Beginner Guide

How to write clear weather market questions

Practical rules and templates for writing precise weather market questions that settle cleanly

By Top Prediction Markets EditorialReviewed August 5, 20263 min read

Answer first

Clear weather market questions remove doubt about what counts as the measured event. State the exact location (station), the settlement time window, units and rounding, the data source, and a fallback rule. Use simple thresholds and model templates for temperature, precipitation and wind.

What it means

In simple terms, a weather market question defines a single measurable event that will be checked against an objective data source at settlement. The goal is to make it obvious whether the outcome is Yes or No.

Here's the basic idea: pick one place, one time window, one measurement method, and one dataset. Write that into the question so different readers don't interpret it differently.

Why it matters

The key thing to know is that ambiguity causes disputes and delays. When a question leaves room for interpretation, traders, moderators, and resolvers may disagree about which data to use.

  • Ambiguity lowers confidence in prices and in the market's usefulness.
  • Clear wording reduces moderator burden and speeds settlement.

How it works

  1. Choose the exact observation point. Use an official station name and identifier when possible (for example: "KBUF — Buffalo Niagara International Airport").
  2. Define the time window. Use an unambiguous start and end with time zone or UTC (for example: "00:00–23:59 local time on 2026-09-01").
  3. Specify the measurement and units. Say "daily maximum temperature in degrees Fahrenheit, rounded to the nearest 0.1°F" or "total liquid precipitation in millimeters, 24-hour accumulation."
  4. Name the primary settlement source (dataset and provider) and a single, clear fallback rule if that source is unavailable.
  5. State how to interpret thresholds (inclusive vs exclusive). Use >= or > language in plain English: "at least 75°F (>= 75.0°F)" or "greater than 0.00 in (>)".

Follow that order when you draft a question: station, window, measurement, units/rounding, data source, fallback, threshold logic.

A simple example

A simple example of a settled trade: Suppose a Yes contract — an event contract that pays $1 if the event happens — costs 62¢ for the question, "Will the daily maximum temperature at KSEA (Seattle–Tacoma International Airport) reach at least 75.0°F on 2026-08-01, local date? Primary source: NOAA Integrated Surface Database (ISD) daily summary for station 727930-24231. If ISD is unavailable, use the NWS official daily summary for KSEA. Rounding: maximum observed temperature rounded to nearest 0.1°F."

Buying one Yes contract costs $0.62. If the NOAA record shows a maximum of 76.3°F on that date, the contract pays $1, so the gain before fees is $0.38. If the maximum is 74.9°F, the contract expires at $0, so the loss is $0.62.

Common mistakes

Missing the station identifier

Listing only a city name ("New York") leaves open whether you mean Central Park, JFK, LaGuardia, or Newark. Name the station and, if available, its code.

Vague time window

"Tomorrow" or "this week" creates timezone and endpoint disputes. Specify calendar dates and the exact hours that define the observation window.

Not saying how values are rounded or measured

A value of "0.049 in" may round to 0.0 or 0.05 depending on rules. Specify rounding and whether measurements are liquid-equivalent precipitation.

No fallback or ambiguous source

Saying "official NWS" without naming the dataset or table forces resolvers to pick. Always name the dataset and give one unambiguous fallback dataset with a clear rule for when to use it.

Related concepts

Frequently asked questions

What exactly should I put in the location field?

Give a named observation station and its identifier when available (airport code or WMO/ICAO station ID). If the station is not standard, describe coordinates and the nearest town.

How should I phrase thresholds to avoid confusion?

Use both plain English and a mathematical form. Example: "at least 75.0°F (>= 75.0°F)." State rounding rules explicitly.

What do I do if the primary data source is missing?

Name a single fallback source and the conditions that trigger it (for example: "If ISD is unavailable or has no daily summary for this station, use NWS daily summary for the same station"). Avoid multiple fallbacks.

Are weather markets legal?

Rules vary by location and platform. See our dedicated guide on whether prediction markets are legal in the US.

Can I use nearby stations instead of the named station?

Only if you specify that in the question. If you allow nearby stations, define a maximum distance and an order of preference (nearest station within X km). Otherwise, use the named station only.

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