The price of gas for delivery the next day was 39.10 pence per therm at 0738 GMT, 0.20 pence lower than the previous close.
Gas for delivery at the weekend was down 0.30 pence at 38.40 pence per therm.
Britain's gas system was oversupplied by around 6 million cubic metres (mcm) of gas on Friday, National Grid data showed.
Demand was forecast to be around 170 mcm, below seasonal normal demand of 182 mcm.
Gas flows were expected to be 176 mcm/day. Britain is set for warmer-than-average weather in the coming week, with temperatures in a range of around 17-22 degrees Celsius, peaking in the London area over the weekend, according to meterologists.
Temperatures traditionally average around 16 degrees in June. Warmer weather generally reduces demand for gas for heating systems and temperatures are not yet high enough to prompt demand for high levels of air conditioning.
On the supply side, flows of gas from the UK Continental Shelf were around 111 mcm/day on Friday, but nominations suggest there are higher flows going into several gas terminals, analysts said. A nomination is a request for a specific quantity of gas under a purchase or sales agreement.