.5 103.5 103 130

42R801 Borgerhout 87 85.5 73 70.5 130 130.5 79 73 131 134.5 113.5 95.5 105 144.5

42R811 Schoten 87.5 89 78.5 74 135 135 81 73.5 137.5 141 111.5 99.5 104.5 147.5

42R842 Mechelen (Hendrik Speecqvest) 86 92.5 71.5 67 106.5 133 79 71 114.5 118.5 91 90 98 127.5

44M705 Roeselare (Haven) 82 91 84 72.5 131 140.5 75.5 99.5 128.5 139.5 107.5 93 120.5 142

44N012 Moerkerke 82 86.5 84.5 71 27.5 125.5 76 88.5 121 150.5 115.5 91 116.5 138.5

44N029 Houtem (Veurne) 80.5 80.5 83.5 76.5 151.5 126 68 91.5 105 160 102.5 94.5 112.5 140

44R701 Gent (Baudelopark) 80.5 84 79.5 69.5 115.5 126 66 87 118.5 142 105.5 91.5 128 157.5

44R710 Destelbergen 85.5 89.5 82.5 74 121 134.5 73 87 126.5 145.5 110 97 128 161.5

43N060 Havinnes 82.5 83 78 67.5 119.5 129 58.5 85 106.5 133 95 87 106 130.5

43N064 Rixensart 100 111.5 84.5 80 120 142 80.5 83 121 137.5 106.5 101.5 108.5 129.5

43N066 Eupen 89 94.5 82 94 82.5 123 91 76.5 116.5 130 125 127.5 102 111.5

43N070 Mons 83.5 92.5 79 69 105 122 53.5 74.5 96.5 107 69.5 84 102 118

43N073 Vezin 93 98.5 81.5 86.5 88 140.5 79 87 109 124 104.5 99.5 98.5 120.5

43N085 Vielsalm 85.5 93.5 84 92 84.5 115.5 95.5 81 99.5 117.5 126 126.5 106.5 116

43N093 Sinsin 93 88.5 90 91.5 88.5 128 94.5 88.5 108 130 113 118.5 112.5 123

43N100 Dourbes 104 113.5 93.5 92 110.5 138.5 90 88.5 103 132 124 101 108.5 135

43N113 Saint-Ode 87 95 90.5 97 97 121 101 86.5 114 124 127 135.5 111.5 123

43N121 Offagne 90.5 88 90 93 92 116.5 100.5 76.5 99.5 125 120 126 108.5 128.5

43N132 Habay-La-Neuve 83.5 91.5 84.5 92 87 117.5 61 72 118.5 127 122 133.5 104 127

43R221 Herstal 92.5 95 85.5 93.5 104.5 139 87.5 83 120.5 126 116 119 101.5 116

43R222 Liège (ISSeP) 90.5 92.5 74 89.5 98.5 135.5 85.5 79.5 121.5 125 119 119.5 106 119

43R240 Engis 90.5 88.5 81 90 84.5 130 71 78.5 105.5 121.5 108.5 93 103.5 113.5

43R401 Namur 90 98.5 83.5 81.5 89 141.5 83.5 89.5 103.5 123.5 110.5 95.5 97.5 115

45R502 Lodelinsart 95 110.5 81.5 77.5 98.5 129 72 78.5 96 123.5 56.5 NA 100 121.5

Interpolated spatial average in :

