Air quality breaches

The National Environmental Standard for Air Quality (NESAQ) threshold for PM10, particles smaller than 10 microns in diameter, has been breached when the daily average PM10 threshold of 50 micrograms per cubic metre (µg/m3) has been exceeded more than once in a 12-month period.

Exceedances over the last five years

Year Ashburton Christchurch Geraldine Kaiapoi Rangiora Timaru Washdyke Waimate
2023 0 2 0 5 2 6 35 0
2022 1 3 0 11 3 3 20 0
2021 0 1 0 3 2 13 30 0
2020 0 8 0 3 4 10 22 0
2019 1 7 1 8 2 12 14 1
2018 2 4 1 2 0 8 1 0

An airshed is no longer described as polluted when the number of exceedances was one or less in each of the last five years.

View the current calendar year totals.

Concentrations on exceedance days in each airshed

Particulate matter (PM) consists of both ”fine” and “coarse” particles. Fine particles (PM2.5) have a diameter smaller than 2.5 µm and are mainly from combustion sources (wood burners, motor vehicles, industrial boilers). Coarse particles (PM2.5-10) have a diameter greater than 2.5 µm and less than 10 µm, and are mainly from dust and marine aerosols.

Bold figures in the following tables indicate a PM10 exceedance of 50 µg/m3 and when PM2.5 also exceeded 25 µg/m3.

Ashburton airshed - Last exceedance on 25/4/2024

This monitoring site is located on Cambridge Street, Ashburton, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Thu 25/4/2024 51 9 42
Fri 24/6/2022 53 47 6
Mon 1/7/2019 59 29 30
Mon 16/07/2018 54 48 6
Fri 22/6/2018 52 41 10
Mon 19/6/2017 53 43 11
Sat 3/6/2017 51 44 7
Fri 26/5/2017 52 - -

Christchurch airshed - Last exceedance on 19/7/2023

Where there is more than one monitoring site, the maximum concentration is reported for the airshed.

These monitoring sites are located in St Albans (Coles Place until 2020, English Park from 2022), which is in a residential area, and Woolston (King Edward Terrace), which is in an industrial/residential area.
Date of exceedance Airshed St Albans Woolston
PM10 PM10 PM2.5 PM10-2.5 PM10 PM2.5 PM10-2.5
Wed 19/7/2023 66 44 39 5 66 26 40
Tue 18/7/2023 60 60 55 5 28 13 15
Tue 5/7/2022 70 70 59 11 57 31 26
Sun 3/7/2022 53 50 45 5 53 45 8
Wed 15/6/2022 52 52 43 9 41 25 16
Fri 25/6/2021 53       53 14 40
Tue 4/8/2020 65 47 31 15 65 31 34
Tue 14/7/2020 54 40 33 7 54 36 17
Tue 16/6/2020 60 22 12 9 60 15 45
Thu 11/6/2020 75 38 28 9 75 32 43
Tue 9/6/2020 57 38 31 8 57 40 17
Mon 8/6/2020 87 87 75 12 75 38 37
Sun 7/6/2020 52 52 46 6 15 10 5
Fri 22/5/2020 54 39 17 22 54 16 39
Wed 27/11/2019 51 20 6 14 51 8 43
Thu 8/8/2019 55 52 46 6 55 38 18
Wed 7/8/2019 59 46 40 6 59 38 20
Sun 28/7/2019 58 45 34 12 58 31 27
Sun 7/7/2019 68 68 59 8 25 19 6
Mon 1/7/2019 57 52 32 20 57 20 37
Fri 28/6/2019 53 53 44 9 43 30 13
Wed 1/8/2018 54 51 30 21 54 21 33
Fri 20/7/2018 53 44 35 10 53 35 18
Sat 23/6/2018 61 56 46 10 61 52 9
Fri 22/6/2018 74 64 51 13 74 50 24
Mon 26/6/2017 60 60 49 11 39 25 14
Sun 25/6/2017 63 63 58 6 35 30 6
Sat 17/6/2017 51 45 38 8 51 38 13
Sun 11/6/2017 59 59 51 8 46 35 10
Sun 14/5/2017 56 56 51 5 36 30 6

Geraldine airshed - Last exceedance on 6/7/2018

This monitoring site is located on Huffey Street, Geraldine, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Fri 1/02/2019 53* 11 42
Fri 6/07/2018 52 41 11
Wed 21/06/2017 59 46 12

*Exceptional event, not counted for breach of NESAQ.

