Public API
Use the Starnberger See API to enhance your app, website, dashboard, or local product with current water temperature measurements and predictions.
The API returns simple JSON over HTTPS, so it works well for mobile apps, websites, server-side integrations, displays, and automation tools.
Endpoints are public and available without API keys. Please cache responsibly and keep request volume reasonable for user-facing integrations.
Practical data for products around the lake.
Lake condition widgets
Tourism, hotel, and event websites
Bathing, sailing, rowing, and SUP apps
Local dashboards and smart-home displays
All responses use JSON. Temperatures are °C.
Offsetless water-measurement and forecast timestamps are Germany local time (Europe/Berlin), matching the NID Bayern source data.
Returns the newest measured water temperature for Starnberger See. datetime is Germany local time (Europe/Berlin), matching the NID Bayern source table.
Request
curl https://starnberger.app/api/v1/latestResponse
{
"temperature": 18.7,
"datetime": "2026-04-29T10:15:00"
}Returns the latest measurements in chronological order. Use limit to choose up to 128 entries. datetime is Germany local time (Europe/Berlin).
Request
curl https://starnberger.app/api/v1/entries?limit=24Response
[
{
"temperature": 18.4,
"datetime": "2026-04-29T08:15:00"
},
{
"temperature": 18.7,
"datetime": "2026-04-29T10:15:00"
}
]Returns the next 12 predicted lake-temperature hours with 50 and 90 percent prediction intervals. base_time and forecast.time are Europe/Berlin wall-clock timestamps without an offset.
Request
curl https://starnberger.app/api/v1/forecastResponse
{
"base_time": "2026-05-31T11:00:00",
"lake_temp_now": 18.4,
"generated_at": "2026-05-31T10:38:44Z",
"forecast": [
{
"h": 1,
"time": "2026-05-31T12:00:00",
"temp": 18.7,
"p5": 18.4,
"p95": 19.0,
"p25": 18.6,
"p75": 18.8
}
],
"mean_skill_pct": 36.0,
"model": "LightGBM (L1 central + CQR quantiles) on temperature deltas"
}The API is intentionally small and stable. Use the OpenAPI file for machine-readable schema details, and handle occasional upstream data gaps gracefully.
limit on /api/v1/entries defaults to 24 when omitted and must otherwise be a positive integer up to 128.
Error responses use { "error": "Message" } with appropriate HTTP status codes such as 400, 404, 429, or 500.
API responses include public CORS headers and short edge cache headers. Clients should still cache locally where practical.
Endpoints return standard RateLimit headers. Excessive traffic receives a 429 response.
const response = await fetch('https://starnberger.app/api/v1/latest');
const latest = await response.json();