The gains are likely to prove shortlived as Asian buyers are facing the prospect of lower import costs for the first winter since the Fukushima nuclear crisis in 2011, with rising supplies helping to ease any shortages.
Spot LNG contracted in October for delivery to Japan averaged $15.30 per million British thermal unit (mmBtu), up from $13.20 from a month earlier, the Ministry of Economy, Trade and Industry (METI) said.
Cargoes arriving last month averaged $12.40 per mmBtu, compared with $11.30 in September.
Asian spot LNG prices rose to $15 per mmBtu in late September, but have declined steadily since then to $12.90 per mmBtu last week, bucking a seasonal rise in prices at this time of the year.
Japan, which takes about a third of the world's LNG imports, shipped in a record 87.73 million tonnes in the year through March.
The average spot price is based on about 10 percent of the nation's purchases of the super-chilled fuel.
Japan started releasing spot LNG prices in April to add transparency to the market amid concern about rising fuel costs in the wake of the shutdown of nuclear plants after the Fukushima crisis.
The METI survey looks at samples of fixed prices for LNG sold to power companies and utilities among others, and excludes
spot deals linked to benchmark prices such as the US natural gas Henry Hub index.