Kaiapoi airshed - Last exceedance on 14/5/2024

This monitoring site is located on Peraki Street, Kaiapoi, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Tue 14/5/2024 58 51 7
Wed 19/7/2023 75 67 8
Tue 18/7/2023 82 75 7
Sat 15/7/2023 57 52 5
Tue 4/7/2023 53 46 7
Sun 11/6/2023 57 51 6
Sun 14/8/2022 60 54 6
Mon 1/8/2022 62 56 6
Sat 16/7/2022 53 47 6
Wed 6/7/2022 59 44 15
Tue 5/7/2022 111 92 19
Sun 3/7/2022 65 58 7
Fri 24/6/2022 53 40 13
Thu 16/6/2022 51 40 11
Wed 15/6/2022 53 43 10
Sun 30/5/2022 51 46 5
Tue 24/5/2022 64 54 10
Wed 14/7/2021 72 64 9
Mon 12/7/2021 56 45 12
Wed 2/6/2021 62 55 7
Mon 10/8/2020 63 55 8
Mon 8/6/2020 88 81 7
Sun 7/6/2020 55 50 5
Wed 7/8/2019 62 54 8
Sun 28/7/2019 63 52 10
Sun 7/7/2019 66 60 6
Tue 2/7/2019 58 48 9
Mon 1/7/2019 76 61 14
Sat 29/6/2019 69 59 9
Fri 28/6/2019 53 44 10
Sat 18/5/2019 59 53 6
Fri 20/7/2018 51 45 6
Sat 23/6/2018 51 45 6
Sat 26/8/2017 59 54 5
Tue 25/7/2017 68 62 6
Mon 24/7/2017 59 55 4
Sun 16/7/2017 54 49 5
Sun 25/06/2017 61 61 0
Sun 18/06/2017 55 54 1
Thu 15/6/2017 53 42 11
Sun 11/6/2017 63 61 2
Sat 10/6/2017 51 45 5
Tue 23/5/2017 52 45 7

Rangiora airshed - Last exceedance on 18/7/2023

This monitoring site is located on Percival Street, Rangiora, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Tue 18/7/023 60 53 7
Mon 17/7/2023 51 45 6
Wed 6/7/2022 55 41 14
Tue 5/7/2022 67 62 5
Sun 3/7/2022 57 56 1
Wed 14/7/2021 55 51 4
Thu 27/5/2021 53 46 7
Mon 10/8/2020 57 50 8
Sat 11/7/2020 58 54 4
Mon 8/6/2020 59 53 6
Sun 7/6/2020 56 53 3
Sun 7/7/2019 69 64 5
Mon 1/7/2019 72 60 12
Sat 26/8/2017 61 46 14
Thu 10/8/2017 54 45 9
Mon 24/7/2017 55 44 12
Sun 16/7/2017 54 44 10
Sun 18/6/2017 55 49 6
Sun 11/6/2017 57 49 8