Brussels 90 92 77 70 102 130 74 75 109 123 93 93 101 126

Flanders 88 91 80 78 115 132 77 83 119 136 109 97 109 136

Wallonia 89 92 84 85 96 123 80 81 105 122 110 108 103 122

Belgium 88 92 82 82 104 127 79 82 112 128 109 103 106 128

% 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	20/07	21/07	22/07	23/07	24/07	25/07	26/07	27/07	28/07	29/07	30/07	31/07	01/08	02/08
41B011	Sint-Agatha-Berchem	90	93.5	78.5	72.5	102	135	75.5	75.5	116	132.5	95	94	105	130.5
41MEU1	Neder-Over-Heembeek	90.5	94.5	78	72.5	103	134	73	77	110.5	125.5	90.5	95.5	101	130.5
41N043	Voorhaven (Haren)	82	79.5	67.5	63	94	124.5	67	70	100	114.5	84.5	87	94	122
41R001	Sint-Jans-Molenbeek	85	86.5	73.5	66	100.5	127	70.5	69.5	104	119	91.5	86.5	97.5	123
41R012	Ukkel	92	97.5	78	71	106	134	75	76.5	106	125	94	92.5	104	127.5
42N016	Dessel	93.5	99.5	67.5	87	100.5	151.5	89.5	74.5	121.5	136	118.5	101.5	106.5	140.5
42N027	Bree	97	102	81	97	98	159	90	83	138	139	134	123	110	133
42N035	Aarschot	98.5	101.5	80	86.5	53.5	NA	NA	80	124	149	112	108.5	111	140
42N040	Sint-Pieters-Leeuw	87.5	92.5	80.5	72	108	134	71	78	112.5	131	96	91	109.5	128.5
42N046	Gellik	94	100	83.5	99.5	105.5	149.5	90.5	81.5	132.5	147.5	125	109.5	108.5	130
42N047	Hasselt	94	97.5	80.5	91	95.5	149.5	93	78	128	137	121.5	103.5	103	130
42R801	Borgerhout	87	85.5	73	70.5	130	130.5	79	73	131	134.5	113.5	95.5	105	144.5
42R811	Schoten	87.5	89	78.5	74	135	135	81	73.5	137.5	141	111.5	99.5	104.5	147.5
42R842	Mechelen (Hendrik Speecqvest)	86	92.5	71.5	67	106.5	133	79	71	114.5	118.5	91	90	98	127.5
44M705	Roeselare (Haven)	82	91	84	72.5	131	140.5	75.5	99.5	128.5	139.5	107.5	93	120.5	142
44N012	Moerkerke	82	86.5	84.5	71	27.5	125.5	76	88.5	121	150.5	115.5	91	116.5	138.5
44N029	Houtem (Veurne)	80.5	80.5	83.5	76.5	151.5	126	68	91.5	105	160	102.5	94.5	112.5	140
44R701	Gent (Baudelopark)	80.5	84	79.5	69.5	115.5	126	66	87	118.5	142	105.5	91.5	128	157.5
44R710	Destelbergen	85.5	89.5	82.5	74	121	134.5	73	87	126.5	145.5	110	97	128	161.5
43N060	Havinnes	82.5	83	78	67.5	119.5	129	58.5	85	106.5	133	95	87	106	130.5
43N064	Rixensart	100	111.5	84.5	80	120	142	80.5	83	121	137.5	106.5	101.5	108.5	129.5
43N066	Eupen	89	94.5	82	94	82.5	123	91	76.5	116.5	130	125	127.5	102	111.5
43N070	Mons	83.5	92.5	79	69	105	122	53.5	74.5	96.5	107	69.5	84	102	118
43N073	Vezin	93	98.5	81.5	86.5	88	140.5	79	87	109	124	104.5	99.5	98.5	120.5
43N085	Vielsalm	85.5	93.5	84	92	84.5	115.5	95.5	81	99.5	117.5	126	126.5	106.5	116
43N093	Sinsin	93	88.5	90	91.5	88.5	128	94.5	88.5	108	130	113	118.5	112.5	123
43N100	Dourbes	104	113.5	93.5	92	110.5	138.5	90	88.5	103	132	124	101	108.5	135
43N113	Saint-Ode	87	95	90.5	97	97	121	101	86.5	114	124	127	135.5	111.5	123
43N121	Offagne	90.5	88	90	93	92	116.5	100.5	76.5	99.5	125	120	126	108.5	128.5
43N132	Habay-La-Neuve	83.5	91.5	84.5	92	87	117.5	61	72	118.5	127	122	133.5	104	127
43R221	Herstal	92.5	95	85.5	93.5	104.5	139	87.5	83	120.5	126	116	119	101.5	116
43R222	Liège (ISSeP)	90.5	92.5	74	89.5	98.5	135.5	85.5	79.5	121.5	125	119	119.5	106	119
43R240	Engis	90.5	88.5	81	90	84.5	130	71	78.5	105.5	121.5	108.5	93	103.5	113.5
43R401	Namur	90	98.5	83.5	81.5	89	141.5	83.5	89.5	103.5	123.5	110.5	95.5	97.5	115
45R502	Lodelinsart	95	110.5	81.5	77.5	98.5	129	72	78.5	96	123.5	56.5	NA	100	121.5

Interpolated spatial average in :
Brussels	90	92	77	70	102	130	74	75	109	123	93	93	101	126
Flanders	88	91	80	78	115	132	77	83	119	136	109	97	109	136
Wallonia	89	92	84	85	96	123	80	81	105	122	110	108	103	122
Belgium	88	92	82	82	104	127	79	82	112	128	109	103	106	128

% 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