LONDON, April 21 (Reuters) - British wholesale day-ahead gas prices edged higher on Friday morning, on expectations of cooler temperatures next week.
* British day-ahead gas price up by 0.10 pence to 39.20 pence per therm at 0944 GMT.
* Within-day contract up by 0.10 pence to 39.25 p/therm.
* Traders said temperature was the key driver but that outages at coal and nuclear plants had also increased demand for gas from gas-fired power stations.
* Britain's Met Offices said temperatures could hit highs of 16 degrees Celsius in the south of the country on Friday but said colder conditions were expected across the country next week.
* Gas-fired power plants supplied around 50 percent of Britain's electricity on Friday, with zero supply coming from coal-fired plants.
* Four of Britain's 15 nuclear reactors, with a combined capacity of 2.3 gigawatts, are offline.
* Just one liquefied natural gas tanker is scheduled to arrive in Britain over the next week.
* May gas contract up by 0.05 pence to 39.10 p/therm.
* Day-ahead gas price at the Dutch TTF hub up by 0.13 euro to 16.23 euros per megawatt hour.
* Benchmark Dec-17 EU carbon contract down by 0.04 euro to 4.71 euros per tonne.
* Thomson Reuters (Dusseldorf: TOC.DU - news) analyst view: http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageid=united-kingdom-gas (Reporting by Susanna Twidale; Editing by Mark Potter)