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OpenEnergy · Heating demandWeather index future · simulation

New York heating degree days · November 2026

Heating degree days at KJFK · 30 local days, 2026-11-01 to 2026-11-30 · trading closes 11-30 05:00 (16 d)

Market index
199.3°C-days
Long 62.1¢ · Short 37.9¢ per share
Model fair
206.9 ± 22.6
priced 23 min ago
Edge
+7.6
fair minus market
Volume
526
18 traders
Open interest
733 / 259
long / short shares
100 · long pays 0long pays 1 · 260
Market 199.3Model fair 206.9On the record 49.1 (12 of 30 days) - the index cannot finish below this
Listed at 180.8 · quoted by a market maker, no order book · one share moves 0.0063 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 HDD 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
NGAS-KJFK-NOV26Natural gas110.46long 60¢113.69

How the index builds, day by day

Final recordForecastBeyond 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.

0102011-0111-0411-0711-1011-1311-1611-1911-2211-2511-28
Day-by-day table
DaySourceHighLowHDDRunning total
Sun, Nov 1Final record57.9°F42.1°F8.08.0
Mon, Nov 2Final record64.9°F46.0°F5.012.9
Tue, Nov 3Final record66.0°F48.0°F4.117.1
Wed, Nov 4Final record68.0°F53.1°F2.219.2
Thu, Nov 5Final record68.0°F61.0°F0.019.2
Fri, Nov 6Final record66.9°F60.1°F0.519.7
Sat, Nov 7Final record64.9°F48.9°F4.123.8
Sun, Nov 8Final record62.1°F48.9°F5.028.8
Mon, Nov 9Final record61.0°F48.9°F5.234.0
Tue, Nov 10Final record63.0°F48.0°F5.039.0
Wed, Nov 11Final record63.0°F48.9°F4.743.6
Thu, Nov 12Final record61.0°F48.0°F5.549.1
Fri, Nov 13Forecast48.7°F35.8°F12.3 ± 1.861.4
Sat, Nov 14Forecast44.1°F33.4°F14.3 ± 1.875.7
Sun, Nov 15Forecast50.5°F36.5°F11.6 ± 1.887.3
Mon, Nov 16Forecast53.8°F39.4°F9.9 ± 1.997.2
Tue, Nov 17Forecast56.7°F40.1°F8.9 ± 2.0106.1
Wed, Nov 18Forecast59.2°F43.3°F7.3 ± 2.2113.4
Thu, Nov 19Forecast61.2°F46.2°F6.0 ± 2.4119.4
Fri, Nov 20Forecast63.5°F48.0°F4.8 ± 2.5124.2
Sat, Nov 21Forecast58.6°F47.7°F6.3 ± 2.8130.5
Sun, Nov 22Forecast60.3°F51.8°F4.7 ± 2.9135.2
Mon, Nov 23Forecast61.5°F55.0°F3.6 ± 2.9138.9
Tue, Nov 24Forecast60.8°F55.4°F3.8 ± 3.0142.6
Wed, Nov 25Forecast59.0°F36.7°F9.2 ± 3.7151.8
Thu, Nov 26Forecast43.0°F32.4°F14.8 ± 3.9166.7
Fri, Nov 27Forecast47.5°F34.5°F13.0 ± 4.2179.7
Sat, Nov 28Beyond the forecast52.3°F43.9°F9.1 ± 4.4188.8
Sun, Nov 29Beyond the forecast52.3°F43.9°F9.1 ± 4.4197.8
Mon, Nov 30Beyond the forecast52.3°F43.9°F9.1 ± 4.4206.9

Market index path

one step per trade · dashed line: model fair now
168.9192.7216.5

Recent trades

TimeTradeSharesAmountAvg price
11-13 19:50Buy long52.2832.1361.5¢
11-13 18:50Buy long40.4924.4460.4¢
11-13 17:50Buy long102.3360.0058.6¢
11-13 16:50Buy long87.1149.0656.3¢
11-13 14:50Buy longpair28.7715.7954.9¢
11-13 12:50Buy longpair20.6711.2254.3¢
11-13 05:50Buy long83.7544.3753.0¢
11-13 04:50Buy longpair7.683.9851.8¢
11-13 02:50Buy long47.2724.1851.2¢
11-13 01:50Buy shortpair17.908.8149.2¢
11-13 01:50Buy long75.6037.8550.1¢
11-13 00:50Buy short29.8215.0650.5¢
11-12 21:50Buy short51.8525.6649.5¢
11-12 20:50Buy longpair13.436.8551.0¢
11-12 19:50Buy longpair12.206.1850.7¢

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

KJFK is a US station, so this contract settles on the NWS daily climate report (CLI) of each of its 30 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 12-02 07:00. 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
HDD-KJFK-NOV26
Index
Heating degree days (HDD), in °C-days
Formula
max(0, 18 - (high + low) / 2), summed over the period
Station
KJFK · New York
Period
November 2026 · 30 local days, 2026-11-01 to 2026-11-30
Band
100 to 260
Payoff
Long: (index - 100) / 160 sUSDT per share, held to 0..1. Short: 1 minus that.
Point value
0.0063 sUSDT per share per index point
Trading closes
2026-11-30 05:00 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
Energy - Natural gas, Heating oil, District heat (the exposure it hedges; this contract settles on the index)
Trade HDD-KJFK-NOV26

Long gains if HDD 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 100 to 260 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 →