The Air We Breathe | HT Pollution Dashboard

Delhi and five neighbouring cities: Noida, Ghaziabad, Gurugram, Faridabad and Greater Noida.

Delhi in the past 24 hours

355 AQI

Up 25 since this time yesterday

Very Poor

CPCB's average of Delhi's stations for 10pm, November 3

Delhi's worst official figure since January 20 (287 days)

Official AQI bulletin figure, November 3: 350Very Poor or worse for 2 days

Main pollutant: Fine particles; PM2.5 · leads at 51 of 57 stations
Wind: Calm; still air; Safdarjung, 10.30pm

Farm fires: Farm fires spotted by NASA's satellite in Punjab and Haryana: October 27, 65; October 28, 138; October 29, 157; October 30, 55; October 31, 106; November 1, 171; November 2, 167.; Punjab and Haryana · NASA, an undercount

Delhi's official daily AQI since October 1:2 Very Poor6 Poor23 Moderate3 Satisfactory

Your location and searches stay on your device. Your phone then asks us for the nearest station's figures.

Delhi's main pollutants in the past 24 hours

PM2.5 (fine particles) has been the main pollutant at most of Delhi's stations over the past 24 hours, PM10 (coarse particles) at the rest.

Each pollutant's score at Delhi's 57 reporting stations, on CPCB's 0 to 500 scale. The line runs from the lowest station to the highest; the dot is the middle station.

Pollutant	Lowest to highest station	Middle station
PM_2.5fine particles	Middle station 361, Very Poor; lowest 82, highest 450.	361Very Poor
PM₁₀coarse particles	Middle station 304, Very Poor; lowest 152, highest 445.	304Very Poor
COcarbon monoxide	Middle station 79, Satisfactory; lowest 16, highest 122.	79Satisfactory
NO₂nitrogen dioxide	Middle station 57, Satisfactory; lowest 1, highest 145.	57Satisfactory
O₃ozone	Middle station 25, Good; lowest 5, highest 133.	25Good
SO₂sulphur dioxide	Middle station 14, Good; lowest 2, highest 71.	14Good
NH₃ammonia	Middle station 7, Good; lowest 0, highest 23.	7Good
	0100200300400500

Each score is CPCB's running average: over the past 24 hours for PM2.5, PM10, nitrogen dioxide, sulphur dioxide and ammonia, over the past 8 hours for ozone and carbon monoxide.

The mix differs from station to station.

Delhi: hour by hour, the past day

Show the numbers

Time	AQI	Category
10pm, November 3	355	Very Poor
9pm, November 3	355	Very Poor
8pm, November 3	354	Very Poor
7pm, November 3	353	Very Poor
6pm, November 3	352	Very Poor
5pm, November 3	351	Very Poor
4pm, November 3	350	Very Poor
3pm, November 3	348	Very Poor
2pm, November 3	346	Very Poor
1pm, November 3	343	Very Poor
12pm, November 3	340	Very Poor
11am, November 3	337	Very Poor
10am, November 3	334	Very Poor
9am, November 3	332	Very Poor
8am, November 3	330	Very Poor
7am, November 3	331	Very Poor
6am, November 3	331	Very Poor
5am, November 3	332	Very Poor
4am, November 3	332	Very Poor
3am, November 3	331	Very Poor
2am, November 3	331	Very Poor
1am, November 3	330	Very Poor
midnight, November 3	330	Very Poor
11pm, November 2	330	Very Poor
10pm, November 2	330	Very Poor

About these figures

At 10pm, PM2.5 (fine particles) led at 51 and PM10 (coarse particles) led at 6 of Delhi's 57 reporting stations.
This hourly figure averages the city's monitoring stations. CPCB's official figure for the day is its 4pm bulletin, below.
Each station is led by whichever pollutant scores highest on CPCB's 0 to 500 scale. Ozone forms from other pollutants in sunlight, so it can lead on sunny afternoons.
Like each station's number, it is an average of recent hours, so it changes slowly.

Source: CPCB. Analysis: HT Pollution Dashboard.

Today's official AQI bulletin figure

350Very Poor

Up 26 from 324 the day before.

Highest since January 20

On January 20 it was 378.

