O3, last 14 days

O₃ concentrations per day (µg/m³), 13/04/2026 - 26/04/2026

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 13/04 14/04 15/04 16/04 17/04 18/04 19/04 20/04 21/04 22/04 23/04 24/04 25/04 26/04

41B011 Sint-Agatha-Berchem 68 88.5 93.5 90.5 93 47 82 78 89.5 102.5 98.5 91 94 96.5

41MEU1 Neder-Over-Heembeek 75.5 90 99 90 95.5 52 87 81.5 92 106.5 103 92.5 93 100.5

41N043 Voorhaven (Haren) 63.5 82 87.5 86 88.5 46 85.5 78.5 88.5 100 95.5 86 91.5 96.5

41R001 Sint-Jans-Molenbeek 55.5 78.5 89.5 83.5 87.5 49 79 71 82.5 95.5 89.5 82.5 84 93.5

41R012 Ukkel 73.5 90.5 99 94 98.5 57 90 86.5 96.5 107.5 104.5 101 98 105.5

42N016 Dessel 85 94 107 92.5 102.5 68 95.5 89.5 100.5 112 111 107 107.5 110.5

42N027 Bree 87 96 107.5 NA 107 76.5 94 94 97.5 103 107.5 108 108 107

42N035 Aarschot 91 97 112 95 102.5 63 96 94 101.5 110.5 105 103 108.5 109.5

42N040 Sint-Pieters-Leeuw 68.5 90.5 94 93 97 52.5 84 83.5 92.5 107 103 100 92.5 101

42N046 Gellik 90.5 91 106.5 95.5 107 81 94 93 93 110 106.5 103 105 106.5

42N047 Hasselt 85 91.5 106 92 102 65.5 93.5 91 96 109.5 104.5 100.5 100 106

42R801 Borgerhout 77.5 95 103.5 98 98.5 65 92 85 94.5 108 106 89 87 105.5

42R811 Schoten 82 101.5 108.5 101 104 59.5 92 54.5 95.5 65 108 95 97 106.5

42R842 Mechelen (Hendrik Speecqvest) 72.5 86.5 97.5 88.5 87.5 55.5 88.5 78 89 101.5 96.5 91 93.5 96.5

44M705 Roeselare (Haven) 79 102.5 95.5 91 93.5 90.5 88 88.5 91.5 111 98.5 96.5 92 114

44N012 Moerkerke 81.5 97.5 98.5 87 93.5 81 92.5 89 92 107 102.5 99.5 96 93

44N029 Houtem (Veurne) 88 92.5 76.5 84 88 97 90.5 89.5 87.5 97 96.5 97.5 97 95.5

44R701 Gent (Baudelopark) 71 98.5 96.5 89.5 91.5 75 87 87.5 93.5 109.5 99 93.5 101 99

44R710 Destelbergen 75 98 98.5 95 95.5 67.5 88 88 95 110 96 87 99.5 104.5

43N060 Havinnes 62 89 83 82.5 83 63 78 81 81.5 97 101 87.5 95.5 105.5

43N064 Rixensart 82 92 104.5 98 104.5 61 93 93 99.5 117.5 110 112 102.5 110

43N066 Eupen 81 92 98.5 86.5 104 89.5 84.5 88.5 81 108 100.5 100 111.5 93

43N070 Mons 59.5 86.5 85.5 81.5 92.5 56 85.5 89.5 94.5 110 106.5 104 101.5 109

43N073 Vezin 76.5 91 103.5 85.5 96.5 66 88.5 88.5 86.5 107 106 103 95 109

43N085 Vielsalm 89 87 96.5 95 105 91.5 85 92 86 106.5 105 107 103 101.5

43N093 Sinsin 72.5 88.5 101 93 94 89.5 91 91 83 107 110.5 104.5 101.5 98.5

43N100 Dourbes 81 94.5 109.5 100.5 104.5 97.5 94.5 100 96 115.5 120.5 116.5 111.5 117

43N113 Saint-Ode 91.5 87 98.5 95.5 103.5 93 92.5 89.5 88.5 107.5 108 106 104 107.5

43N121 Offagne 73 53 86 75.5 65.5 70 NA NA 71.5 88.5 97 97.5 91 92.5

43N132 Habay-La-Neuve 86.5 84 87.5 94 94.5 97 92 85.5 89.5 106 103 108.5 104 106.5

43R221 Herstal 83.5 84.5 108.5 91 103 82.5 92 92.5 89 108 116 99.5 100 104

43R222 Liège (ISSeP) 84.5 87 106 91 103 79.5 92 90.5 87.5 113 108.5 101.5 99.5 101

43R240 Engis 80.5 85.5 103.5 87 96 67 87 89 87.5 110 99.5 102 94 105.5

43R401 Namur 78 91 102 92.5 97.5 64 87.5 88.5 83.5 102 101 92.5 94 108.5

45R502 Lodelinsart 71.5 84 95 75 87 58.5 84 87 87.5 104.5 102.5 101 95.5 100

Interpolated spatial average in :

