Authentication¶

The OpenWeather API requires an API key for all requests.
This key identifies you and ensures fair usage across the platform.

Obtaining an API Key¶

Create a free account at OpenWeather.
Log in to your dashboard.
Generate a new API key.
Copy and securely store your key (you’ll need it for every request).

How to Use the API Key¶

The API key must be included as the appid query parameter in each request.

Example

curl "https://api.openweathermap.org/data/2.5/weather?q=London&appid=YOUR_API_KEY"

Using Units¶

You can specify the unit system with the units parameter:

standard (default, Kelvin)
metric (Celsius)
imperial (Fahrenheit)

Example

curl "https://api.openweathermap.org/data/2.5/weather?q=London&units=metric&appid=YOUR_API_KEY"

Example Response (sample)¶

{
  "coord": { "lon": 36.8219, "lat": -1.2921 },
  "weather": [
    { "main": "Clear", "description": "clear sky" }
  ],
  "main": {
    "temp": 26.5,
    "humidity": 54
  },
  "name": "London"
}

Best Practices¶

Do not share your key in public repositories or client-side code.
Rotate keys periodically for security.
Monitor usage in your OpenWeather dashboard.
Use environment variables to store your API key in projects.

FAQs¶

Q: Can I pass the key as a header instead of query param? A: No. The OpenWeather API only supports the appid query parameter.

Q: Can I have multiple API keys? A: Yes, you can generate more than one key in your dashboard.

Q: What if I lose my API key? A: You can revoke and generate a new one from your OpenWeather account.