Australia’s deadly wildfires are showing no signs of stopping. Here’s what you need to know

Australia is being ravaged by the worst wildfires seen in decades, with large swaths of the country devastated since the fire season began in late July.

At least 28 people have died nationwide, and in the state of New South Wales (NSW) alone, more than 3,000 homes have been destroyed or damaged. State and federal authorities are struggling to contain the massive blazes, even with firefighting assistance from other countries, including the United States.

All this has been exacerbated by persistent heat and drought, and many point to climate change as a factor making natural disasters go from bad to worse.

Where are the fires?

A satellite image of the bushfires burning across Australia on December 26.

There have been fires in every Australian state, but New South Wales has been hardest hit.

Blazes have torn through bushland, wooded areas, and national parks like the Blue Mountains. Some of Australia’s largest cities have also been affected, including Melbourne and Sydney – where fires have damaged homes in the outer suburbs and thick plumes of smoke have blanketed the urban center. Earlier in December, the smoke was so bad in Sydney that air quality measured 11 times the “hazardous” level.

Haze from the bushfires is seen over Sydney's Bondi Beach on December 10, 2019.

The fires range in area from small blazes – isolated buildings or part of a neighborhood – to massive infernos that occupy entire hectares of land. Some start and are contained in a matter of days, but the biggest blazes have been burning for months. In NSW alone, more than 100 fires are still burning.

What is causing the fires?

Each year there is a fire season during the Australian summer, with hot, dry weather making it easy for blazes to start and spread.

Natural causes are to blame most of the time, like lightning strikes in drought-affected forests. Dry lightning was responsible for starting a number of fires in Victoria’s East Gippsland region in late December, which then traveled more than 20 kilometers (12.4 miles) in just five hours, according to state agency Victoria Emergency.

Humans can also be to blame. NSW police have charged at least 24 people with deliberately starting bushfires, and have taken legal action against 183 people for fire-related offenses since November, according to a police statement.

Animal rescuer Marcus Fillinger carries a burned kangaroo on February 4 in Peak View, Australia. Fillinger tranquilized the wounded animal for transport to a recovery center.

A bushfire burns near the town of Bumbalong, south of Canberra on February 2.

Horses panic as a fire burns near Canberra, Australia, on Saturday, February 1.

A firefighter coats a bridge with foam as a bushfire burns near Moruya, Australia, on Saturday, January 25.

In this long-exposure photo, a car's taillights streak at left as a wildfire glows at dusk near Clear Range, Australia, on Friday, January 31.

An airplane dumps fire retardant behind houses at the foot of Mount Tennent as fire creeps through the Namadgi National Park in Canberra on Thursday, January 30.

People embrace near the scene of a water tanker plane crash in Cooma, Australia, on Thursday, January 23. Three American crew members died in the crash.

Flying embers are seen in this long-exposure photo from Moruya on Thursday, January 23.

A young koala named Jeremy receives medical attention for burns at the Healesville Sanctuary in Badger Creek, Australia, on January 23.

Firefighters battle the Morton Fire as it burns a home near Bundanoon, Australia, on January 23.

The Parliament House in Canberra is blanketed by bushfire smoke on January 23.

A firefighter battles the Morton Fire as it consumes a home near Bundanoon on January 23.

Veterinarian Ludo Valenza holds two grey-headed flying foxes, which were being treated for bushfire injuries at the Australia Zoo Wildlife Hospital in Beerwah, Australia, on Wednesday, January 15.

Lt. Kynan Lang from the 10th/27th Battalion visits the scene where his uncle and cousin died in a bushfire on Australia's Kangaroo Island.

A smoky haze from bushfires hovers over the Melbourne skyline ahead of the Australian Open tennis tournament on Tuesday, January 14. Poor air quality disrupted the qualifying rounds of the tournament.

Properties damaged and destroyed by fire are seen in Nerrigundah, Australia, on Monday, January 13.

Debris remains where houses stood in the Australian village of Wingello on January 13.

Bonnie Morris and sister Raemi Morris look on as their family and firefighters battle bushfires at the edge of their family farm in Karatta on Saturday, January 11.

Pictures of firefighters are projected onto the Sydney Opera House on January 11.

A vehicle makes its way through thick fog mixed with bushfire smoke in the Ruined Castle area of the Blue Mountains on January 11.

Protesters march through downtown Melbourne on Friday, January 10, in response to the ongoing bushfire crisis.