Show the numbers

Date	AQI	Category
November 3	350	Very Poor
November 2	324	Very Poor
November 1	261	Poor
October 31	117	Moderate
October 30	60	Satisfactory
October 29	222	Poor
October 28	229	Poor
October 27	197	Moderate
October 26	174	Moderate
October 25	153	Moderate
October 24	191	Moderate
October 23	230	Poor
October 22	223	Poor
October 21	245	Poor
October 20	179	Moderate
October 19	139	Moderate
October 18	187	Moderate
October 17	159	Moderate
October 16	90	Satisfactory
October 15	149	Moderate
October 14	181	Moderate
October 13	158	Moderate
October 12	83	Satisfactory
October 11	111	Moderate
October 10	122	Moderate
October 9	176	Moderate
October 8	162	Moderate
October 7	136	Moderate
October 6	179	Moderate
October 5	184	Moderate
October 4	187	Moderate
October 3	171	Moderate
October 2	174	Moderate
October 1	166	Moderate
September 30	129	Moderate
September 29	71	Satisfactory
September 28	56	Satisfactory
September 27	53	Satisfactory
September 26	72	Satisfactory
September 25	78	Satisfactory
September 24	145	Moderate
September 23	154	Moderate
September 22	178	Moderate
September 21	169	Moderate
September 20	160	Moderate
September 19	118	Moderate
September 18	88	Satisfactory
September 17	106	Moderate
September 16	94	Satisfactory
September 15	98	Satisfactory
September 14	79	Satisfactory
September 13	84	Satisfactory
September 12	70	Satisfactory
September 11	127	Moderate
September 10	134	Moderate
September 9	128	Moderate
September 8	113	Moderate
September 7	85	Satisfactory
September 6	55	Satisfactory
September 5	59	Satisfactory
September 4	71	Satisfactory
September 3	74	Satisfactory
September 2	85	Satisfactory
September 1	113	Moderate
August 31	116	Moderate
August 30	129	Moderate
August 29	130	Moderate
August 28	128	Moderate
August 27	129	Moderate
August 26	94	Satisfactory
August 25	101	Moderate
August 24	111	Moderate
August 23	96	Satisfactory
August 22	81	Satisfactory
August 21	117	Moderate
August 20	110	Moderate
August 19	108	Moderate
August 18	100	Satisfactory
August 17	111	Moderate
August 16	92	Satisfactory
August 15	93	Satisfactory
August 14	98	Satisfactory
August 13	105	Moderate
August 12	92	Satisfactory
August 11	78	Satisfactory
August 10	89	Satisfactory
August 9	87	Satisfactory
August 8	63	Satisfactory
August 7	63	Satisfactory
August 6	74	Satisfactory
August 5	69	Satisfactory
August 4	64	Satisfactory
August 3	76	Satisfactory
August 2	78	Satisfactory
August 1	80	Satisfactory
July 31	77	Satisfactory
July 30	107	Moderate
July 29	96	Satisfactory
July 28	66	Satisfactory
July 27	101	Moderate
July 26	80	Satisfactory
July 25	73	Satisfactory
July 24	70	Satisfactory
July 23	73	Satisfactory
July 22	64	Satisfactory
July 21	69	Satisfactory
July 20	127	Moderate
July 19	171	Moderate
July 18	174	Moderate
July 17	177	Moderate
July 16	176	Moderate
July 15	136	Moderate
July 14	172	Moderate
July 13	246	Poor
July 12	261	Poor
July 11	140	Moderate
July 10	65	Satisfactory
July 9	48	Good
July 8	59	Satisfactory
July 7	113	Moderate
July 6	94	Satisfactory
July 5	161	Moderate
July 4	123	Moderate
July 3	105	Moderate
July 2	96	Satisfactory
July 1	132	Moderate
June 30	177	Moderate
June 29	151	Moderate
June 28	152	Moderate
June 27	130	Moderate
June 26	127	Moderate
June 25	130	Moderate
June 24	127	Moderate
