![Weekly fuel price oscillation in Helsinki area in Finland [OC]](https://www.byteseu.com/wp-content/uploads/2026/01/ammxzk7mkjfg1-1536x576.png "Weekly fuel price oscillation in Helsinki area in Finland [OC]")
I visualized the recent fluctuation of 95E10 petrol prices across various gas stations in the Helsinki metropolitan area. The plot shows data from late 2025 (Week 48 – Week 52). The local newspaper Helsingin Sanomat has discussed this price oscillation phenomenon in the Helsinki region, which has been observed for years. There is no clear explanation for this phenomenon, where prices often jump up simultaneously across stations on Tuesday or Wednesday and then slowly drift downwards over the subsequent days. You can read more about it here (in Finnish): https://www.hs.fi/pkseutu/art-2000008244136.html
Visualization Details:
- Black dots: Individual price reports from varying stations.
- Line: 1-day moving average determining the general price trend.
- Y-axis: Price in €/liter.
Sources:
- Data Source: polttoaine.net (crowdsourced fuel prices in Finland), collected via Home Assistant.
Tools Used:
- Python (Matplotlib, Pandas)
- Home Assistant (data history collected daily from polttoaine.net with HA script)
Posted by _luo-d-e_
3 Comments
Looks like you found a way to make easy money
Usually fuel is the cheapest on Tuesdays, because it’s when fuel stations get deliveries.
Here’s another little tip: Neste stations have slightly cheaper fuel ( 1-3eurocents/L ) at the self-service; but if a station has a restaurant attached then it tends to be a little more expensive, unless you have a K-bonus card, in which case you can get 5eurocents/L cheaper