Markets settled by a specific thermometer at a specific station. The forecast is public; the conventions are the edge.
Weather markets look like the fairest fight on Kalshi: the settlement data comes from government stations, the forecasting models are public, and no insider knows tomorrow's high before the atmosphere does. That surface fairness hides a game of conventions, which station, which time window, which rounding, that decides a surprising share of outcomes.
The honest structure of the category: within about three days, modern forecasts are excellent and prices track them tightly, so edges are thin and convention-driven. Beyond five to seven days, forecast skill decays toward climatology, and prices that imply confidence at that horizon are usually implying too much.
Every market names its exact observation station and time window. A city's 'high temperature' means the reading at one specific station (often the major airport), on the measurement day the rules define, not what your phone's weather app, averaging different sources, shows for the metro area.
Thresholds settle on the official recorded value at the stated precision. A market on '90 degrees or above' is decided by whether the station logs 90, and days that feel like near-misses are decided by instrument and convention, not vibes.
Precipitation markets carry their own conventions: trace amounts, the measurement window's clock (local standard time matters), and which gauge counts. Rules first, forecast second.
Model literacy is the honest edge. The major global and regional models publish on known schedules several times daily, and their agreement or divergence is readable by anyone willing to learn. When models converge and the market still prices yesterday's uncertainty, the reprice is predictable in direction.
Climatology is the base rate casual money skips: how often this station has historically hit this threshold on this calendar date. For horizons past a week, climatology plus a trend beats any point forecast, and prices set by point-forecast confidence at those horizons are the mispricing.
Station quirks persist: some stations read systematically warm or cool versus the metro perception, coastal stations behave differently from inland ones, and the person who has watched one station's behavior for a season prices its markets better than the person forecasting 'the city'.
Conditions where the trade is usually worse than it looks. Any one of these firing is a reason to pass.
Proceed only after you have checked the specific thing named.
The conditions under which taking the trade is actually defensible.
Field guides are educational and describe historical patterns and mechanics; nothing here is a recommendation to trade any market. Rules quoted generically; the specific market’s rules page always governs. Not financial advice.