June 23	142	Moderate
June 22	228	Poor
June 21	127	Moderate
June 20	132	Moderate
June 19	142	Moderate
June 18	157	Moderate
June 17	92	Satisfactory
June 16	116	Moderate
June 15	151	Moderate
June 14	151	Moderate
June 13	96	Satisfactory
June 12	73	Satisfactory
June 11	167	Moderate
June 10	169	Moderate
June 9	164	Moderate
June 8	151	Moderate
June 7	144	Moderate
June 6	176	Moderate
June 5	131	Moderate
June 4	164	Moderate
June 3	143	Moderate
June 2	106	Moderate
June 1	105	Moderate
May 31	98	Satisfactory
May 30	85	Satisfactory
May 29	123	Moderate
May 28	207	Poor
May 27	190	Moderate
May 26	252	Poor
May 25	254	Poor
May 24	205	Poor
May 23	195	Moderate
May 22	183	Moderate
May 21	209	Poor
May 20	168	Moderate
May 19	208	Poor
May 18	173	Moderate
May 17	174	Moderate
May 16	176	Moderate
May 15	152	Moderate
May 14	154	Moderate
May 13	147	Moderate
May 12	170	Moderate
May 11	131	Moderate
May 10	127	Moderate
May 9	116	Moderate
May 8	100	Satisfactory
May 7	125	Moderate
May 6	121	Moderate
May 5	86	Satisfactory
May 4	88	Satisfactory
May 3	175	Moderate
May 2	144	Moderate
May 1	120	Moderate
April 30	148	Moderate
April 29	183	Moderate
April 28	239	Poor
April 27	197	Moderate
April 26	222	Poor
April 25	243	Poor
April 24	226	Poor
April 23	176	Moderate
April 22	216	Poor
April 21	177	Moderate
April 20	181	Moderate
April 19	258	Poor
April 18	none
April 17	263	Poor
April 16	226	Poor
April 15	204	Poor
April 14	167	Moderate
April 13	149	Moderate
April 12	163	Moderate
April 11	123	Moderate
April 10	151	Moderate
April 9	101	Moderate
April 8	93	Satisfactory
April 7	114	Moderate
April 6	135	Moderate
April 5	134	Moderate
April 4	137	Moderate
April 3	266	Poor
April 2	194	Moderate
April 1	113	Moderate
March 31	171	Moderate
March 30	180	Moderate
March 29	198	Moderate
March 28	154	Moderate
March 27	144	Moderate
March 26	185	Moderate
March 25	183	Moderate
March 24	192	Moderate
March 23	132	Moderate
March 22	153	Moderate
March 21	119	Moderate
March 20	93	Satisfactory
March 19	137	Moderate
March 18	232	Poor
March 17	189	Moderate
March 16	119	Moderate
March 15	175	Moderate
March 14	153	Moderate
March 13	189	Moderate
March 12	213	Poor
March 11	244	Poor
March 10	265	Poor
March 9	209	Poor
March 8	247	Poor
March 7	246	Poor
March 6	172	Moderate
March 5	142	Moderate
March 4	161	Moderate
March 3	216	Poor
March 2	193	Moderate
March 1	191	Moderate
February 28	248	Poor
February 27	200	Moderate
February 26	200	Moderate
February 25	228	Poor
February 24	239	Poor
February 23	228	Poor
February 22	229	Poor
February 21	213	Poor
February 20	210	Poor
February 19	208	Poor
February 18	214	Poor
February 17	249	Poor
February 16	261	Poor
February 15	216	Poor
February 14	230	Poor
February 13	197	Moderate
February 12	164	Moderate
February 11	305	Very Poor
February 10	271	Poor
February 9	249	Poor
February 8	189	Moderate
February 7	227	Poor
February 6	220	Poor
February 5	241	Poor
February 4	339	Very Poor
February 3	272	Poor
February 2	210	Poor
February 1	265	Poor
January 31	315	Very Poor
January 30	253	Poor
January 29	226	Poor
January 28	255	Poor
January 27	336	Very Poor
January 26	241	Poor
January 25	153	Moderate
January 24	192	Moderate
January 23	282	Poor
January 22	322	Very Poor
January 21	330	Very Poor
January 20	378	Very Poor

