Burned area
satellite only6,992ha
Perimeter published by NBAC (NRCan).
- Source
- NBAC (NRCan)
- Date
- 7 Jul 2023 – 6 Aug 2023
+− cross-check
No official record is matched to this page to compare it with.
CA · Canada · –
Bulkley-Nechako B fire, 7 July 2023 Bulkley-Nechako B
Out · last detection 6 Aug 2023, 20:20 UTC
The fire started on 7 July 2023 in Bulkley-Nechako B, Canada, and satellites saw it burning for 31 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 6,992 hectares from satellite imagery, spread across a single census subdivision.
It is the 118th largest in British Columbia since 2016 (of 343 with a page). Number 215 in Canada in 2023, of 489.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-25matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only31days
7 Jul 2023 to 6 Aug 2023: first and last day with fire on the page.
- Source
- NBAC (NRCan) · NASA FIRMS · VIIRS
- Date
- last detection: 6 Aug 2023, 20:20 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only7 Jul 2023
First day with fire seen by the satellites or the perimeter.
- Source
- NBAC (NRCan) · NASA FIRMS · VIIRS
- Date
- 7 Jul 2023
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only2,086
VIIRS detections at 375 m. Most intense hotspot: 762 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP + NOAA-20)
- Date
- 7 Jul 2023 – 6 Aug 2023
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only15,950MW
Total radiative power on 11 July 2023; hotspots that day: 587.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 11 Jul 2023
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model20.5FWI · moderate
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 5.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 7 Jul 2023, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model26.3°C · 30% RH
High of 26.3 °C and minimum humidity of 30% on 8 July 2023; gusts of 48 km/h on 17 July 2023.
- Source
- weather model at the fire’s grid cell
- Date
- 7 Jul 2023 – 6 Aug 2023
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
logLast day with fire: 5 August 2023 → 6 August 2023.
-
· reconstructed GHSLPopulation and built-up area computed
What was saved on 25 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 6,992 ha
- Dates
- 7 Jul 2023 – 6 Aug 2023
- Name
- Bulkley-Nechako B
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/bulkley-nechako-b-2023-07?v=2026-10-25A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire bulkley-nechako-b-2023-07.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2023-07-07 | 0 | 0 | 25.5 | 11.8 | 27 | 7.7 | 26.6 | 1.7 | 20.5 | moderado | 1 |
| 2023-07-08 | 20 | 424 | 26.3 | 12.3 | 30 | 8.7 | 24.5 | 0.8 | 11.1 | bajo | 1 |
| 2023-07-09 | 87 | 2,086 | 24.2 | 10.6 | 40 | 12.6 | 27.7 | 0.5 | 12.5 | moderado | 1 |
| 2023-07-10 | 172 | 2,941 | 20.6 | 10.3 | 44 | 14.8 | 38.2 | 0.8 | 15.6 | moderado | 1 |
| 2023-07-11 | 587 | 15,950 | 21.5 | 8 | 27 | 12.8 | 33.8 | 0 | 16.2 | moderado | 1 |
| 2023-07-12 | 619 | 4,125 | 19.1 | 5.8 | 33 | 8 | 24.1 | 0 | 17.5 | moderado | 1 |
| 2023-07-13 | 305 | 1,271 | 19.3 | 8 | 37 | 7.4 | 28.4 | 0 | 19.1 | moderado | 1 |
| 2023-07-14 | 109 | 285 | 17.8 | 7.7 | 52 | 8 | 24.5 | 0.7 | 18 | moderado | 1 |
| 2023-07-15 | 69 | 225 | 20.2 | 9.3 | 38 | 12.7 | 29.2 | 0.2 | 21 | moderado | 1 |
