Canada CPI all-items year-over-year inflation, May 2026

Realized month-over-month change in the all-items YoY rate over the last 5 transitions = [+0.2, -0.1, -0.5, +0.6, +0.4]; mean = +0.12pp, population stdev = 0.39pp. Recent-3 mean = +0.17pp (upward drift). An 80% interval is roughly last value +/- 1.28*0.39 ~ +/- 0.50pp.

Reference class: month-to-month moves in Canada's all-items CPI YoY rate. Moves have ranged -0.5 to +0.6pp over six months; the median absolute move is ~0.36pp. Energy-driven episodes (like the current one) tend to plateau once the steepest base effect annualises, arguing for a flatter May than the +0.4/+0.6 jumps of March/April.

Gasoline's YoY contribution should remain elevated in May (May-2025 gasoline was still soft), but the largest mechanical jumps are behind us and ex-gasoline inflation is easing. Net: roughly flat to slightly up from April's 2.8%. Point estimate 2.8%.

Lands outside [2.3, 3.3] if: a renewed oil/gasoline surge from the conflict pushes headline to ~3.4-3.5 (upside tail), or the updated basket-weight rebasing plus an energy pullback drags it toward ~2.1-2.2 (downside tail). The basket-weight change is a genuine non-Gaussian wildcard for the May print specifically, so tails are modestly fatter than the realized stdev implies; I widened the band to +/-0.5 partly for this.

The resolver is the first Statistics Canada May 2026 all-items CPI 12-month change for Canada, not seasonally adjusted, published in The Daily and Table 18-10-0004-01 to one decimal percent.

Base-rate reference class: the last five headline prints were 2.4, 2.3, 1.8, 2.4, and 2.8 percent, averaging 2.34 percent, while the latest three-month average was about 2.33 percent. The near-term trend and energy shock argue above that base, but not far above April because April already incorporated a large gasoline and carbon-levy base effect.

Counter-consideration: if Middle East-linked oil prices or local gasoline prices rose further through May, the print could exceed 3 percent; if the full-month fuel excise tax suspension and softer shelter or travel components dominated, May could fall toward the low 2s.

Anchor on April 2.8. Add about +0.1 for continued energy pass-through and recent upward momentum, subtract about -0.2 for April-specific base effects and a full month of fuel-tax relief, giving 2.7. Use an 80% interval of 2.1 to 3.4 to cover typical one-month CPI surprise plus unusually high gasoline volatility.

The control run starts from April headline CPI and fades the gasoline base effect without decomposing the basket.

The pack run keeps the control's energy base-effect caution but leaves a wider upper tail for gasoline and basket-weight uncertainty.