Across India

Delhi's figure was the 3rd worst of the 272 cities in CPCB's bulletin for November 3.

The worst figures on November 3

1	Gajraula	399
2	Baghpat, Uttar Pradesh	360
3	Delhi, Delhi	350
4	Bahadurgarh, Haryana	324
5	Panchgaon	320
6	Ballabgarh, Haryana	319
7	Khora	318
8	Manesar, Haryana	309
9	Gurugram, Haryana	305
9	Modinagar	305

A city's figure can rest on one station or on dozens, so its place is a rough guide.

About these figures

CPCB publishes one figure a day for each city, covering the 24 hours to 4pm on November 3. This one came out at 4.07pm. Read CPCB's bulletin (PDF)
Based on 57 of Delhi's 59 stations.
Main pollutant: PM2.5 (fine particles).
CPCB's six categories are Good (up to 50), Satisfactory (to 100), Moderate (to 200), Poor (to 300), Very Poor (to 400) and Severe (to 500).
The daily figure averages the city's stations over the 24 hours to 4pm. The hourly figure above can differ from it.

Source: CPCB daily AQI bulletin. Analysis: HT Pollution Dashboard.

Stations across Delhi-NCR

Each dot is a monitoring station, coloured by CPCB's reading for 10pm, November 3.

Stations in Delhi, highest first

Show the numbers

Station	AQI	Category
Jahangirpuri, Delhi	450	Severe
Punjabi Bagh, Delhi	440	Severe
Rohini, Delhi	436	Severe
Mundka, Delhi	435	Severe
DTU, Delhi	431	Severe
Alipur, Delhi	422	Severe
Vivek Vihar, Delhi	417	Severe
IIT Delhi, Delhi	416	Severe
Narela, Delhi	415	Severe
Bawana, Delhi	409	Severe
Sector - 62, Noida	405	Severe
R K Puram, Delhi	404	Severe
Pusa, Delhi	400	Very Poor
North Campus, DU, Delhi	398	Very Poor
ITO, Delhi	393	Very Poor
Patparganj, Delhi	393	Very Poor
NIH Narela, Delhi	391	Very Poor
Mandir Marg, Delhi	389	Very Poor
Sirifort, Delhi	389	Very Poor
Dwarka-Sector 8, Delhi	383	Very Poor
Okhla Phase-2, Delhi	383	Very Poor
Jawaharlal Nehru Stadium, Delhi	381	Very Poor
Burari Crossing, Delhi	380	Very Poor
Sector-39, Noida	377	Very Poor
Pusa, Delhi	376	Very Poor
Dr. Karni Singh Shooting Range, Delhi	375	Very Poor
Talkatora Garden, Delhi	373	Very Poor
Major Dhyan Chand National Stadium, Delhi	372	Very Poor
CRRI Mathura Road, Delhi	369	Very Poor
Commonwealth Sports Complex, Delhi	367	Very Poor
JNU, Delhi	363	Very Poor
Chandni Chowk, Delhi	361	Very Poor
Wazirpur, Delhi	361	Very Poor
NSUT Jaffarpur, Delhi	360	Very Poor
Burari, Delhi	356	Very Poor
Najafgarh, Delhi	353	Very Poor
Teri Gram, Gurugram	350	Very Poor
Ashok Vihar, Delhi	347	Very Poor
Aya Nagar, Delhi	345	Very Poor
NISE Gwal Pahari, Gurugram	342	Very Poor
Sector-150, Noida	342	Very Poor
Shadipur, Delhi	339	Very Poor
Ghoga, Delhi	330	Very Poor
IGI Airport (T3), Delhi	329	Very Poor
Sector-51, Gurugram	329	Very Poor
NSIT Dwarka, Delhi	327	Very Poor
Jharoda Kalan, Delhi	320	Very Poor
Vasundhara Enclave, Delhi	319	Very Poor
Badarpur, Delhi	317	Very Poor
Nehru Nagar, Delhi	317	Very Poor
Wave City, Ghaziabad	308	Very Poor
IHBAS, Dilshad Garden, Delhi	307	Very Poor
Karala, Delhi	305	Very Poor
Uttam Nagar, Delhi	303	Very Poor
Loni, Ghaziabad	302	Very Poor
Tikri Kalan, Delhi	302	Very Poor
Ghummanhera, Delhi	288	Poor
Anand Vihar, Delhi	284	Poor
Sri Aurobindo Marg, Delhi	281	Poor
Cantonment Area, Delhi	275	Poor
Maidan Garhi, Delhi	275	Poor
Sanjay Nagar, Ghaziabad	264	Poor
Chhawla, Delhi	262	Poor
IMD Lodhi Road, Delhi	262	Poor
Vikas Sadan, Gurugram	257	Poor
IGNOU_Maidan Garhi, Delhi	237	Poor
Lodhi Road, Delhi	223	Poor
Knowledge Park - V, Greater Noida	198	Moderate
Indirapuram, Ghaziabad	194	Moderate
Shiv Nadar University, Greater Noida	194	Moderate
Sector-116, Noida	189	Moderate
New Industrial Town, Faridabad	186	Moderate
Sector - 125, Noida	180	Moderate
Vasundhara, Ghaziabad	176	Moderate
Ved Vihar-Loni, Ghaziabad	176	Moderate
Govindpuram, Ghaziabad	172	Moderate
New Tehsil-Loni, Ghaziabad	166	Moderate
Knowledge Park - III, Greater Noida	147	Moderate
Sector-1, Noida	147	Moderate
Sector 30, Faridabad	94	Satisfactory
Sector 11, Faridabad	81	Satisfactory
Nangloi, Delhi	No figure this hour
Sector-110, Noida	No figure this hour
Sonia Vihar, Delhi	No figure this hour

