[9] With the exception of years featuring higher than average rainfall, wildfires in the United Kingdom typically occur in two spells between March and April and July and September,[10] and are uncommon before spring.

[3][11] The United Kingdom had previously experienced a large number of wildfires in the summer 2018 following spells of high temperatures and low levels of precipitation in the preceding months.

[13] This was caused by a high pressure system over central Europe driving air from southern latitudes towards the United Kingdom and Ireland, bringing dry, settled conditions and unseasonably warm weather.

[16] Comparatively low rainfall over the winter was also suggested as increasing the probability of the wildfires, with the lack of moisture combining with the high temperatures in February to dry out vegetation, creating an easily flammable source within the grasslands and moorlands at an earlier stage of the year than usual.

[4] Two separate fires reported one hour apart struck Ashdown Forest in West Sussex that afternoon, affecting 14 hectares (35 acres; 0.054 sq mi) of woodland,[18] with a third noted shortly afterwards.

[18] It was later revealed that the first two fires had been unintentionally started by volunteers clearing gorse from the woodland, with an unexpected rush of wind and warm temperatures blowing a managed burn out of control.

[22] The same night saw approximately 800 square metres (0.20 acres; 960 sq yd) of gorse burn at Arthur's Seat in Edinburgh, prompting almost 200 calls to the emergency services.

[26] More than 280 hectares (690 acres; 1.1 sq mi) of moorland was affected, destroying more than £200,000 of habitat restoration work and imperiling the nesting sites of some species of birds, such as curlews, whose populations in the United Kingdom are considered under threat.

[27] By 23 April the National Trust, the owners of Marsden Moor, reported that the fire had spread to cover 3,700 hectares (9,100 acres; 14 sq mi) and described it as the most substantial blaze to hit the area for years.

[30] Thirty-five firefighters also tackled a 100 hectares (250 acres; 0.39 sq mi) fire near Ballindalloch in Moray that evening, and helped by a helicopter waterbombing the area the blaze was extinguished by the afternoon of 15 April.

[32] On 19 April the SFRS issued a wildfire warning and urged the public to abide by the Scottish Outdoor Access Code to minimise any further risk of fire formation.

[citation needed] In Wales a series of grassland fires on the Gower peninsula were reported over three days to 15 April, causing local road closures and raising concerns over the potential ecological damage.

[38] That evening two large grassland fires fanned by strong winds spread in Rhondda Cynon Taff and Rhigos before being extinguished the following morning.