West Sussex Fire & Rescue Service received reports of a fire at property in Broadfield at 6.41pm.
Crews were met with a fire in the large roof space at Webb Close, but firefighters extinguished the blaze with hose reels, jets and thermal imaging cameras.
West Sussex Fire & Rescue Service reported no casualties at the incident, but warned residents in northern Sussex to take ‘extra care’ during the hot weather.
The Met Office's Fire Severity Index is currently 'high' in the northern areas of West Sussex, which includes, Horsham, Crawley, East Grinstead and Petworth.
The blaze in Broadfield was the second fire crews attended on Tuesday. West Sussex Fire and Rescue Service said it received reports of a fire at a derelict property in Goffs Park Road, Southgate at around 1.20pm yesterday afternoon.
A spokesperson for West Sussex Fire & Rescue Service said: "At 6.41pm yesterday (5 September) we received reports of a fire at a property in Webb Close, Broadfield.
"Upon arrival crews were met with a large fire in the roof space, which is believed to have been started accidentally.
"Firefighters wearing breathing apparatus extinguished the fire using high pressure hose reels, jets and thermal imaging cameras.
"Fortunately there were no casualties.
"The Met Office's Fire Severity Index is currently 'high' in the northern areas of West Sussex, including Petworth, Horsham, Crawley and East Grinstead. This is an assessment of how severe a fire could become if one were to start.
"We would urge all residents to take extra care in this weather by moving mirrored and glass objects away from direct sunlight, avoid having barbecues in the countryside and making sure that cigarettes are fully extinguished."