About these figures

A hollow dot is a station with no reading for this hour.
Your position, if you share it, is used only in your browser to place the ring. It is not sent to HT.

Source: CPCB. Analysis: HT Pollution Dashboard. District and state outlines: DataMeet (CC BY 4.0), simplified.

The weather and air quality

Delhi's air got worse than the day before: CPCB's official figure rose 26, from 324 on November 2 to 350 on November 3, Very Poor. It was the fourth day in a row the official figure rose: up 290 since October 30, from Satisfactory to Very Poor.

Also at play

The air was calm overnight, but at dawn the lid of warm air sat higher than the morning before.

From the HT Pollution Dashboard's evening edition, 7.21pm.

The wind now

Still air: pollution stays close to where it is made.

Safdarjung airfield, 10.30pm

Since the 4pm bulletin

No rain at Safdarjung since 4pm today. The wind has averaged 1 km/h, mostly from the west-south-west.

Drier air moved in from about 8.30pm, the dew point at Safdarjung airfield falling from 23°C to as low as 18°C.

More on the inversion effect and how it influences air quality

The air across Delhi-NCR has a daily rhythm. A crucial part of it is known as the atmospheric inversion, when a lid of air impedes how much wind and emissions move close to the ground. At night a lid of warm air settles low over the region and holds the night's smoke near the ground. After sunrise the sun warms the ground, the lid lifts and pollution mixes upwards. By late afternoon the air has had all the room it will get that day; after sunset the lid forms again.

That is why HT reads IMD’s 4.30pm weather balloon: it shows the most room the day gave the city’s pollution to spread and thin out. If the lid lasts all day, pollution tends to stay high.

Normally the air is warmest at the ground and cools with height, so air warmed by the ground rises and carries pollution upwards. On clear, calm nights the ground cools fast and chills the air just above it, while the air higher up stays warmer. This upside-down layering is called an inversion. It works like a lid, because cold air below cannot rise through the warm layer, and the night's smoke and dust stay near the ground. The sun breaks the lid by warming the ground again. In October and November the afternoon sun almost always breaks the lid. Last winter it was still there at 4.30pm on 2 of 30 October afternoons and 1 of 30 in November.

How much the weather helps depends on both: how high the air can spread, and how fast the wind moves through it. The wind measured 10 metres above the ground at Safdarjung shows whether the air people breathe is moving. Calm hours let pollution build up near the ground, even when the air higher up has room to spread. The balloon readings show how much room the weather gave the air to clear. Whether it did clear also depends on the wind near the ground, so the two are read together.

Rain washes particles out of the air. A little rain does not always clean the air. Light drizzle can leave the air damp and still, and in past winters scant rain in Delhi has at times been followed by worse air, not better.

CPCB's figures average recent hours, so a change in the weather can take hours to show in them.

About these figures

Today, 4.30am: a lid of warm air about 300 metres up, about 6°C warmer than the ground; the wind beneath it 11 km/h from the north-north-west.
This afternoon: the air could spread about 600 metres up, with the wind through it averaging 20 km/h; the usual for early November is 1,300 metres and 13 km/h.
This shows how much the weather let Delhi's air clear. It does not measure pollution or show where it came from.
A weather balloon that IMD sends up at Safdarjung at 4.30pm measures how high pollution can spread. The 4.30am balloon measures the lid.
The same balloon measures the wind through that air.
The usual is the middle value for the same half-month over the six winters from 2019-20 to 2024-25, from the same balloon.
One balloon at Safdarjung stands for all of Delhi.
CPCB's daily figure covers the 24 hours to 4pm, so a change in the weather can show here before it shows in that figure.