An aerial view shows a track running through trees that were scorched by bushfires in East Gippsland, Australia, on Thursday, January 9.

A pile of wood chips burns at a timber mill in Eden, Australia, on January 9.

Lisa Poulsen tends to her Clydesdale horse, Jake, on January 9. Jake suffered burn injuries in a bushfire on December 31.

A small wave of black water full of burned debris breaks at a beach at Eden on January 9.

A dead kangaroo lies on a burnt farm in Batlow.

A firefighter backs away from flames after lighting a controlled burn near Tomerong on January 8.

Stephenie Bailey is embraced on Wednesday, January 8, as she describes the impact the bushfires have had on her farm in Batlow.

Charlotte O'Dwyer, the young daughter of Rural Fire Service volunteer Andrew O'Dwyer, wears her father's helmet during his funeral after being presented with a service medal in his honor by RFS Commissioner Shane Fitzsimmons on Tuesday, January 7, in Sydney.

A resident throws a bucket of water onto a smoldering tree on his property on Monday, January 6, in Wingello, Australia.

A military helicopter flies above a burning woodchip mill in Eden, New South Wales, on January 6.

A Royal Australian Navy MH-60R Seahawk "Romeo" helicopter refuels onboard HMAS Adelaide during Operation Bushfire Assist, on Sunday, January 5, in this image provided by the Australian Department of Defence. HMAS Adelaide and army reserve forces have been assisting with bushfire evacuations on the southern coast of New South Wales.

Families are evacuated by air from Mallacoota on January 5.

A man walks past ash from bushfires washed up on a beach in Merimbula on January 5.

The flight deck of a C-130J Hercules is lit by the red glow of the fires below as the aircrew attempts to land in Merimbula to drop off fire and rescue crews to assist fighting the bushfires on January 5.

This satellite image provided by NASA on Saturday, January 4, shows smoke from fires burning in Victoria and New South Wales.

A father holds his daughter as the skies above turn red during the day on January 4 in Mallacoota, Australia. Many parents with young children were stuck in Mallacoota after flights were grounded because of smoke and only school-aged children and older were allowed to evacuate by boat.

A Royal Australian Navy crew unload luggage as evacuees from Mallacoota arrive aboard the MV Sycamore on January 4 at the port of Hastings, Australia.

Smoke from wildfires shrouds a road near Moruya, Australia, on January 4.

Nancy Allen stands outside her house as high winds push smoke and ash from the Currowan Fire toward Nowra in New South Wales on January 4.

Evacuees board the Royal Australian Navy's MV Sycamore on January 3 in Mallacoota, Victoria, Australia. Navy ships plucked hundreds of people from beaches and tens of thousands were urged to flee before hot weather and strong winds in the forecast worsen Australia's already devastating wildfires.

Massive smoke rises from wildfires burning in East Gippsland, Victoria on January 2.

Royal Fire Service Commissioner Shane Fitzsimmons presents a posthumous Commendation for Bravery and Service on January 2 to the son of RFS volunteer Geoffrey Keaton, who was killed battling bushfires, at Keaton's funeral in Buxton, New South Wales.

Boats are pulled ashore as smoke and wildfires rage on January 2 behind Lake Conjola.

Cars line up as people evacuate the town of Batemans Bay in New South Wales on January 2.

A satellite image released by Copernicus Sentinel dated December 31 shows bushfires burning across Australia.

A kangaroo rushes past a burning house in Lake Conjola, Australia, on December 31.

A man tries to defend a property in Lake Conjola on December 31.

Firefighters hose down trees as they battle against bushfires around the town of Nowra in the Australian state of New South Wales on December 31, 2019. Thousands of holidaymakers and locals were forced to flee to beaches in fire-ravaged southeast Australia on December 31, as blazes ripped through popular tourist areas leaving no escape by land.

A destroyed home in Sarsfield, East Gippsland, Victoria, on December 31.

Children evacuated from areas affected by bushfires play at the showgrounds in the southern New South Wales town of Bega on December 31.

A skycrane drops water on a bushfire burning near houses in Bundoora, Melbourne, on Monday, December 30.

The National Oceanic and Atmospheric Administration (NOAA) captured this satellite image of the historic bushfires burning across Australia on December 26.

Australian Prime Minister Scott Morrison is briefed by fire officials at New South Wales Rural Fire Service control room in Sydney on December 22. Morrison arrived back in Sydney amid criticism after taking a family holiday to Hawaii during the bushfire emergency.

