O3, last 14 days

O₃ concentrations per day (µg/m³), 25/05/2026 - 07/06/2026

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
[O₃]"ozone day" : day with at least one exceedance in Belgium of the EU threshold for information of the public (180 μg/m3)

Code city 25/05[O₃]
26/05[O₃]
27/05 28/05 29/05 30/05 31/05 01/06 02/06 03/06 04/06 05/06 06/06 07/06

41B011 Sint-Agatha-Berchem 124.5 177 127 129.5 130 102 94 82 73 66 71.5 60.5 75.5 76

41MEU1 Neder-Over-Heembeek 125.5 162.5 122.5 136.5 126.5 94.5 91 80.5 67 59 67 59 74.5 70

41N043 Voorhaven (Haren) 122 145.5 111.5 120 118.5 88 91 75.5 64.5 57.5 64.5 58 68.5 68.5

41R001 Sint-Jans-Molenbeek 126.5 166 128 130.5 132 103.5 94.5 80.5 69.5 65.5 65 61.5 71.5 72

41R012 Ukkel 131.5 171.5 121 117.5 129 93.5 84.5 78 71 61.5 70 60.5 72.5 73.5

42N016 Dessel 147 156.5 118.5 141 149 133 119 100.5 75 67 70.5 67 83 82

42N027 Bree 148.5 142.5 115 131 147.5 132.5 119 101.5 89 74.5 77.5 71 85.5 87

42N035 Aarschot 140.5 140 122 145.5 150 121 106.5 95.5 85.5 74 74.5 71.5 81.5 84.5

42N040 Sint-Pieters-Leeuw 124 166 126.5 126 129.5 110 84.5 81.5 74.5 66.5 70 69.5 78 76.5

42N046 Gellik 148 147 128.5 129 142 117 111 100 87.5 72.5 80 69 81.5 87.5

42N047 Hasselt 144.5 143 118.5 138 142.5 115 111.5 96 86 71.5 71 64.5 79.5 84.5

42R801 Borgerhout 125 188 120.5 68.5 NA 122.5 107 92 74.5 72 72 67.5 77.5 81

42R811 Schoten 127.5 180 120 144.5 141.5 133.5 106 95 75.5 76 74.5 65.5 83.5 84

42R842 Mechelen (Hendrik Speecqvest) 121 172 114 133.5 124 101 95.5 80 69.5 64.5 65.5 62.5 77.5 74

44M705 Roeselare (Haven) 186 184.5 153 145 129.5 141 90.5 82 83 72 75.5 91.5 80.5 82.5

44N012 Moerkerke 159.5 185.5 122 144.5 133 151 90 77.5 80.5 71.5 78.5 90 80 80

44N029 Houtem (Veurne) 158.5 194.5 122 147.5 119.5 136.5 80.5 84 81.5 68 73 92 77 74

44R701 Gent (Baudelopark) 175 202.5 149.5 149 142.5 141 97.5 89.5 77.5 72.5 74.5 82 81 81

44R710 Destelbergen 172 197.5 147.5 150.5 144 134 96.5 91 80 76 76.5 81.5 80 84

43N060 Havinnes 120 135 135 130 111 168.5 79 76 66 59 59.5 73 70 68.5

43N064 Rixensart 133 145.5 120 127.5 132.5 97 87.5 88 80 70.5 76 68 79.5 84.5

43N066 Eupen 140.5 131 120.5 118 121 101 95.5 88.5 69.5 62.5 69 59 77 78

43N070 Mons NA 147 127 122.5 104.5 94 60 64 58 49 54 49 62.5 65.5

43N073 Vezin 130 129 135.5 121.5 126 108.5 88 84 74 64.5 69.5 61 76.5 79

43N085 Vielsalm 118 114.5 123 114.5 124.5 70 75.5 79 67 58 58.5 52.5 75 74.5

43N093 Sinsin 140.5 137 130.5 126 123.5 115.5 93 86.5 78 65.5 66.5 58.5 76 82

43N100 Dourbes 130.5 123 155 126 130.5 131 92.5 88 81.5 72.5 72.5 68 83 87.5

43N113 Saint-Ode 129 132.5 127.5 117 117.5 112.5 95 84 70.5 66 75.5 58.5 82.5 85.5

43N121 Offagne NA NA 118.5 117.5 107 112 82.5 NA 64.5 59.5 58 54 76.5 76.5

43N132 Habay-La-Neuve 120.5 136.5 135.5 105.5 120.5 117.5 83.5 83.5 65 61 67.5 57.5 77.5 82.5

43R221 Herstal 148 141 127 119 126.5 110.5 95 95.5 87.5 66 65 61.5 78.5 86.5

43R222 Liège (ISSeP) 147.5 145 134 124 144 107 101.5 96 93 71.5 71 66.5 76 86

43R240 Engis 135.5 138.5 127.5 119.5 117 83.5 86.5 83.5 76 60.5 58.5 57.5 68.5 75

43R401 Namur 127.5 124 132.5 120.5 125 112.5 92.5 84.5 79 69 72.5 64.5 76 82.5

45R502 Lodelinsart 131 132 128 133 116 104 NA 75 61 58 57.5 52.5 70.5 67

Interpolated spatial average in :

