Tomorrow’s Tempo colour
Tomorrow’s colour as RTE publishes it, and what the day will cost you on your own consumption.
Tomorrow’s Tempo colour is set by RTE, France’s transmission grid operator, and published every day at 10:30 on its Tempo calendar; that publication, and only that one, binds the electricity suppliers. Between 08:00 and 10:30 RTE may put out a non-binding indication when its forecasts allow. The announced colour applies to the next Tempo day, from 06:00 to 06:00 the morning after, with off-peak hours from 22:00 to 06:00. A red day can only fall on a weekday between 1 November and 31 March. On the regulated tariff of 1 August 2026, a peak-hour kWh goes from €0.1654 on a blue day to €0.7295 on a red one: knowing the evening before leaves time to run the appliances, set the water heater and plan the heating. The tool above shows the colour as soon as our reading from RTE has picked it up and prices the day on your own consumption, so you can see what tomorrow means for your bill before it starts.
Tomorrow, a blue day, will cost you
€5
that day’s energy, standing charge excluded
| Same day on a blue day | €5 |
| On a white day | €5 |
| On a red day | €16 |
| On the Off-peak option | €6 |
kWh prices incl. tax from 1 August 2026; red peak: €0.7295.
Checked by Radif Partners · Editorial policy · Method and sources
Who decides the colour, and when
Since 1 November 2014 Tempo days have been chosen by RTE, which runs the high-voltage grid, rather than by a supplier. The regulator’s deliberation behind it sets the quotas and the calendar; RTE’s method note describes the algorithm. Each morning RTE compares the next day’s expected net demand, national consumption minus wind and solar, with two thresholds that drop as the season goes on and the stock of days runs down. A freezing, windless Monday in January is very likely to be red; a mild, breezy Tuesday will stay blue.
The decision goes out at 10:30 on RTE’s Tempo calendar. It applies to every Tempo customer, whatever the supplier, for the day that starts at 06:00 the next morning.
The last fourteen days
| Day | Date | Colour |
|---|---|---|
| Sunday | 18 October 2026 | Blue |
| Saturday | 17 October 2026 | Blue |
| Friday | 16 October 2026 | Blue |
| Thursday | 15 October 2026 | Blue |
| Wednesday | 14 October 2026 | Blue |
| Tuesday | 13 October 2026 | Blue |
| Monday | 12 October 2026 | Blue |
| Sunday | 11 October 2026 | Blue |
| Saturday | 10 October 2026 | Blue |
| Friday | 9 October 2026 | Blue |
| Thursday | 8 October 2026 | Blue |
| Wednesday | 7 October 2026 | Blue |
| Tuesday | 6 October 2026 | Blue |
| Monday | 5 October 2026 | Blue |
The table follows the page’s latest reading. Days still to come have no colour until RTE publishes it. The whole season, day by day, is on the Tempo days left page, and past winters are in the Tempo history.
The evening before a red day
A colour published at 10:30 leaves roughly nineteen hours before the red day starts at 06:00. That is enough to move most things:
- run tomorrow’s washing, drying and dishwasher loads tonight after 22:00;
- warm the house a little more overnight, at the red off-peak rate of €0.1615, and let it cool slowly between 06:00 and 22:00;
- finish charging the car before 06:00 and resume at 22:00;
- plan a meal that needs little oven or hob time.
The guide what to do on a red day prices each of these moves appliance by appliance.
How often this page updates
The page rebuilds itself automatically several times a day: shortly after 10:30 to catch RTE’s publication, twice more in the late morning in case a reading is late, and just after midnight to roll over to the new date. In your browser the cards line up with Paris time: between midnight and 06:00 they remind you that the current Tempo day is still yesterday’s. If RTE cannot be reached, the page keeps its last successful reading and shows its date.