| 2023-07-16 | 46 | 80 | 18.2 | 8.3 | 53 | 8.7 | 20.9 | 4.8 | 9.3 | bajo | 1 |
| 2023-07-17 | 0 | 0 | 16.6 | 7.7 | 43 | 18.4 | 47.9 | 0 | 5.6 | bajo | 1 |
| 2023-07-18 | 5 | 30 | 16.4 | 7.7 | 52 | 14.8 | 38.9 | 0 | 10.2 | bajo | 1 |
| 2023-07-19 | 1 | 7 | 23.1 | 6.4 | 33 | 6.3 | 16.2 | 0.2 | 11.4 | moderado | 1 |
| 2023-07-20 | 38 | 342 | 24.5 | 10.9 | 36 | 11.2 | 28.1 | 2.4 | 21.8 | alto | 1 |
| 2023-07-21 | 25 | 26 | 17.5 | 10.9 | 63 | 12.6 | 28.8 | 5.4 | 0.8 | muy_bajo | 1 |
| 2023-07-22 | 1 | 1 | 17.8 | 7.4 | 52 | 14.5 | 33.5 | 4.5 | 1 | muy_bajo | 1 |
| 2023-07-23 | 0 | 0 | 17.1 | 5.9 | 45 | 5.9 | 21.6 | 1.9 | 0.5 | muy_bajo | 1 |
| 2023-07-24 | 0 | 0 | 16.9 | 9 | 58 | 6.8 | 18.7 | 11.2 | 0.3 | muy_bajo | 1 |
| 2023-07-25 | 0 | 0 | 10.5 | 7.2 | 86 | 15.3 | 39.6 | 29.5 | 0 | muy_bajo | 1 |
| 2023-07-26 | 0 | 0 | 16.4 | 8.3 | 53 | 16.8 | 46.8 | 0 | 0.3 | muy_bajo | 1 |
| 2023-07-27 | 0 | 0 | 14.1 | 9.2 | 83 | 7.2 | 22.7 | 7.3 | 0 | muy_bajo | 1 |
| 2023-07-28 | 0 | 0 | 19.3 | 8.6 | 40 | 7.3 | 23.8 | 0.1 | 0.3 | muy_bajo | 1 |
| 2023-07-29 | 0 | 0 | 20.8 | 7.7 | 37 | 8.1 | 20.2 | 0.5 | 0.8 | muy_bajo | 1 |
| 2023-07-30 | 0 | 0 | 16.9 | 8.9 | 64 | 11.4 | 28.4 | 4.1 | 0.6 | muy_bajo | 1 |
| 2023-07-31 | 0 | 0 | 17.8 | 7.6 | 44 | 13 | 33.8 | 0.3 | 0.9 | muy_bajo | 1 |
| 2023-08-01 | 0 | 0 | 17.9 | 6.6 | 41 | 11.1 | 24.8 | 0.5 | 2 | muy_bajo | 1 |
| 2023-08-02 | 0 | 0 | 16.8 | 7.4 | 40 | 7.3 | 23.8 | 0.1 | 3.9 | muy_bajo | 1 |
| 2023-08-03 | 0 | 0 | 19 | 5.7 | 43 | 5.1 | 17.3 | 0 | 4.8 | muy_bajo | 1 |
| 2023-08-04 | 1 | 5 | 22.6 | 8.1 | 37 | 5.4 | 15.5 | 0 | 6.5 | bajo | 1 |
| 2023-08-05 | 0 | 0 | 25.4 | 9 | 29 | 5.9 | 15.8 | 0 | 8.7 | bajo | 1 |
| 2023-08-06 | 1 | 4 | 25.6 | 10.8 | 30 | 11 | 26.6 | 0 | 9.2 | bajo | 1 |
| 2023-08-07 | 0 | 0 | 22 | 11.7 | 39 | 12.5 | 31.7 | 1.8 | 11.9 | moderado | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: NBAC (NRCan), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 6,992ha
- official perimeter (CWFIS)
- Duration
- 31days
- 7 Jul 2023 – 6 Aug 2023
- Census subdivisions hit
- 1
- municipalities
- Started on
- 7 Jul
- 2023
- Heat detections
- 2,086
- in a single hotspot: 762 MW
- Danger at start
- 20
- Moderate · FWI index
- Average daily power
- 1.7GW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
7 Jul6 Aug
6 Aug 2023
How it evolved, day by day
8 Jul
11 Jul
16 Jul
21 Jul
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
26°high
48km/h · peak gust
27%lowest humidity
It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 1.8 mm on 7 Aug.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each census subdivision
-
Bulkley-Nechako B where it started6,961 ha reached on 8 Jul1.8 %
Burnt area inside each census subdivision, from crossing the official perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.
People and buildings inside the perimeter
GHSL 2025Built-up area< 0.1 ha
Residents< 20
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, satellite-based estimate).
This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned. The GHSL 2025 epoch is a projection made from 2020 and earlier data.
Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu
The weather day by day
ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.
Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 7 Jul | 25.5 °C | 27 % | 27 km/h | 1.7 mm | Moderate 20 |
| 8 Jul | 26.3 °C | 30 % | 24 km/h | 0.8 mm | Low 11 |
| 9 Jul | 24.2 °C | 40 % | 28 km/h | 0.5 mm | Moderate 12 |
| 10 Jul | 20.6 °C | 44 % | 38 km/h | 0.8 mm | Moderate 16 |
| 11 Jul | 21.5 °C | 27 % | 34 km/h | 0.0 mm | Moderate 16 |
| 12 Jul | 19.1 °C | 33 % | 24 km/h | 0.0 mm | Moderate 18 |
| 13 Jul | 19.3 °C | 37 % | 28 km/h | 0.0 mm | Moderate 19 |
| 14 Jul | 17.8 °C | 52 % | 24 km/h | 0.7 mm | Moderate 18 |
| 15 Jul | 20.2 °C | 38 % | 29 km/h | 0.2 mm | Moderate 21 |
| 16 Jul | 18.2 °C | 53 % | 21 km/h | 4.8 mm | Low 9 |
| 17 Jul | 16.6 °C | 43 % | 48 km/h | 0.0 mm | Low 6 |
| 18 Jul | 16.4 °C | 52 % | 39 km/h | 0.0 mm | Low 10 |
| 19 Jul | 23.1 °C | 33 % | 16 km/h | 0.2 mm | Moderate 11 |
| 20 Jul | 24.5 °C | 36 % | 28 km/h | 2.4 mm | High 22 |
| 21 Jul | 17.5 °C | 63 % | 29 km/h | 5.4 mm | Very low 1 |
| 22 Jul | 17.8 °C | 52 % | 34 km/h | 4.5 mm | Very low 1 |
| 23 Jul | 17.1 °C | 45 % | 22 km/h | 1.9 mm | Very low 0 |
| 24 Jul | 16.9 °C | 58 % | 19 km/h | 11.2 mm | Very low 0 |
| 25 Jul | 10.5 °C | 86 % | 40 km/h | 29.5 mm | Very low 0 |
| 26 Jul | 16.4 °C | 53 % | 47 km/h | 0.0 mm | Very low 0 |
| 27 Jul | 14.1 °C | 83 % | 23 km/h | 7.3 mm | Very low 0 |
| 28 Jul | 19.3 °C | 40 % | 24 km/h | 0.1 mm | Very low 0 |
| 29 Jul | 20.8 °C | 37 % | 20 km/h | 0.5 mm | Very low 1 |
| 30 Jul | 16.9 °C | 64 % | 28 km/h | 4.1 mm | Very low 1 |
| 31 Jul | 17.8 °C | 44 % | 34 km/h | 0.3 mm | Very low 1 |
| 1 Aug | 17.9 °C | 41 % | 25 km/h | 0.5 mm | Very low 2 |
| 2 Aug | 16.8 °C | 40 % | 24 km/h | 0.1 mm | Very low 4 |
| 3 Aug | 19.0 °C | 43 % | 17 km/h | 0.0 mm | Very low 5 |
| 4 Aug | 22.6 °C | 37 % | 16 km/h | 0.0 mm | Low 6 |
| 5 Aug | 25.4 °C | 29 % | 16 km/h | 0.0 mm | Low 9 |
| 6 Aug | 25.6 °C | 30 % | 27 km/h | 0.0 mm | Low 9 |
| 7 Aug after | 22.0 °C | 39 % | 32 km/h | 1.8 mm | Moderate 12 |
Its twins: fires that started in the same weather
It started with an FWI of 20.5, a minimum humidity of 27% and 5 days without rain. Fires in the area that started in weather like this since 2017: 16.
FWI at the start
20.5
Minimum humidity
27 %
Days without rain
5
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Bulkley-Nechako B fire, 7 July 2023
6,992 ha
31 days
FWI 20.5
Min. humidity 27 %
Cariboo I fire, July 2018
15,256 ha
39 days
FWI 20.0
Min. humidity 25 %
124 km away, in 2018
First rain (1 mm or more) after it ended: 2.6 mm on 7 Sept.
Cariboo I fire, July 2024
2,052 ha
65 days
FWI 22.0
Min. humidity 30 %
142 km away, in 2024
First rain (1 mm or more) after it ended: 4.4 mm on 21 Sept.
Bulkley-Nechako C fire, August 2024
1,426 ha
35 days
FWI 16.8
Min. humidity 29 %
102 km away, in 2024
First rain (1 mm or more) after it ended: 6.5 mm on 13 Sept.
