Weather Fi
Sign in
OpenAgriculture · Growing-season heatWeather index future · simulation

Chicago growing degree days · Week 48 · Nov 23 - Nov 29

Growing degree days at KORD · 7 local days, 2026-11-23 to 2026-11-29 · trading closes 11-29 06:00 (15 d)

Market index
5.8°C-days
Long 20.1¢ · Short 79.9¢ per share
Model fair
1.0 ± 2.0
priced 23 min ago
Edge
-4.8
fair minus market
Volume
467
13 traders
Open interest
94 / 587
long / short shares
0 · long pays 0long pays 1 · 29
Market 5.8Model fair 1.0
Listed at 8.4 · quoted by a market maker, no order book · one share moves 0.0345 sUSDT per index point

Real-asset futures that follow this index

simulated prices

Each contract below is a commodity price index the demo simulates: 100 on the day it was listed, moved by this contract's GDD and by a simulated market factor. Weather-implied is the price at the index this market is trading at now; when it differs from the asset's own market price, simulated spread traders trade the two against each other.

ContractMarket priceWeather-implied
CORN-KORD-26W48Corn108.70long 57¢107.27

How the index builds, day by day

ForecastBeyond the forecast

Each bar is one local day's contribution to the index. Days with a final NWS climate report count as they stand (shown as final record); a day whose report is not out yet uses the METAR figure and is marked not final; the rest are the model's estimate, with a whisker one standard deviation either way.

0.01.02.011-2311-2411-2511-2611-2711-2811-29
Day-by-day table
DaySourceHighLowGDDRunning total
Mon, Nov 23Forecast30.2°F23.5°F0.0 ± 0.00.0
Tue, Nov 24Forecast32.4°F23.0°F0.0 ± 0.10.0
Wed, Nov 25Forecast35.6°F25.7°F0.0 ± 0.20.0
Thu, Nov 26Forecast41.7°F27.9°F0.2 ± 0.60.2
Fri, Nov 27Forecast47.5°F32.9°F0.7 ± 1.20.8
Sat, Nov 28Beyond the forecast35.4°F27.7°F0.1 ± 0.30.9
Sun, Nov 29Beyond the forecast35.4°F27.7°F0.1 ± 0.31.0

Market index path

one step per trade · dashed line: model fair now
0.05.210.3

Recent trades

TimeTradeSharesAmountAvg price
11-13 19:50Buy short42.8734.1279.6¢
11-13 18:50Buy short53.8442.4278.8¢
11-13 17:50Buy short75.3258.5277.7¢
11-13 15:50Buy short78.6160.0076.3¢
11-13 13:50Buy short79.0959.2274.9¢
11-13 10:50Buy short81.8260.0073.3¢
11-13 08:50Buy short83.7060.0071.7¢
11-13 07:50Buy longpair10.252.9829.1¢
11-13 05:50Buy longpair7.622.2028.9¢
11-13 04:50Buy short21.2015.0571.0¢
11-13 03:50Buy longpair20.195.8629.0¢
11-13 03:50Buy short33.9024.0170.8¢
11-13 02:50Buy longpair38.3811.1829.1¢
11-12 18:50Buy longpair17.765.0728.6¢
11-12 17:50Buy short36.5926.0771.3¢

A trade marked pair is one leg of a simulated spread trade: the other leg is in a real-asset contract that follows this index.

Settlement

KORD is a US station, so this contract settles on the NWS daily climate report (CLI) of each of its 7 days: the index is the sum built from the high and low the National Weather Service prints. The local forecast office issues each report after local midnight, normally within one to three hours, and the contract settles one day after the last report is issued - about 12-01 08:00. A corrected report replaces the earlier one and the day runs again from it. If any day has no final report three days after the period ends, the contract is void and every position is refunded at cost. NWS CLI Watch ↗

Contract specification

Symbol
GDD-KORD-26W48
Index
Growing degree days (GDD), in °C-days
Formula
(high + low) / 2 - 10 with both held to 10..30 °C, summed over the period
Station
KORD · Chicago
Period
Week 48 · Nov 23 - Nov 29 · 7 local days, 2026-11-23 to 2026-11-29
Band
0 to 29
Payoff
Long: (index - 0) / 29 sUSDT per share, held to 0..1. Short: 1 minus that.
Point value
0.0345 sUSDT per share per index point
Trading closes
2026-11-29 06:00 UTC
Settles
One day after the NWS climate report for the last day is issued
Settlement source
The NWS daily climate report (CLI) of each day, as carried by the Weather Market oracle
Hedges
Agriculture - Corn, Soybeans (the exposure it hedges; this contract settles on the index)
Trade GDD-KORD-26W48

Long gains if GDD finishes above the level you pay for.

Virtual sUSDT only. No monetary value.

Rules in short
  • Long gains when the index finishes higher, short when it finishes lower. A long and a short share together always pay 1 sUSDT.
  • Outside the band 0 to 29 the contract pays as if the index had finished on the edge.
  • You pay in full when you buy. What you paid is the most you can lose: no margin, no liquidation.
  • You can sell back to the market maker at any time before trading closes, when the last day of the period begins.
  • A US station: the index is built from the high and low in the NWS daily climate report of each day, and the contract settles a day after the last of those reports is issued. Void, with every position refunded at cost, if any day has no final report three days after the period ends.
Full rules →