Timaru airshed - Last exceedance on 4/10/2023

This monitoring site is located on Anzac Square near Rose Street, Timaru, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Wed 4/10/2023 55 18 37
Thu 24/8/2023 58 35 23
Mon 31/7/2023 63 35 28
Wed 5/7/2023 53 32 21
Thu 29/6/2023 60 38 22
Wed 31/5/2023 52 30 22
Sun 17/7/2022 53 44 9
Fri 24/6/2022 62 49 13
Wed 22/6/2022 54 37 17
Sun 22/8/2021 63 49 14
Thu 12/8/2021 55 28 28
Wed 21/7/2021 59 45 15
Tue 20/7/2021 53 42 11
Wed 14/7/2021 52 35 17
Mon 12/7/2021 61 42 19
Mon 5/7/2021 62 47 15
Sun 4/7/2021 55 47 9
Sat 3/7/2021 58 49 9
Thu 1/7/2021 64 41 22
Fri 4/6/2021 56 41 15
Thu 27/5/2021 61 43 18
Sat 8/5/2021 52 31 20
Wed 19/8/2020 52 23 29
Sun 2/8/2020 75 53 22
Sat 1/8/2020 64 43 21
Thu 30/7/2020 59 38 21
Wed 29/7/2020 54 37 16
Tue 28/7/2020 56 39 16
Fri 10/7/2020 51 37 14
Sat 4/7/2020 53 42 11
Mon 15/6/2020 58 39 19
Thu 21/5/2020 52 30 23
Wed 27/11/2019 52 10 41
Tue 26/11/2019 51 12 38
Thu 15/8/2019 64 34 30
Thu 8/8/2019 69 41 29
Wed 7/8/2019 54 33 20
Mon 29/7/2019 56 37 19
Sun 28/7/2019 77 51 26
Sat 27/7/2019 61 41 20
Tue 2/7/2019 63 40 23
Mon 1/7/2019 72 44 29
Sun 30/6/2019 53 43 10
Fri 28/6/2019 66 44 22
Mon 13/8/2018 56 33 24
Wed 1/8/2018 56 21 35
Fri 20/7/2018 61 46 15
Thu 19/7/2018 69 50 19
Wed 18/7/2018 60 40 21
Fri 6/7/2018 77 57 21
Wed 4/7/2018 53 37 15
Thu 21/6/2018 62 44 18
Sat 26/8/2017 71 40 30
Fri 25/8/2017 60 31 29
Mon 31/7/2017 53 30 22
Sun 30/7/2017 61 50 11
Wed 26/7/2017 63 35 28
Mon 24/7/2017 60 39 21
Sun 16/7/2017 52 46 6
Mon 10/7/2017 64 51 13
Mon 3/7/2017 53 35 18
Mon 26/6/2017 57 34 22
Sat 24/6/2017 60 43 17
Wed 21/6/2017 70 55 15
Tue 20/6/2017 59 48 10
Sat 17/6/2017 60 46 14
Mon 22/5/2017 55 37 19
Mon 15/5/2017 52 39 13
Thu 27/4/2017 57 26 31

