Every Polymarket weather market resolves on a reading published by an official source, for one named location, over one defined period. Everything else, including our own estimate, is commentary. This guide covers what that reading is for each market type and the mistakes that most often cost people money.
Temperature: which reading settles it
The daily maximum or minimum recorded at the station named in the market rules, over the local calendar day. Check the rules for the exact station. A city can have several reporting stations and they do not agree.
Rain: the monthly accumulation
Total precipitation recorded at the named gauge across the calendar month, in the market's stated unit.
Air quality: the daily PM2.5 figure
The daily figure published by the reporting authority, normally a 24 hour mean, in micrograms per cubic metre.
Four mistakes that cost money
Wrong station. Trading a city's weather rather than the station's. Look up the ICAO in the market rules.
Wrong day boundary. The settlement day is midnight to midnight in the station's timezone. If you are on the other side of the world, the market's day is not your day.
Reading a morning number as the day's high. Before the afternoon peak, a running maximum is close to meaningless. A high can only rise.
Rounding. Buckets are defined on the rounded official figure. A reading of 24.6 that the source publishes as 25 settles the 25 bucket.
Glossary
Term
Meaning
Bucket
One outcome, for example "23°C" or "86-87°F".
Settlement station
The station whose official reading decides the market, named by its ICAO code.
Running extreme
The highest or lowest reading so far today. Monotone: a high only rises.
Locked
Informal: the extreme has passed and is very unlikely to change.
Implied probability
The market price of a bucket, read as a probability.
Risk. Prediction markets carry risk and you can lose money. Nothing here is financial advice. Past results do not predict future results.