Overview
7Timer! is a free weather forecast API originally built for astronomers who need clear-sky predictions. It provides multi-day forecasts including cloud cover, wind, seeing conditions, and more for any latitude and longitude on Earth. No API key or registration is required, making it one of the easiest weather APIs to start using.
Beginner Tip
Provide lat and lon as decimal coordinates and choose a product like ASTRO for astronomy or CIVIL for general weather; the API returns XML or JSON depending on the output parameter you set. Because no authentication is needed, you can test your first request directly in a browser.
Measurement Record
What actually happened when we called this API from our own infrastructure. Every value below was recorded by the request, not copied from the provider's documentation.
- Request
- GET http://www.7timer.info/bin/api.pl?lon=-0.1278&lat=51.5074&product=civil&output=json
- Result
- HTTP 200 · text/plain · 15,122 bytes · compressed
- Response time
- 317 ms (median of 3) · fastest 310 ms
- Browser CORS
- No Access-Control-Allow-Origin header — call it from a server, not the browser
- Served by
- Apache/2.4.68 (Debian)
- Recorded
- 2026-08-10
Fields Returned
Top-level fields present in the response we captured, with the type and value we actually received.
| Field | Type | Value received |
|---|---|---|
| product | string | civil |
| init | string | 2026081012 |
| dataseries | array | [1 item] |
Captured Response
Captured from a real request to http://www.7timer.info/bin/api.pl?lon=-0.1278&lat=51.5074&product=civil&output=json on 2026-08-10. Long arrays and nested objects are truncated to keep the shape readable.
{
"product": "civil",
"init": "2026081012",
"dataseries": [
{
"timepoint": 3,
"cloudcover": 9,
"lifted_index": 10,
"prec_type": "none",
"prec_amount": 0,
"temp2m": 26,
"rh2m": "33%",
"wind10m": {
"…": "(2 more fields)"
},
"weather": "cloudyday"
}
]
} Field Reference
product The forecast product type requested, such as civil or astro. init The initialization time of the forecast model in UTC format. dataseries Array of forecast time steps, each covering a 3-hour interval. Implementation Example
Calls a real endpoint of this API. Replace any placeholder credentials with your own key.
const url = "http://www.7timer.info/";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
Common Errors & Troubleshooting
Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.
Measured Score Breakdown
Live HTTP request to the API endpoint
Fully tested on Aug 10, 2026
Technical Specifications
Related Tags
Alternatives to 7Timer!
Technical alternatives for different use cases.
Simple astronomical and weather forecast, no auth required
Detailed current conditions and historical data
Astronomy-related weather forecasts
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