How Temperature Markets Settle

The NWS Climatological Report (CLI) is the official daily weather summary for a station. It includes the day's official high temperature, low temperature, and average — calculated from raw sensor data (one-minute observations) without the additional rounding layers that affect publicly displayed temperatures.

Critically, CLI data has undergone NWS review. Faulty sensor readings are adjusted or removed. Temporary station outages are noted. This is what makes it the authoritative record.

The CLI is why you might watch a temperature all day and see 70°F displayed, but the official record settles at 69°F or 71°F. The displayed value went through the rounding pipeline; the CLI used raw sensor data.

Kalshi's daily temperature rules name The Weather Company first, then the National Weather Service, as the source of the official high or low for the market's NWS climate location (for example CLINYC for Central Park). The rules cite the value as published on The Weather Company's Kalshi data portal (weather.com/kalshi), and the first non-preliminary value counts. That official value is the station's NWS daily climate record, which minuteTemp tracks through the CLI report.

Kalshi settles a market once the official value is published, so there is no fixed settlement window: most daily markets settle roughly 3 to 12 hours after they close at midnight, and some not until the early afternoon ET. minuteTemp records settlement outcomes from Kalshi's API, tracking which markets resolved and at what value.

For example, if a Kalshi market asks "Will NYC's high be above 75°F?" and the official high is 74°F, the "No" contracts pay out — regardless of whether real-time observations briefly showed 75°F or 76°F during the day. See Kalshi weather markets for every city's station and Kalshi hourly temperature markets for the hourly markets.

Coinbase lists Kalshi's temperature markets, operated by Kalshi: the same tickers, order book and stations. Settlement follows Kalshi's rules for each market, so a market settles the same way on Coinbase as on Kalshi. Coinbase's prediction markets are not available to Nevada or Michigan residents. See Coinbase weather markets for the series it lists and Coinbase hourly temperature markets for the hourly ones.

Polymarket (polymarket.com, the international exchange) temperature markets do not use the CLI. For most cities their rules name NOAA's weather.gov timeseries for the market's station as the resolution source: a daily high resolves on the highest “Temp” reading of the local calendar day, and a daily low on the lowest. US markets use the hourly data (“Show Hourly Data”) in whole °F; other cities use the station's readings in whole °C. Weather Underground's Daily Observations table is used only if NOAA's data for the day is unavailable by 11:59 PM ET the next day. Some cities also use a different station than Kalshi, such as LaGuardia (KLGA) for New York and O'Hare (KORD) for Chicago.

A few cities differ. Taipei (RCSS) settles on Weather Underground's Daily Observations table in whole °C, not NOAA. Hong Kong settles on the Hong Kong Observatory's Daily Extract to 0.1 °C; minuteTemp does not cover it.

On the dashboard, minuteTemp's Polymarket estimate follows the same rule: for US stations, the highest or lowest routine hourly METAR, rounded to whole °F as NOAA's table shows it; for other NOAA cities, every METAR in whole °C; for Taipei, the same METARs, which are the rows of Weather Underground's table. NOAA's hourly view also lists some special reports (SPECI), so on a rare day the official value can differ from the estimate.

The rules can vary by market, so check each market's resolution criteria on Polymarket for the exact data source. See Polymarket temperature markets for every city's event slug and station.

Polymarket US is a separate, CFTC-regulated US exchange with its own markets and order books. Its daily high markets (New York, Chicago, Miami, Los Angeles, San Francisco and Philadelphia) and daily low markets (New York and Chicago) settle on the National Weather Service's Daily Climate Report (CLI) for Central Park (KNYC), Midway (KMDW), KMIA, KLAX, KSFO and KPHL. Kalshi uses the same stations, but its rules name The Weather Company first and the NWS second; Polymarket US names the NWS report itself.

Because the source is the CLI, the day is the NWS climate day (midnight to midnight local standard time), the same as Kalshi. Settlement is normally the next morning, around 8am ET.

Robinhood's temperature markets are ForecastEx contracts: ForecastEx is the exchange, and Robinhood is a broker, so they are not Kalshi contracts. Interactive Brokers lists the same ForecastEx contracts, and also Kalshi's daily high for Austin, Chicago, Denver, Houston, Los Angeles, Miami and New York. The rules below apply to its ForecastEx contracts only; its Kalshi contracts follow Kalshi's rules and station, and minuteTemp shows them under Kalshi.

Daily high and low (UH and UL products, such as UHLGA and ULLGA) settle on the Weather Underground Daily Observations table for one airport station: the maximum temperature shown for the local calendar day for highs, the minimum for lows. The day is final once the first observation of the next day is published, and settlement is normally no later than the day after expiration. Strikes are thresholds 1 °F apart rather than brackets: high contracts ask whether the high will exceed a strike (“exceed 85 F”), low contracts whether the low will be below one (“below 52 F”).

The station can differ from Kalshi's: New York uses LaGuardia (KLGA), not Central Park (KNYC), and Denver uses Buckley Space Force Base (KBKF), not Denver International (KDEN).

Hourly (HRU products, on Robinhood for a few cities): each hour T, Central Time, settles on the last Weather Underground observation for the station after T − 60 minutes and up to T, in whole °F, with the NWS time series as the fallback. The hour is final once Weather Underground publishes the first observation after T. See Robinhood weather markets for every city's products and station, Robinhood hourly temperature markets for the HRU contracts and IBKR temperature markets for what Interactive Brokers lists.

It's common for the CLI to report a high or low that differs from what you tracked in real-time. This happens because:

• •Rounding differences: Real-time data goes through the F→C→F rounding pipeline; CLI uses raw sensor values
• •Sensor corrections: NWS may remove outlier readings from a malfunctioning sensor
• •Averaging differences: CLI uses 2-minute averaged one-minute data; public feeds may use instantaneous or differently averaged values

• •Station outages: If a station goes offline during the observation period, the CLI may note missing data. Market resolution rules vary by platform for these scenarios.
• •Corrected readings: Occasionally the NWS corrects a CLI after initial publication. Some platforms have provisions for amended reports.
• •Multi-station cities: Different stations may report different temperatures. Know which station the market references — e.g., Kalshi's NYC markets reference Central Park (KNYC), while Polymarket and the ForecastEx contracts on Robinhood and IBKR use LaGuardia (KLGA).