Brussels 70 87 95 90 94 49 86 81 92 104 100 93 93 100

Flanders 78 95 99 91 96 67 90 88 93 106 101 96 97 102

Wallonia 75 84 95 88 93 74 87 89 87 104 103 101 98 101

Belgium 76 89 97 89 94 71 89 89 90 105 102 99 97 102

% 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	13/04	14/04	15/04	16/04	17/04	18/04	19/04	20/04	21/04	22/04	23/04	24/04	25/04	26/04
41B011	Sint-Agatha-Berchem	68	88.5	93.5	90.5	93	47	82	78	89.5	102.5	98.5	91	94	96.5
41MEU1	Neder-Over-Heembeek	75.5	90	99	90	95.5	52	87	81.5	92	106.5	103	92.5	93	100.5
41N043	Voorhaven (Haren)	63.5	82	87.5	86	88.5	46	85.5	78.5	88.5	100	95.5	86	91.5	96.5
41R001	Sint-Jans-Molenbeek	55.5	78.5	89.5	83.5	87.5	49	79	71	82.5	95.5	89.5	82.5	84	93.5
41R012	Ukkel	73.5	90.5	99	94	98.5	57	90	86.5	96.5	107.5	104.5	101	98	105.5
42N016	Dessel	85	94	107	92.5	102.5	68	95.5	89.5	100.5	112	111	107	107.5	110.5
42N027	Bree	87	96	107.5	NA	107	76.5	94	94	97.5	103	107.5	108	108	107
42N035	Aarschot	91	97	112	95	102.5	63	96	94	101.5	110.5	105	103	108.5	109.5
42N040	Sint-Pieters-Leeuw	68.5	90.5	94	93	97	52.5	84	83.5	92.5	107	103	100	92.5	101
42N046	Gellik	90.5	91	106.5	95.5	107	81	94	93	93	110	106.5	103	105	106.5
42N047	Hasselt	85	91.5	106	92	102	65.5	93.5	91	96	109.5	104.5	100.5	100	106
42R801	Borgerhout	77.5	95	103.5	98	98.5	65	92	85	94.5	108	106	89	87	105.5
42R811	Schoten	82	101.5	108.5	101	104	59.5	92	54.5	95.5	65	108	95	97	106.5
42R842	Mechelen (Hendrik Speecqvest)	72.5	86.5	97.5	88.5	87.5	55.5	88.5	78	89	101.5	96.5	91	93.5	96.5
44M705	Roeselare (Haven)	79	102.5	95.5	91	93.5	90.5	88	88.5	91.5	111	98.5	96.5	92	114
44N012	Moerkerke	81.5	97.5	98.5	87	93.5	81	92.5	89	92	107	102.5	99.5	96	93
44N029	Houtem (Veurne)	88	92.5	76.5	84	88	97	90.5	89.5	87.5	97	96.5	97.5	97	95.5
44R701	Gent (Baudelopark)	71	98.5	96.5	89.5	91.5	75	87	87.5	93.5	109.5	99	93.5	101	99
44R710	Destelbergen	75	98	98.5	95	95.5	67.5	88	88	95	110	96	87	99.5	104.5
43N060	Havinnes	62	89	83	82.5	83	63	78	81	81.5	97	101	87.5	95.5	105.5
43N064	Rixensart	82	92	104.5	98	104.5	61	93	93	99.5	117.5	110	112	102.5	110
43N066	Eupen	81	92	98.5	86.5	104	89.5	84.5	88.5	81	108	100.5	100	111.5	93
43N070	Mons	59.5	86.5	85.5	81.5	92.5	56	85.5	89.5	94.5	110	106.5	104	101.5	109
43N073	Vezin	76.5	91	103.5	85.5	96.5	66	88.5	88.5	86.5	107	106	103	95	109
43N085	Vielsalm	89	87	96.5	95	105	91.5	85	92	86	106.5	105	107	103	101.5
43N093	Sinsin	72.5	88.5	101	93	94	89.5	91	91	83	107	110.5	104.5	101.5	98.5
43N100	Dourbes	81	94.5	109.5	100.5	104.5	97.5	94.5	100	96	115.5	120.5	116.5	111.5	117
43N113	Saint-Ode	91.5	87	98.5	95.5	103.5	93	92.5	89.5	88.5	107.5	108	106	104	107.5
43N121	Offagne	73	53	86	75.5	65.5	70	NA	NA	71.5	88.5	97	97.5	91	92.5
43N132	Habay-La-Neuve	86.5	84	87.5	94	94.5	97	92	85.5	89.5	106	103	108.5	104	106.5
43R221	Herstal	83.5	84.5	108.5	91	103	82.5	92	92.5	89	108	116	99.5	100	104
43R222	Liège (ISSeP)	84.5	87	106	91	103	79.5	92	90.5	87.5	113	108.5	101.5	99.5	101
43R240	Engis	80.5	85.5	103.5	87	96	67	87	89	87.5	110	99.5	102	94	105.5
43R401	Namur	78	91	102	92.5	97.5	64	87.5	88.5	83.5	102	101	92.5	94	108.5
45R502	Lodelinsart	71.5	84	95	75	87	58.5	84	87	87.5	104.5	102.5	101	95.5	100

Interpolated spatial average in :
Brussels	70	87	95	90	94	49	86	81	92	104	100	93	93	100
Flanders	78	95	99	91	96	67	90	88	93	106	101	96	97	102
Wallonia	75	84	95	88	93	74	87	89	87	104	103	101	98	101
Belgium	76	89	97	89	94	71	89	89	90	105	102	99	97	102

% 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