Tributes for volunteer firemen Andrew O'Dwyer and Geoffrey Keaton are seen at Horsley Park Rural Fire Brigade in Sydney, Australia, on December 22. It's believed they were killed when their vehicle hit a tree before rolling off the road, the New South Wales Rural Fire Service said in a statement.

A firefighter battles the Gospers Mountain Fire in Bilpin, New South Wales, on Saturday, December 21.

A charred bicycle lies on the ground in front of a house destroyed by bushfires on the outskirts of Bargo on December 21.

Fire and rescue personnel monitor a bushfire as it burns near homes on the outskirts of Bilpin on Thursday, December 19.

A property burns in Balmoral on December 19.

A helicopter drops fire-retardant to protect a property in Balmoral.

Police disperse demonstrators during a climate protest near Australian Prime Minister Scott Morrison's official residence in Sydney, on December 19, during his absence on an overseas holiday, as bushfires burned across the region.

Children swing into the Penrith river during a heatwave in Sydney on December 19.

A landscape of burnt trees is pictured after a bushfire at Mount Weison, in the Blue Mountains, on Wednesday, December 18.

A wallaby flees a fire burning near Mangrove Mountain, north of Sydney, on December 10.

A smoke haze blankets Bondi Beach as the air quality index reaches higher than ten times hazardous levels in some suburbs of Sydney on December 10.

People join a guided climb of the Sydney Harbour Bridge as bushfire haze darkens the sky on December 6.

People are seen wearing face masks to protect against the poor air quality in Sydney on December 5.

A bushfire burns out of control in the Blue Mountains of New South Wales on December 2,

An aerial view shows bushfires burning in the Richmond Valley on November 26.

A CFA crew member rests after a day of maintaining controlled back burns in St Albans, Australia, on November 21.

An injured koala receives treatment after its rescue from a bushfire at the Port Macquarie Koala Hospital on November 19. The hospital said the fires have "decimated" the area, which is a key habitat and breeding ground for the marsupials. More than 350 koalas are feared to have been killed by bushfires in NSW, according to animal experts.

Firefighters try to protect the Colo Heights Public School on November 19.

Bushfire smoke clouds the sky over the Hawkesbury River in Brooklyn, Australia.

Firefighters work on controlled back burns on November 14.

This satellite image shows wildfire smoke on November 14.

A man uses a wet towel to help put out flames near the town of Taree on November 14.

Firefighters organize their crews prior to working on controlled back burns in Sydney on November 14.

Warren Smith pats his dog after returning to find his house destroyed near Nana Glen on November 13.

Teresa de Ruyter, left, and Michelle Wilson embrace after returning to their homes near Nana Glen on November 13.

Firefighters battle a spot fire in Hillville on November 13.

Residents look on as thick smoke rises from bushfires near Nana Glen on November 12.

Australian Prime Minister Scott Morrison looks at a screen as he gets a briefing on the bushfire situation on November 12.

Locals watch the fires impact farmland near Nana Glen on November 12.

A firefighter mops up after a bushfire in the Sydney suburb of Llandilo on November 12.

A fire and rescue team inspects damage around the village of Torrington on November 11.

Andrew Mackenzie surveys the damage to the area around his home in Torrington. His home was spared, but his neighbors' house was burned to the ground.

Smoke from the Gulf Road Fire fills the air in Glen Innes on November 11.

A sign on a Taree fire station warns of "catastrophic" fire conditions.

A lone joey is pictured on a scorched patch of ground in Torrington on November 11.

Emergency crews tend to animals on a property in Torrington on November 11.

Burnt trees dot the landscape in Old Bar on November 10.

A firefighter works to contain a bushfire near Taree on November 10.

A helicopter drops water on a bushfire in Old Bar on November 9.

This aerial photo, taken on November 9, shows bushfires in the northeastern part New South Wales.

Fires burn in the distance as children play on a beach in Forster on November 9.

A fire rages in Bobin on November 9.

The remains of a property are seen in Bobin on November 9.

A plane drops fire retardant on a bushfire in Harrington on November 8.

Firefighters try to put out a bushfire in Woodford on November 8.

Police knock on the door of a house to warn residents of an out-of-control bushfire near Clumber on November 8.

A resident hoses smoldering logs as a bushfire burns in Woodford on November 8.

The sun is seen through heavy smoke as a bushfire burns in Woodford.

Firefighters hose down an area in Woodford.

Forster residents watch as a water-bombing helicopter flies over a bushfire on November 7.