Stunning weather for the last couple of weeks had meant none of the earlier concerts had been canned.
In previous years alternative covered venues were often found in adverse weather, however, organisers were not as lucky this weekend, Mr Leiser said.
"We haven't been able to find suitable venues for this weekend."
Both concerts would potentially be rescheduled for the end of the season, he said.
Concert-goers would be able to look forward to Deco Bay Brass for Summer In The Park and BFM Trio featuring Margot Wuts for Jazz In The Village Green the following week.
"We will be back with a vengeance next weekend."
The Little Blast Orchestra is a seven-piece chaos swing ensemble which plays a mix of jazz tunes from the pre-bop era.
Sonic Delusion's music is regarded as Latin-infused, pop-laced, funky electroacoustic folk.
Summer in the Park has been running in Cornwall Park for more than 18 years offering free concerts every Sunday from the end of January to the end of February.
The final Mitre10 Mega Outdoor movie will now be played at Pettigrew Green Arena this evening instead of Bay Skate.
Ticket prices for the Kiwi classic Hunt for the Wilderpeople have been cut to $5 with under 3s free.
Those who have already paid $10 for tickets have the choice of either a free Lick This icecream during intermission or an additional ticket – both valued at $5.
The doors will open at 5.50pm, and the movie will start at 6.30pm as advertised.
Seating will be in the grandstand or on the court, blankets, low sand chairs and cushions are welcome, as are home-made picnics.
Please bring cash as not all vendors will not have eftpos available.
