Polymarket Weather Trading Bot

Node.js / TypeScript trading automation for Polymarket daily temperature markets. The bot combines National Weather Service (NWS) forecast data with Polymarket CLOB pricing: it maps a city’s forecast max temperature to a market bucket, then supports read-only signals, paper trading in a local JSON ledger, or live orders.

Overview

The bot scans configured cities, finds the matching temperature range for the forecast, compares the YES price to entry and exit thresholds, and either prints signals, updates simulation.json, or posts real CLOB orders depending on the selected npm script. Runtime configuration is driven by .env (not config.json at execution time for the main flows described here).

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https://github.com/user-attachments/assets/a4940d4d-be6e-478b-b2ba-1c84ecaa5c74

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https://github.com/user-attachments/assets/70ef0168-1671-4057-bb4b-c3435016732b

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Key features

• NWS-driven: Uses NWS observations and forecast data to estimate daily max temperature.
• Bucket matching: Picks the Polymarket outcome range that contains the forecast temperature.
• Three execution modes: Signal-only, paper (simulated PnL in simulation.json), and live CLOB trading.
• Proxy wallet support: MetaMask signer with Polymarket proxy funder when USE_PROXY_WALLET and SIGNATURE_TYPE=2 are set.
• Recurring runs: Optional --interval for scheduled live execution (see npm run trade).

Architecture

Technology stack

• Runtime: Node.js, TypeScript
• Chain: Polygon
• Execution: Polymarket CLOB V2 via @polymarket/clob-client-v2
• Data: NWS APIs for location-specific weather (see src/nws.ts and related modules)
• Config: .env for secrets and strategy parameters; config.json is not used for runtime config in the primary flows documented below

System flow

NWS forecast + city list → Polymarket event for date
→ Map temp to bucket → Compare YES to ENTRY_THRESHOLD / EXIT_THRESHOLD
→ Signal | Update simulation | Place order

Installation

Prerequisites

• Node.js 18+ and npm
• A wallet with USDC on Polymarket for live mode, with keys from environment only
• NWS and Polymarket API reachability

Setup

1. Clone the repository and enter the directory

bash git clone <repository-url> cd Polymarket-Weather-Bot

1. Install dependencies

bash npm install

1. Configure environment

bash cp .env.sample .env

Edit .env. Example:

env POLYMARKET_PRIVATE_KEY=0xYOUR_METAMASK_PRIVATE_KEY POLYMARKET_PROXY_WALLET_ADDRESS=0xYOUR_POLYMARKET_PROXY_WALLET USE_PROXY_WALLET=true SIGNATURE_TYPE=2 ENTRY_THRESHOLD=0.15 EXIT_THRESHOLD=0.45 MAX_TRADES_PER_RUN=5 MIN_HOURS_TO_RESOLUTION=2 LOCATIONS="nyc,chicago,miami,dallas,seattle,atlanta"

1. Credentials

For live trading, confirm the private key, proxy address, USDC balance, and Polymarket trading allowance. Test with signal and paper before execute / trade.

Configuration

Environment variables

Variable	Type	Default	Description
POLYMARKET_PRIVATE_KEY	string	required for live	MetaMask (or EOA) private key
POLYMARKET_PROXY_WALLET_ADDRESS	string	required for live with proxy	Polymarket proxy funder from account settings
USE_PROXY_WALLET	boolean	false (see code)	When true, use proxy; typically pair with SIGNATURE_TYPE=2
SIGNATURE_TYPE	0 | 1 | 2	derived	0 EOA, 1 Polymarket proxy, 2 Gnosis Safe / browser flow
ENTRY_THRESHOLD	number	0.15	Buy when matching bucket YES is below this
EXIT_THRESHOLD	number	0.45	Exit when held YES is above this
MAX_TRADES_PER_RUN	number	5	Cap entries per run
MIN_HOURS_TO_RESOLUTION	number	2	Skip markets resolving sooner than this
LOCATIONS	string	multi-city	Comma-separated city keys to scan

Supported cities (typical)

nyc, chicago, miami, dallas, seattle, atlanta (see LOCATIONS and source for the authoritative list).

Usage

Build and run modes

Mode	Command	Real orders?
Signal	npm run signal	No
Paper	npm run paper	No (writes simulation.json)
One-shot live	npm run execute	Yes
Live on interval	npm run trade	Yes (30-minute interval)

npm run signal
npm run paper
npm run execute
npm run trade

Other scripts

npm run positions   # list open (paper) positions
npm run reset       # reset simulation state

Technical details

Entry logic (high level)

1. Load forecast max temperature for each configured city and resolution window.
2. Find the Polymarket market whose temperature bucket contains that value.
3. If YES is below ENTRY_THRESHOLD and other guards pass (horizon, max trades, existing position), open.
4. If already holding, exit when YES reaches EXIT_THRESHOLD (or per implementation in src/strategy.ts).

State

• Paper / simulation: simulation.json tracks virtual balance and open legs (file is gitignored).

Project structure

Polymarket-Weather-Bot/
├── public/
│   ├── weather.png            # README / demo still (add asset)
│   └── weather.mp4          # optional local demo
├── src/
│   ├── index.ts
│   ├── config.ts
│   ├── nws.ts
│   ├── polymarket.ts
│   ├── clob.ts
│   ├── strategy.ts
│   ├── simState.ts
│   ├── walletBalance.ts
│   ├── parsing.ts
│   ├── time.ts
│   └── colors.ts
├── dist/                      # tsc output
├── simulation.json            # local paper state (gitignored)
├── package.json
├── tsconfig.json
├── .env.sample
└── README.md

API integration

CLOB

Orders use @polymarket/clob-client-v2 with the configured signer and, when used, the Polymarket proxy as funder.

NWS

Forecast and related endpoints are accessed from src/nws.ts and supporting modules; respect NWS terms of use and rate limits.

Monitoring and logging

• Console output with chalk styling for readability.
• Paper mode: inspect simulation.json and npm run positions.

Change history

Worth tracking for this project:

1. Mode gating: Always validate signal → paper → execute before scaling size.
2. simulation state: Regenerated locally; not suitable for commit.

Risk considerations

1. Forecast error: NWS data can disagree with the resolution source Polymarket uses.
2. Liquidity and slippage: YES/NO books may be thin.
3. Time to resolution: Short horizons increase sensitivity to price moves.
4. Live credentials: A mistake in POLYMARKET_* or allowance can still move real funds.

Operational suggestions: Run signal and paper first, use small size in execute, and monitor until you trust the end-to-end path.

Development

npm run build
npm run signal

Support

Use repository issues for bugs and feature requests. For CLOB and proxy wallet behavior, refer to Polymarket’s official documentation.

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Disclaimer: This software is provided as-is, without warranty. Prediction markets and digital assets involve substantial risk of loss. Use only capital you can afford to lose and comply with applicable laws in your jurisdiction.

Version: 1.0.0
Last updated: April 2026