Washdyke airshed - Last exceedance on 16/5/2024

This monitoring site was located on Washdyke Flat Road before March 2019 and is now located on Meadows Road, Washdyke, Timaru. Both of these sites are in an industrial area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Thu 16/5/2024 86 16 70
Tue 30/4/2024 63 15 48
Wed 24/4/2024 56 12 44
Fri 19/4/2024 63 12 51
Wed 10/4/2024 53 11 42
Tue 9/4/2024 52 9 43
Wed 3/4/2024 55 12 43
Fri 22/3/2024 54 13 41
Mon 19/2/2024 55 11 44
Thu 15/2/2024 55 9 46
Thu 11/1/2024 56 11 45
Thu 23/11/2023 98 16 82
Fri 6/10/2023 66 11 55
Wed 4/10/2023 91 22 69
Thu 21/9/2023 62 12 50
Fri 15/9/2023 86 15 71
Thu 14/9/2023 69 10 59
Tues 12/9/2023 51 9 42
Mon 11/9/2023 83 13 70
Wed 6/9/2023 54 12 42
Fri 1/9/2023 66 14 52
Thu 31/8/2023 55 12 43
Sat 26/8/2023 56 23 33
Thu 24/8/2023 63 17 46
Mon 21/8/2023 51 16 35
Mon 31/7/2023 72 18 54
Wed 19/7/2023 53 11 42
Tue 18/7/2023 71 14 57
Mon 17/7/2023 58 14 44
Thu 13/7/2023 54 17 37
Wed 5/7/2023 59 17 42
Tue 4/7/2023 74 17 57
Fri 30/6/2023 54 14 40
Thu 29/6/2023 60 17 43
Sat 24/6/2023 81 22 59
Wed 31/5/2023 60 13 47
Wed 3/5/2023 58 10 48
Tues 2/5/2023 66 17 49
Tues 18/4/2023 51 14 37
Mon 17/4/2023 56 14 42
Wed 8/3/2023 51 11 40
Tues 21/2/2023 100 18 82
Wed 8/2/2023 51 11 40
Tue 7/2/2023 63 13 50
Fri 27/1/2023 53 11 42
Fri 20/1/2023 62 16 46
Wed 14/12/2022 61 14 47
Fri 9/12/2022 56 13 43
Thu 20/10/2022 54 11 43
Wed 19/10/2022 58 10 48
Mon 10/10/2022 62 9 53
Thu 29/9/2022 79 15 64
Tue 20/9/2022 60 10 50
Mon 5/9/2022 67 12 55
Thur 1/9/2022 67 16 51
Tue 16/8/2022 56 19 37
Fri 5/8/2022 81 17 64
Thu 7/7/2022 55 19 36
Wed 15/6/2022 65 16 49
Tue 31/5/2022 68 18 50
Wed 25/5/2022 55 14 41
Mon 02/5/2022 58 15 42
Wed 20/4/2022 57 18 40
Fri 11/3/2022 73 15 57
Sat 19/2/2022 71 12 59
Fri 18/2/2022 53 10 43
Wed 22/12/2021 88 15 72
Mon 20/12/2021 58 8 50
Fri 26/11/2021 53 9 44
Fri 12/11/2021 63 12 50
Fri 24/09/2021 70 15 55
Mon 6/9/2021 51 12 39
Fri 3/9/2021 51 14 37
Thu 12/8/2021 84 19 65
Wed 11/8/2021 57 16 42
Thu 5/8/2021 52 17 36
Wed 28/7/2021 67 20 47
Mon 26/7/2021 59 18 41
Wed 21/7/2021 62 21 41
Wed 14/7/2021 58 19 39
Tue 6/7/2021 65 14 51
Mon 5/7/2021 75 24 51
Wed 30/6/2021 63 14 48
Fri 25/6/2021 59 16 42
Thu 27/5/2021 85 28 57
Wed 26/5/2021 54 17 37
Fri 7/5/2021 52 11 40
Tue 4/5/2021 70 16 54
Thu 29/4/2021 54 11 43
Fri 23/4/2021 60 12 48
Mon 15/3/2021 57 10 47
Wed 24/2/2021 65 8 57
Tue 9/2/2021 62 14 48
Wed 27/1/2021 70 12 58
Mon 16/11/2020 68 7 61
Thu 5/11/2020 72 9 63
Wed 14/10/2020 66 6 59
Mon 5/10/2020 57 9 47
Wed 23/9/2020 66 8 57
Thu 17/9/2020 53 4 50
Wed 19/8/2020 73 16 57
Thu 13/8/2020 62 8 54
Sun 2/8/2020 51 19 32
Fri 31/7/2020 52 22 31
Wed 17/6/2020 66 13 53
Thu 11/6/2020 57 16 41
Thu 14/5/2020 55 24 31
Fri 1/5/2020 53 11 42
Thu 19/3/2020 53 10 42
Mon 16/3/2020 71 11 60
Tue 3/3/2020 55 12 42
Thu 27/2/2020 89 15 74
Fri 21/2/2020 51 10 41
Fri 31/1/2020 63 12 51
Thu 30/1/2020 124 12 112
Sat 25/1/2020 77 12 65
Wed 4/12/2019 71 6 65
Tue 3/12/2019 60 6 54
Wed 27/11/2019 63 11 52
Tue 5/11/2019 56 12 44
Tue 8/10/2019 58 15 43
Thu 12/9/2019 58 9 49
Thu 15/8/2019 75 14 61
Thu 8/8/2019 59 14 45
Tue 2/7/2019 63 20 43
Mon 1/7/2019 66 18 48
Fri 28/6/2019 52 14 38
Wed 10/4/2019 86 12 75
Tue 26/3/2019 74 11 63
Mon 25/3/2019 78 15 63
Tue 20/3/2018 61 18 43
Thu 27/4/2017 58 11 47

Waimate airshed - Last exceedance on 2/7/2019

This monitoring site is located on Kennedy Crescent, Waimate, which is in a residential area.
Date of exceedance PM10 (µg/m3) PM2.5 (µg/m3) PM2.5-10 (µg/m3)
Tue 2/07/2019 55 45 10
Thu 20/07/2017 52 39 13
Wed 21/06/2017 62 53 9