Gas has a season. Oil mostly doesn't.
November 2026Illustrative, not for reserves or investment decisions
Before comparing one month of production with another, it helps to know what is normal for that month. We added up reported production for Alberta, Saskatchewan and BC from January 2022 to September 2026 and measured how far each calendar month usually sits above or below its own yearly trend. The answer is very different for gas and for oil.
What we did
- Data: province-wide monthly totals from the same public files as the other posts (Petrinex for Alberta and Saskatchewan, the BC Energy Regulator for BC). Totals are a sum of well-level rows, so they are not official provincial statistics.
- Rate: monthly volume divided by calendar days, so short months do not look low.
- Seasonal effect: each month's rate divided by a centred 12-month moving average, minus one. We average that for each calendar month across the years where it can be computed (four years, 2022 to 2025).
1. Gas moves with the seasons
Alberta gas runs about 10% above trend in January and 9% in December, and about 7% below it in May and 6% in September. BC gas follows the same shape (6% above in January, 7% below in September). Saskatchewan gas barely has a season (between +2% and −2%).
| Series | Highest month | Lowest month | Swing |
|---|---|---|---|
| Alberta gas | Jan (+9.8%) | May (−7.2%) | 17 points |
| BC gas | Jan (+5.9%) | Sep (−7.1%) | 13 points |
| Saskatchewan gas | Apr (+2.4%) | Jan (−2.4%) | 5 points |
| Alberta oil | Nov (+2.4%) | May (−3.5%) | 6 points |
| Saskatchewan oil | Apr (+2.3%) | Jun (−2.5%) | 5 points |
The winter peak and late-spring to autumn trough are consistent with winter demand and summer maintenance, but this data shows what happened, not why. The Alberta gas swing is about 17 points from peak to trough month.
2. Oil is much flatter
Alberta oil moves within about 6 points over the year (weakest in May at −3.5%, strongest in Nov at +2.4%), and Saskatchewan oil within about 5 points. Those are small next to the gas swings, and with four years of data a single unusual month can move them. We left BC oil out because its totals are small and noisy.
What this means in practice
- When a gas month is up or down 5 to 10% on the previous month, check the calendar before reading anything into it. Compare with the same month a year earlier instead.
- For oil, month-to-month moves are mostly not seasonal, so a change of a few percent is more likely to be real.
- A decline curve fitted to a gas well should expect seasonal bumps; a fit that ends on a winter peak will look more optimistic than one ending in the summer.
Limits
- Only four years per calendar month. A one-off event, for example a wildfire evacuation or a pipeline outage, can move the average for a single month.
- The totals include only what appears in the public well-level files, and recent months can be revised.
- Alberta oil includes crude bitumen from wells licensed for it, so its small seasonal swing partly reflects bitumen operations.
- The trend adjustment is a simple moving average and cannot separate seasonality from a steady rise or fall within a year.
Reproduce it
Code: github.com/Jay-Kimani/TidyWells, posts/monthly_agg.py and posts/gen_posts.py. Download the files yourself from Petrinex and the BC Energy Regulator; we do not host the data.
Illustrative only. Not for reserves reporting or investment decisions.
Contains information licensed from Petrinex public data (Alberta, Saskatchewan) and the BC Energy Regulator; Crown copyright of the provinces is acknowledged. Tidywells is not affiliated with any regulator.