* Day-ahead gas was up 1.25 pence at 29.75 pence per therm by 0800 GMT.
* Within-day gas was up 1.75 pence at 30.00 p/therm, a level last seen on May 30.
* Planned annual outages in Norway capped exports, although flows were already being reduced last week ahead of the work.
* Maintenance work began over the weekend on the Trolls field, one of the largest in the North Sea, cutting flows by 42 million cubic metres (mcm) a day.
* Work on the Emden field has impacted flows of 33 mcm, while the Aasta Hansteen field will have an outage next week, reducing flows by 23 mcm.
* In addition, two other Norwegian fields experienced unplanned outages over the weekend, although flows have resumed since then.
* Total gas supplies from Norway were a touch higher on Monday at 82 mcm compared to 78 mcm on Friday, but below the 100 mcm seen earlier last week before the outages.
* Putting further pressure on supplies, sendout rates from liquefied natural gas (LNG) terminals are at 16 mcm, lower than the more than 50 mcm a day seen for most of this year. Sendout rates have been depressed since last week and no LNG tankers are scheduled to arrive in the coming days, shipping and port data showed.
* The system was undersupplied with demand forecast at 197.7 mcm and supplies expected at 189.7 mcm, according to National Grid data.
* Demand is 30 mcm higher than the seasonal norm due to chillier weather on Monday, which is expected to last for several days.
* Average temperatures are seen at 11.2 degrees Celsius on Monday and 11.8 degrees Celsius on Tuesday, both below a seasonal norm closer to 14 degrees.
* Peak wind generation is expected to be just 4.0 gigawatts (GW) compared to a total metered capacity around 12.1 GW, although that is expected to rise to 6.6 GW on Tuesday, Elexon data shows.
* Further along the curve, the July contract eased 0.05 pence to 28.75 p/therm.
* The day-ahead gas price at the Dutch TTF hub was up 0.47 euros at 11.45 euros per megawatt hour.
* The benchmark Dec-19 EU carbon contract rose 0.64 euros to 25.15 euros a tonne.