Crews from across the area were variously called to a garage fire in Havant, a caravan fire in Southsea, and three suspected arson incidents in Leigh Park.
And malicious a 999 call reporting a house fire in Worcester Road, Somers Town, at 12.45am has prompted a warning from Southsea watch manager Jamie Wren.
He said: 'We got called to a domestic fire but when we got there it turned out to be a false alarm, malicious.
'We requested the attendance of the police who are now dealing with it.
'We're then tied up with that, rather than potentially responding to an incident should we be required.
'While at that we may have been required elsewhere.'
Two appliances and eight firefighters were tied up with the incident for around 30 minutes.
At the same time in Shepherd Way, Havant, crews were called to a garage fire, where the roof had collapsed in on the garage.
Crew manager Glenn Kavanagh said: 'The garage was completely destroyed. As we arrived the roof had collapsed on the building.
'We had to stop it from spreading to the house.
'It melted and caused heat damage to the fascia of the property.'
Around six people in total from the homes either side were evacuated. A Subaru car suffered heat damage when its bumper and number plate were melted by the heat of the blaze.
At least 12 firefighters, with two crews from Cosham and one from Havant, tackled the fire.
Four breathing apparatus crews were used to put out the fire, thought to have been caused by an electrical fault. The exact cause is under investigation.
Crews were there until 3.30am but returned later this morning to check on the property.
Havant had earlier been called to a fire in underneath a car's engine compartment on the A3 southbound just before the Bedhampton and Waterlooville turn off at 6pm.
While on standby as the garage fire was dealt with, Fareham firefighters were called to a suspected arson of a mattress on fire in Merryfield Avenue, Leigh Park, at 1.25am.
The mattress had been put up against a fence of a property, with damage caused to the fence.
And at 2.25am a Fareham crew was called to a moped on fire at Barncroft Way, Leigh Park. It is also suspected to be arson.
A crew from Havant was later called to a bin fire at 5.12am, which was also suspected arson.
Elsewhere, at 5.18am a Southsea crew was called to The Italian Bar & Grill. in Great Southsea Street, with smoke billowing from a pizza oven.
No damage was caused but the oven was thought to have been left on overnight.
At 6.14am two crews from Southsea tackled a caravan fire in Ferry Road, Portsmouth.
Nobody was in the vehicle and it was completely destroyed by fire.
Crews had to remove propane cylinders and cool them down.
Police said the occupier has been found temporary accommodation.