Day-ahead gas rose 1.75 pence to 26.00 pence per therm by 0800 GMT.
Gas for within-day delivery rose 2.25 pence to 25.00 p/therm.
The UK gas system was undersupplied with demand forecast at 209.5 million cubic metres (mcm) and supplies seen at 201.5 mcm, National Grid data showed.
Gas for power demand was expected to rise 14 mcm to 62 mcm as peak wind generation falls to 6.9 gigawatts (GW) from 12.1 GW on Friday.
The power sector tends to use more gas when wind generation drops off; last week peak wind was at or close to capacity for a number of days.
The residential gas demand forecast was increased only slightly to 126 mcm even though the temperature forecast was cut by 3.1 degrees Celsius to 10.6 degrees.
On the supply side, send-out rates from liquefied natural gas (LNG) terminals fell mainly due to a 7 mcm reduction from the Isle of Grain facility.
However, another LNG tanker has declared for Britain, bringing the total due by the end of the month to six.
Flows along the Langeled pipeline from Norway increased by 20 mcm.
But that was partially offset by an unexpected outage at the Culzean gas field, which has impacted 5 mcm of supplies although ramp up has begun, REMIT messages show.
The British month-ahead price slipped 0.15 pence to 42.00 p/therm.
The Dutch month-ahead gas contract, a benchmark for LNG prices, slid 0.05 euro to 15.99 euros per megawatt hour.
The Dutch day-ahead price at the TTF hub rose 0.33 euro to 9.68 euros per megawatt hour.
The benchmark Dec-19 EU carbon contract fell 0.46 euro to 23.98 euros per tonne.