Japan’s kerosene stocks sit at 20,523 kbbl (Aug 2026), the highest among all eight refined product categories — 1.18x diesel (17,464 kbbl) and 1.58x gasoline (12,991 kbbl). This isn’t inert inventory: it’s a structural signal of winter heating demand onset. Kerosene makes up 19.6% of Japan’s total refined stocks — well above the seasonal 8–12% range (industry norm). Mechanically, household kerosene heating is temperature-triggered; sustained sub-10°C readings from November force immediate restocking. JODI’s two-month lag means August stocks reflect September–October vessel arrivals. Gasoline stocks at 12,991 kbbl are near five-year lows (industry norm), confirming post-summer demand fade. Diesel at 17,464 kbbl looks ample — but Japan’s refinery throughput (2,349 kbpd) is 21% below Korea’s (2,977 kbpd), making its diesel import margin tighter and more price-sensitive. Regional reality: Japan discloses no SPR refined-product breakdown — commercial stocks alone manage seasonal swings. Current kerosene volume equals ~32 days of static consumption (based on 2025 JODI avg. 640 kbpd, industry norm); gasoline covers only 20 days, diesel 27. That means an early November cold snap will directly compete for import quotas against naphtha and fuel oil — the latter sitting at just 6,327 kbbl, the lowest among all refined products and below Korea’s 7,852 kbbl. For SNSUC clients, this isn’t forward guidance — it’s current vessel constraint: Tsushima Strait AIS traffic stands at 43 vessels/day, vs. historical norm of 63 — port arrival pace has already slowed. But kerosene vessels take priority over fuel oil. Upside trigger: USD/JPY break below 156.00 or Nikkei single-day drop >3% accelerates yen depreciation and import cost pressure, forcing pre-emptive kerosene price locks. Downside trigger: Tokyo average temp >14°C in first week of November delays restocking, potentially dragging kerosene drawdown to <35 kbbl/day (industry norm). Bias: Bullish. Shift to neutral only if kerosene stocks rise MoM by >5% for two consecutive months. Action for SNSUC importers: Initiate Nov-mid kerosene pricing window now — cap at Brent +$12.50/bbl. For SNSUC traders: Pause Dec fuel oil contract bookings; reserve cargo space for emergency kerosene lifts. FX hedge: Layer 50% of Dec cargo payments at USD/JPY 157.00–157.50. Wait for: JMA cold-snap warning issued ≤48h before Nov 1.