Polymarket’s weather vertical trades $244.72M across 39 active city markets today, with London attracting the largest share at $62.13M. The British capital’s forecast high ranges narrowly from 32°C to 33.3°C, reflecting a tight consensus among sources.
Chicago emerges as the most contested market, where forecast highs diverge sharply between 74°F and 90.3°F, a 16.3°F gap. This wide spread, paired with $6.87M in volume, marks it as the most unsettled and tradable question in weather markets today. For context, Chicago’s actual high yesterday was 79°F, placing the market’s range both below and well above that figure.
Other cities illustrate geographic and forecast diversity. New York City sees $55.13M traded with a 4.2°F forecast spread between 67°F and 71.2°F, showing moderate disagreement. Seoul’s market of $19.70M features a tight 0.5°C spread from 25.5°C to 26°C, indicating strong consensus in East Asia. Meanwhile, Atlanta and Dallas present wider forecast gaps of 13.1°F and 14.8°F respectively, with $9.38M and $9.34M traded, highlighting volatility in southern U.S. weather predictions.
These variations reveal where forecast models diverge and markets find opportunity. Meanwhile, cities with narrow ranges reflect more aligned expectations across sources, limiting market friction. Tracking these patterns helps map where weather uncertainty persists and where markets are most engaged.
Today’s most active weather markets
| City | Volume | Forecast high | Spread |
|---|---|---|---|
| London | $62.13M | 32°C–33.3°C | 1.3°C |
| New York City | $55.13M | 67°F–71.2°F | 4.2°F |
| Seoul | $19.70M | 25.5°C–26°C | 0.5°C |
| Atlanta | $9.38M | 81°F–94.1°F | 13.1°F |
| Dallas | $9.34M | 86°F–100.8°F | 14.8°F |
| Ankara | $7.42M | 27.7°C–29°C | 1.3°C |
| Wellington | $7.42M | 11.7°C–13°C | 1.3°C |
| Seattle | $7.42M | 70°F–80.6°F | 10.6°F |
| Buenos Aires | $7.37M | 16.3°C–18°C | 1.7°C |
| Toronto | $7.11M | 30°C–31.7°C | 1.7°C |
| Chicago | $6.87M | 74°F–90.3°F | 16.3°F |
Source: Polydata API v3 · /weather/cities · snapshot 2026-07-08. Data: Polydata API v3. On-chain figures are public. Realized PnL is computed over resolved markets only and excludes open positions, so it is conservative versus the Polymarket UI. This is not investment advice.