Bulkley-Nechako E fire, July 2021
19,852 ha
48 days
FWI 17.1
Min. humidity 30 %
87 km away, in 2021
First rain (1 mm or more) after it ended: 1.9 mm on 25 Aug.
Cariboo I fire, August 2018
6,880 ha
17 days
FWI 27.1
Min. humidity 27 %
180 km away, in 2018
First rain (1 mm or more) after it ended: 3.9 mm on 25 Aug.
What happened to them
- 34 days
- median duration
- 3,616 ha
- median area
- 19 %
- went past 10,000 ha
- 4.3 mm
- rain at the end (median; 16 of 16 had it)
It was 1.9 times larger than the median of its twins and lasted 31 days, against 34 days.
Only 4 of its 16 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. All of them had rain in the ten days after the end: the first rainy day brought a median of 4.3 mm.
This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it
How it ended
1.8 mmfirst rain
7 Augthe day after it ended
48km/h · max. gust
It was considered over on 6 Aug, and on 7 Aug 1.8 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 16, with a median of 4.3 mm.
Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
How a twin is chosen
- Same area: fires that have already ended, less than 250 km from this one, since 2017.
- Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
- Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
- Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
- They are sorted by similarity, and the outlines of the first five are drawn.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 30 Jun 2023
After · 13 Aug 2023
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.
The smoke
CAMS · CopernicusOn 14 July 2023 the air beside the fire reached 1,803 µg/m³ of PM2.5. That day averaged 792: 53 times the WHO daily guideline (15).
PM2.5 peak1,803 µg/m³
Days over the guideline19 days
PM102,578 µg/m³
Optical depth9.09
WHO 15
5 Jul12 Jul19 Jul26 Jul2 Aug
Good
Fair
Moderate
Poor
Very poor
Extremely poor
Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.
Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)
Detections table · 2,086Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV
Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Bulkley-Nechako B fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 7 July 2023 to 6 August 2023 (31 days). The perimeter dates it from 7 July 2023 to 5 August 2023.
- How much area did it burn?
- The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 6,992 hectares (69.9 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
- Which census subdivisions burned?
- The fire only entered Bulkley-Nechako B (6,961 ha, 1.8 %).
- What was the weather like?
- During the fire the temperature reached 26.3 °C, humidity dropped to 27 % and gusts hit 48 km/h. The fire danger index (FWI) reached 22, class High.
- Where does this data come from?
- From the official burnt perimeter of Canada’s CWFIS (NBAC, Natural Resources Canada) or, for the current season and until NBAC publishes it, the one rebuilt by GWIS (Copernicus); from NASA FIRMS VIIRS hotspots; and from the administrative boundaries of Canada. It is not an official report.
- How did the fires that started in similar weather in this area end?
- Fires less than 250 km away that started since 2017 with a similar FWI, humidity and dry spell: 16. Their median duration was 34 days and their median area 3,616 ha; 19 % went past 10,000 ha. Only 4 of its 16 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. All of them had rain in the ten days after the end: the first rainy day brought a median of 4.3 mm.
Where to verify it
A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.
Emergency number: 911 · Emergency number and official warnings
- CIFFC · Canadian Interagency Forest Fire Centre ↗
- CWFIS · Canadian Wildland Fire Information System ↗
Satellite cross-check
History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 5 August 2023 → 6 August 2023.
RSS Changes to this page With cross-checks and a citable version
Does something look wrong on this page?
This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.
Report an error
How we know this
- Perimeter: NBAC (Natural Resources Canada), official.
- Dates adjusted with the VIIRS detections inside the perimeter, which said 7 July 2023 to 5 August 2023. 2,086 Suomi-NPP VIIRS detections on those dates.
- We have not matched this page with any official record.
- Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
- Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
Where this data comes from
The perimeter is official: it comes from the National Burned Area Composite (NBAC) of the Canadian Wildland Fire Information System (CWFIS), Natural Resources Canada, which maps it on satellite imagery and publishes it under the Open Government Licence – Canada. Until NBAC publishes the current season, this year’s fires carry the perimeter rebuilt from heat detections by GWIS (Copernicus, CC BY 4.0), which is approximate. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Census subdivision boundaries come from geoBoundaries ADM3 (Open Data Commons Open Database License 1.0). The area per census subdivision is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from official figures.