Brussels 126 157 121 125 128 95 90 80 71 64 69 62 72 74

Flanders 141 160 124 137 132 124 97 88 78 71 73 73 78 80

Wallonia 124 129 129 118 119 112 83 81 70 63 65 60 74 79

Belgium 131 143 126 126 125 117 89 84 73 67 69 66 76 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 <1% 13% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Wallonia 0% <1% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Belgium <1% 7% 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	25/05[O₃]	26/05[O₃]	27/05	28/05	29/05	30/05	31/05	01/06	02/06	03/06	04/06	05/06	06/06	07/06
41B011	Sint-Agatha-Berchem	124.5	177	127	129.5	130	102	94	82	73	66	71.5	60.5	75.5	76
41MEU1	Neder-Over-Heembeek	125.5	162.5	122.5	136.5	126.5	94.5	91	80.5	67	59	67	59	74.5	70
41N043	Voorhaven (Haren)	122	145.5	111.5	120	118.5	88	91	75.5	64.5	57.5	64.5	58	68.5	68.5
41R001	Sint-Jans-Molenbeek	126.5	166	128	130.5	132	103.5	94.5	80.5	69.5	65.5	65	61.5	71.5	72
41R012	Ukkel	131.5	171.5	121	117.5	129	93.5	84.5	78	71	61.5	70	60.5	72.5	73.5
42N016	Dessel	147	156.5	118.5	141	149	133	119	100.5	75	67	70.5	67	83	82
42N027	Bree	148.5	142.5	115	131	147.5	132.5	119	101.5	89	74.5	77.5	71	85.5	87
42N035	Aarschot	140.5	140	122	145.5	150	121	106.5	95.5	85.5	74	74.5	71.5	81.5	84.5
42N040	Sint-Pieters-Leeuw	124	166	126.5	126	129.5	110	84.5	81.5	74.5	66.5	70	69.5	78	76.5
42N046	Gellik	148	147	128.5	129	142	117	111	100	87.5	72.5	80	69	81.5	87.5
42N047	Hasselt	144.5	143	118.5	138	142.5	115	111.5	96	86	71.5	71	64.5	79.5	84.5
42R801	Borgerhout	125	188	120.5	68.5	NA	122.5	107	92	74.5	72	72	67.5	77.5	81
42R811	Schoten	127.5	180	120	144.5	141.5	133.5	106	95	75.5	76	74.5	65.5	83.5	84
42R842	Mechelen (Hendrik Speecqvest)	121	172	114	133.5	124	101	95.5	80	69.5	64.5	65.5	62.5	77.5	74
44M705	Roeselare (Haven)	186	184.5	153	145	129.5	141	90.5	82	83	72	75.5	91.5	80.5	82.5
44N012	Moerkerke	159.5	185.5	122	144.5	133	151	90	77.5	80.5	71.5	78.5	90	80	80
44N029	Houtem (Veurne)	158.5	194.5	122	147.5	119.5	136.5	80.5	84	81.5	68	73	92	77	74
44R701	Gent (Baudelopark)	175	202.5	149.5	149	142.5	141	97.5	89.5	77.5	72.5	74.5	82	81	81
44R710	Destelbergen	172	197.5	147.5	150.5	144	134	96.5	91	80	76	76.5	81.5	80	84
43N060	Havinnes	120	135	135	130	111	168.5	79	76	66	59	59.5	73	70	68.5
43N064	Rixensart	133	145.5	120	127.5	132.5	97	87.5	88	80	70.5	76	68	79.5	84.5
43N066	Eupen	140.5	131	120.5	118	121	101	95.5	88.5	69.5	62.5	69	59	77	78
43N070	Mons	NA	147	127	122.5	104.5	94	60	64	58	49	54	49	62.5	65.5
43N073	Vezin	130	129	135.5	121.5	126	108.5	88	84	74	64.5	69.5	61	76.5	79
43N085	Vielsalm	118	114.5	123	114.5	124.5	70	75.5	79	67	58	58.5	52.5	75	74.5
43N093	Sinsin	140.5	137	130.5	126	123.5	115.5	93	86.5	78	65.5	66.5	58.5	76	82
43N100	Dourbes	130.5	123	155	126	130.5	131	92.5	88	81.5	72.5	72.5	68	83	87.5
43N113	Saint-Ode	129	132.5	127.5	117	117.5	112.5	95	84	70.5	66	75.5	58.5	82.5	85.5
43N121	Offagne	NA	NA	118.5	117.5	107	112	82.5	NA	64.5	59.5	58	54	76.5	76.5
43N132	Habay-La-Neuve	120.5	136.5	135.5	105.5	120.5	117.5	83.5	83.5	65	61	67.5	57.5	77.5	82.5
43R221	Herstal	148	141	127	119	126.5	110.5	95	95.5	87.5	66	65	61.5	78.5	86.5
43R222	Liège (ISSeP)	147.5	145	134	124	144	107	101.5	96	93	71.5	71	66.5	76	86
43R240	Engis	135.5	138.5	127.5	119.5	117	83.5	86.5	83.5	76	60.5	58.5	57.5	68.5	75
43R401	Namur	127.5	124	132.5	120.5	125	112.5	92.5	84.5	79	69	72.5	64.5	76	82.5
45R502	Lodelinsart	131	132	128	133	116	104	NA	75	61	58	57.5	52.5	70.5	67

Interpolated spatial average in :
Brussels	126	157	121	125	128	95	90	80	71	64	69	62	72	74
Flanders	141	160	124	137	132	124	97	88	78	71	73	73	78	80
Wallonia	124	129	129	118	119	112	83	81	70	63	65	60	74	79
Belgium	131	143	126	126	125	117	89	84	73	67	69	66	76	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	<1%	13%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Wallonia	0%	<1%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%	0%
Belgium	<1%	7%	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