Skip to content
worldfires
IE · Ireland ·

Castlebar LEA-7 fire, April 2021 Castlebar LEA-7

Out · last detection 24 Apr 2021, 14:09 UTC

The fire started on 24 April 2021 in Castlebar LEA-7, Ireland, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 347 hectares from satellite imagery, spread across a single municipality.

This entry is probably a heather, gorse or hill-grazing burn, not a wildfire. In the UK and Ireland moors and hillsides are burnt every winter and spring to renew grazing or heather. This is our assumption, based on the time of year, ground with almost no woodland and the lack of news about this fire; it is not confirmed. That is why it is left out of the wildfire rankings.

Burnt area
347ha
Copernicus perimeter
Duration
1day
24 Apr 2021 – 24 Apr 2021
Municipalities hit
1
local electoral areas
Started on
24 Apr
2021
Heat detections
17
in a single hotspot: 34 MW
Danger at start
8
Low · FWI index
Average daily power
454MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Apr24 Apr

How it evolved, day by day

24 Apr 2021 · 454 MW · 17

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

18°high
38km/h · peak gust
37%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 2.1 mm on 2 May.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

What happened to each town

  1. Castlebar LEA-7 where it started
    348 ha reached on 24 Apr
    0.4 %

Burnt area inside each municipality, 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.

What burned

  • Other natural land87 %
  • Agricultural areas7.8 %
  • Scrub and transitional woodland5.2 %

Natura 2000 protected area affected: 12 %

Natura 2000 sites (European Environment Agency, 2024 release) crossed by the perimeter.

Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.

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)
24 Apr 18.2 °C 37 % 38 km/h 0.0 mm Low 8
25 Apr after 17.7 °C 49 % 33 km/h 0.0 mm Low 8
26 Apr after 15.8 °C 51 % 39 km/h 0.0 mm Low 8
27 Apr after 11.7 °C 72 % 56 km/h 0.8 mm Low 8
28 Apr after 11.3 °C 54 % 45 km/h 0.0 mm Low 8
29 Apr after 10.1 °C 66 % 40 km/h 0.8 mm Low 6
30 Apr after 11.0 °C 43 % 34 km/h 0.2 mm Very low 5
1 May after 11.3 °C 55 % 33 km/h 0.6 mm Very low 4
2 May after 10.5 °C 57 % 29 km/h 2.1 mm Very low 2

Its twins: fires that started in the same weather

It started with an FWI of 8.2, a minimum humidity of 37% and 4 days without rain. Fires in the area that started in weather like this since 2016: 19.

FWI at the start 8.2
Minimum humidity 37 %
Days without rain 4
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Fermanagh and Omagh fire, May 2017
666 ha 2 days FWI 8.4 Min. humidity 39 % 137 km away, in 2017

First rain (1 mm or more) after it ended: 9.2 mm on 12 May.

What happened to them

3 days
median duration
300 ha
median area
5 %
went past 1,000 ha
5.0 mm
rain at the end (median; 16 of 19 had it)

It burned an area similar to its twins (347 ha against a median of 300 ha) and lasted 1 day, against 3 days.

In 3 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 5.0 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

2.1 mmfirst rain
2 May8 days after it ended
38km/h · max. gust

It was considered over on 24 Apr, and on 2 May 2.1 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 19, with a median of 5.0 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 2016.
  • 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.

How we calculate it

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 17 Apr 2021
After · 1 May 2021

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 · Copernicus

On 22 April 2021 the air beside the fire reached 27 µg/m³ of PM2.5. That day averaged 17: 1.1 times the WHO daily guideline (15).

PM2.5 peak27 µg/m³
Days over the guideline1 day
PM1034 µg/m³
22 Apr24 Apr26 Apr
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 · 17Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Ireland

Frequently asked questions

How long did the Castlebar LEA-7 fire last?
Copernicus dates it between 24 April 2021 and 24 April 2021: 1 day between the first and last image with fire.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 347 hectares (3.5 km²). Official national figures may differ.
Which municipalities burned?
The fire only entered Castlebar LEA-7 (348 ha, 0.4 %).
What was the weather like?
During the fire the temperature reached 18.2 °C, humidity dropped to 37 % and gusts hit 38 km/h. The fire danger index (FWI) reached 8, class Low.
Where does this data come from?
From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Ireland (geoBoundaries). 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 2016 with a similar FWI, humidity and dry spell: 19. Their median duration was 3 days and their median area 300 ha; 5 % went past 1,000 ha. In 3 of 19, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 5.0 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: 999 · 112 · Emergency number and official warnings

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 999 · 112.

How we know this
  • Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 17 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.
  • Probably a vegetation burn: not counted in the totals.

How we build fire pages: methodology

Where this data comes from

The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM2 (Creative Commons Attribution 4.0 (CC BY 4.0)). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.