Buenos Aires enters autumn on May 18, 2026, when typical highs range from 16°C to 19°C. The market asks whether the maximum temperature will land at exactly 12°C—well below seasonal average, indicating a significant cold outbreak. The 1% YES odds suggest traders view this outcome as highly unlikely, reflecting Buenos Aires' historical tendency toward mild autumn temperatures. For this outcome to occur, a strong cold front from the south or unusual weather system would need to push into the region. The current price implies strong conviction in warmer or more moderate temperatures, though short-term meteorological data could shift expectations. Buenos Aires weather markets attract traders focused on precise temperature predictions; exact-degree markets emphasize forecasting precision over directional moves. The low volume ($645 in 24h) and tight liquidity ($6,041) suggest this is a specialized market for weather enthusiasts. This recurring daily market allows traders to test predictions against actual outcomes, with resolution occurring after 00:00 UTC on May 18.
What factors could move this market?
Buenos Aires' May climate sits at the transition between late autumn and early winter in the Southern Hemisphere. Historically, May highs average 16–18°C, with lows near 9–10°C. A peak of exactly 12°C would represent a morning-like temperature persisting through the afternoon—nearly 5–6 degrees below seasonal norms. Such an outcome requires unusual atmospheric dynamics: either a powerful cold front sweeping from Patagonia northward, or an extended high-pressure system anchoring cold polar air over the region. The 1% YES odds reflect traders' collective assessment that warming or neutral patterns dominate May 18. Buenos Aires sits on the Pampa, a relatively flat plain with minimal orographic forcing, making extreme temperature swings less common than in mountainous regions. Late May frontal systems do bring cooler air, but they typically moderate by afternoon, allowing highs to creep back toward 14–16°C. For the high to remain stuck at exactly 12°C, the cold air mass would need to persist throughout daylight hours—a low-frequency event. Recent Southern Hemisphere meteorological patterns show variable cold-outbreak timing. Some May cycles brought sudden crashes of 8–10 degrees; others saw gradual moderate cooling. The specificity of this market—not just "below 15°C" but exactly 12°C—compounds the forecasting difficulty. Temperature measurements at Buenos Aires' official station (Observatorio Central) define resolution; station methodology governs outcomes. Trader conviction appears polarized: 1% YES odds pit a small contrarian group against a vast majority expecting mild conditions. The $645 daily volume is modest, suggesting limited speculative activity. Precedent from earlier May markets shows that 12°C or colder events occur roughly 2–4 times per decade, aligning with current market odds. Watch for meteorological alerts from Argentina's weather service and global model consensus shifts—rapid cold-front predictions could rebalance odds sharply in the final hours.
What are traders watching for?
Argentina's weather service alerts or temperature anomaly warnings issued before evening May 17
GFS and ECMWF ensemble consensus on May 18 high temperature relative to seasonal 16–18°C norms
Real-time station readings from Observatorio Central after 17:00 UTC May 17 indicating morning trajectory
Documented polar air mass persistence or tropical air intrusion intensity observed by early morning May 18
How does this market resolve?
Market resolves YES if the highest temperature recorded at Buenos Aires' Observatorio Central is exactly 12°C on May 18, 2026 (00:00–23:59 UTC). Any other recorded high temperature results in NO resolution.
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