Source: IMD weather balloon and observatory, Safdarjung. Analysis: HT Pollution Dashboard.

Delhi: this season against past seasons

Delhi's official figure averaged 223 over the week to November 3, the cleanest of the 12 years for that week, going back to 2015.

The official daily figure, October 1 to November 24

Dussehra (October 20) and Diwali (November 8) fall in this period.

Show the numbers

Date	This season	Past middle
October 1	166	151
October 2	174	174
October 3	171	155
October 4	187	183
October 5	184	177
October 6	179	178
October 7	136	181
October 8	162	167
October 9	176	175
October 10	122	180
October 11	111	202
October 12	83	220
October 13	158	236
October 14	181	218
October 15	149	246
October 16	90	262
October 17	159	284
October 18	187	268
October 19	139	246
October 20	179	262
October 21	245	264
October 22	223	284
October 23	230	292
October 24	191	309
October 25	153	292
October 26	174	287
October 27	197	329
October 28	229	304
October 29	222	338
October 30	60	363
October 31	117	359
November 1	261	364
November 2	324	370
November 3	350	373
November 4		381
November 5		381
November 6		352
November 7		395
November 8		390
November 9		404
November 10		362
November 11		360
November 12		387
November 13		404
November 14		377
November 15		372
November 16		357
November 17		310
November 18		319
November 19		330
November 20		361
November 21		366
November 22		332
November 23		321
November 24		348
November 25		322
November 26		336
November 27		328
November 28		316
November 29		331
November 30		352
December 1		356
December 2		352
December 3		341
December 4		337
December 5		347
December 6		330
December 7		320
December 8		324
December 9		321
December 10		350
December 11		317
December 12		349
December 13		281
December 14		249
December 15		272
December 16		282
December 17		329
December 18		330
December 19		347
December 20		359
December 21		370
December 22		373
December 23		412
December 24		383
December 25		357
December 26		337
December 27		363
December 28		358
December 29		364
December 30		388
December 31		373
January 1		386
January 2		384
January 3		371
January 4		366
January 5		339
January 6		335
January 7		296
January 8		289
January 9		337
January 10		292
January 11		308
January 12		331
January 13		357
January 14		348
January 15		317
January 16		302
January 17		327
January 18		344
January 19		348
January 20		323
January 21		330
January 22		334
January 23		308
January 24		265
January 25		250
January 26		298
January 27		285
January 28		267
January 29		307
January 30		294
January 31		338

About these figures

Past seasons: 2015-16 to 2025-26 (11). Diwali fell between October 19 and November 14 in those years, so its spike sits on different days in each season.
Each season here runs from October 1 to January 31. Days without a bulletin are gaps, never filled.
The comparison uses the average of the latest seven bulletins against the same seven days in each earlier year, so one unusual day does not decide it.
Some cities joined CPCB's bulletin later than others, so their comparison covers fewer years.

Source: CPCB daily AQI bulletin. Analysis: HT Pollution Dashboard.

Farm fires in Punjab and Haryana

1,561fires spotted by NASA's satellite, October 1 to November 2

NASA's satellite passes at about 1.30pm, and most burning now happens later in the day, so its count is far below the real number.

From the HT Pollution Dashboard's evening edition, 7.21pm.

Fires spotted each day

Show the numbers

Date	Fires spotted
October 1	11
October 2	28
October 3	7
October 4	10
October 5	8
October 6	8
October 7	25
October 8	10
October 9	8
October 10	14
October 11	0
October 12	13
October 13	0
October 14	15
October 15	3
October 16	7
October 17	48
October 18	112
October 19	48
October 20	22
October 21	40
October 22	58
October 23	50
October 24	63
October 25	25
October 26	69
October 27	65
October 28	138
October 29	157
October 30	55
October 31	106
November 1	171
November 2	167

About these figures

A lower count than last season does not mean fewer fires. Since 2021, most burning happens after the satellite passes, so its count cannot show whether burning rose or fell.
The count leaves out fixed hot spots such as factories, and detections the satellite is unsure of.
The count comes from the VIIRS instrument, which sees the ground in squares about 375 metres across. NASA's older MODIS instrument sees squares about 1 km across, so it can count nearby fires as one; counts from the two are not comparable.

Source: NASA FIRMS, VIIRS instrument on the Suomi NPP satellite. Analysis: HT Pollution Dashboard.