San Francisco June 11 High Temp: Will It Stay at 81°F or Below?

San Francisco’s microclimate is one of the most misunderstood weather systems in the United States. The city’s famous fog machine — driven by cold Pacific upwelling and the marine layer — keeps summer highs suppressed well below inland California readings. The market is pricing the primary outcome, 81°F or below, at just 36.5% probability. That number is lower than San Francisco’s historical June baseline would suggest, and the gap between the data and the price is exactly where the interesting questions live.

The market question asks what the highest temperature in San Francisco will reach on June 11, 2026. The primary outcome pays YES if the high lands at 81°F or below. The contract resolves at noon Pacific on June 11. Total volume stands at $19,826, with all of that trading in the last 24 hours. The market opened this question fresh.

How the San Francisco Temperature Contract Works

This is a multi-outcome temperature bracket market. Each bracket covers a two-degree Fahrenheit range. The primary outcome — 81°F or below — pays YES if the official high for San Francisco on June 11 falls within that range. The higher brackets pay if temperatures exceed that ceiling. Resolution follows the official measurement record for San Francisco.

• YES (81°F or below) is priced at $0.37, implying a 36.5% probability that San Francisco stays at or under 81°F.
• The NO side, priced at $0.64, reflects the market’s collective view that San Francisco is more likely to exceed 81°F on June 11 than to stay within it.

For the primary outcome to miss, San Francisco’s official high on June 11 must exceed 81°F. The city’s marine layer typically suppresses June highs into the mid-60s along the coast and low-to-mid 70s inland near monitoring stations. A reading above 81°F requires a specific synoptic setup: an offshore flow pattern, a building inland heat dome, or a temporary breakdown of the marine layer. These setups do occur in June — San Francisco recorded highs above 85°F multiple times in the last decade — but they are not the default mode for early June.

Sponsored Partner

Momentum and Market Signals

The momentum composite here is mixed. The trend score sits at 54.62, which is slightly above neutral. The 1-hour price change is flat at zero percent, and the 24-hour baseline does not apply because this market launched within the last 24 hours. The price opened at $0.33 and moved up to $0.37, a roughly 12% lift from open, with volatility during the session — the price hit $0.47 intraday before pulling back. That intraday spike and retreat suggests traders are actively disagreeing about the forecast setup for June 11.

Total volume is $19,826 and all of it landed in the current 24-hour window. Liquidity stands at $34,348, which is healthy relative to volume. This is a thin market by dollar terms, and the intraday swings confirm it: a single large directional bet can move this price sharply before resolution. Traders should treat the current price as a live forecast, not a settled consensus.

Key Factors

• The 1-hour price change is flat at zero percent, but the intraday range from $0.33 to $0.47 and back to $0.37 reflects active disagreement about the June 11 forecast.
• The 24-hour price movement of roughly plus 12% from open to current suggests early buyers leaned toward higher temperature outcomes before partial reversal.
• Liquidity at $34,348 exceeds volume at $19,826, meaning the order book can absorb new trades without large slippage — but thin absolute dollar terms mean a focused position still moves price.
• San Francisco’s June climatology strongly favors highs below 70°F along coastal stations and below 75°F at inland monitoring points, making the 81°F threshold a meaningful outlier bar.
• No whale trades are recorded in this market. The price signal reflects retail-level participation, which may be more reactive to short-term forecast headlines than to historical climatology.

Lines Analysis: San Francisco’s Marine Layer vs. the Heat Bracket

Here’s what the measurements are telling us. San Francisco’s June climatology is one of the most stable warm-season baselines in North America. The average June high at San Francisco International Airport runs in the low-to-mid 60s Fahrenheit. The average June high at downtown monitoring stations runs slightly warmer, but still well below 81°F. For the primary outcome to pay YES, the city simply needs to behave like San Francisco in June. That is the baseline condition, and the data favors it heavily.

What makes the NO side real is the Diablo Wind scenario. Offshore flow events in the Bay Area can spike temperatures dramatically, even in June. When the pressure gradient reverses and dry, compressional air flows from the Central Valley toward the coast, the marine layer retreats. San Francisco has recorded June highs above 85°F during these events. The market at 36.5% YES is implying roughly a one-in-three chance that San Francisco stays cool — which feels pessimistic relative to the historical frequency of marine layer breakdown events in early June.

Signals to Monitor

• The National Weather Service San Francisco Bay Area forecast for June 11 is the single most important data point. Any NWS forecast showing highs above 75°F for San Francisco proper should push the primary outcome probability lower.
• A 500-millibar ridge building over the interior West by June 10 to 11 is the synoptic pattern most associated with Bay Area heat events. Check upper-level forecast maps.
• The marine layer depth forecast for June 10 night into June 11 morning matters. A deep, persistent marine layer anchors cool temperatures. A shallow or retreating layer opens the door to warming.
• Any NWS Excessive Heat Watch or Advisory for the Bay Area interior issued before June 11 would signal elevated probability of marine layer breakdown reaching San Francisco proper.
• Model consensus from the GFS and European models for the June 11 San Francisco high is the sharpest available signal and should anchor any final positioning.

Total volume of $19,826 is thin. The data favors the primary outcome based on climatology, but the market is pricing a meaningful heat-event probability. If the NWS forecast for June 11 shows San Francisco highs in the mid-60s to low 70s, the 36.5% YES probability looks underpriced. If forecast models show an offshore flow pattern developing, the current pricing is reasonable. The data doesn’t care about the politics — it cares about the pressure gradient over the Bay on June 11.

LINES VERDICT

Climatology Favors the Cool Side

San Francisco’s marine layer is the most reliable temperature suppressor on the West Coast in June, and the primary outcome simply requires the city to behave normally. The current 36.5% YES price looks pessimistic relative to the historical frequency of below-81°F days in early June San Francisco.

What the market says: At 36.5%, the market is pricing roughly one-in-three odds that San Francisco stays at or below 81°F on June 11. The market is pricing uncertainty, not science — and given how rarely San Francisco exceeds 81°F in June without a specific synoptic trigger, that probability deserves scrutiny before the contract resolves at noon Pacific on June 11.

Key unknown: The single most important input is the NWS forecast for San Francisco proper on June 11, specifically whether forecast models show an offshore flow event or Diablo Wind pattern developing by June 10 evening. That forecast, issued in the hours before resolution, will reprice this contract decisively.

What is the probability that San Francisco hits 81°F or below on June 11?

The market currently prices that outcome at 36.5%. San Francisco’s June climatology strongly favors highs well below 81°F, but a specific offshore flow pattern can push temperatures above that threshold even in early summer.

What does the NO side pay out on?

The NO side pays if San Francisco’s official high on June 11 exceeds 81°F, meaning any outcome in the 82-83°F bracket or higher resolves the primary YES outcome as false.

What data would move this price before resolution?

A National Weather Service forecast update for June 11 showing San Francisco highs above 75°F or an offshore flow advisory would push the primary outcome probability lower. A marine layer forecast holding through the day pushes it higher.

When does this contract resolve?

The contract resolves at noon Pacific time on June 11, 2026, based on the official temperature record for San Francisco on that date.

How reliable is the volume signal here?

Total volume is $19,826 with all trading in the last 24 hours. This is a thin market. Price can move sharply on a single directional trade or a weather forecast update before resolution.