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Open-Meteo Historical Archive API

Free historical weather API with no key: hourly and daily weather for any location worldwide going back to 1940, from ERA5 reanalysis data. Tested example.

No API key requiredHTTPSFree tier

Endpoint tested and returned HTTP 200 on 20 Aug 2026

What is the Open-Meteo Historical Archive API?

The Open-Meteo Historical Weather API is a free, key-free API providing hourly and daily weather records for any location worldwide going back to 1940, based on ERA5 and other reanalysis datasets.

Historical weather is normally expensive — commercial providers charge substantially for archive access. This endpoint gives eight decades of hourly global data for free, drawn from ECMWF's ERA5 reanalysis.

Reanalysis is worth understanding: rather than raw station readings, it is a physical model reconstruction assimilating observations, which means consistent global coverage including oceans and places that never had a weather station. The tradeoff is that it is a modelled estimate, not a direct measurement.

Quick facts

Base URL
https://archive-api.open-meteo.com/v1/archive
Authentication
No API key required.
Rate limit
Shares the Open-Meteo fair-use policy — roughly 10,000 requests per day.
Pricing
Free including commercial use below the daily limit.
CORS
Not enabled — call it from your server
Official docs
Read the docs

How to use the Open-Meteo Historical Archive API

Every request below was executed against the live API on 20 Aug 2026, and the response shown is the real body it returned — not an illustration.

1. Fetch historical daily weather

GET https://archive-api.open-meteo.com/v1/archive?latitude=52.52&longitude=13.41&start_date=2026-01-01&end_date=2026-01-02&daily=temperature_2m_max

curl
curl 'https://archive-api.open-meteo.com/v1/archive?latitude=52.52&longitude=13.41&start_date=2026-01-01&end_date=2026-01-02&daily=temperature_2m_max'
JavaScript (fetch)
const res = await fetch("https://archive-api.open-meteo.com/v1/archive?latitude=52.52&longitude=13.41&start_date=2026-01-01&end_date=2026-01-02&daily=temperature_2m_max");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);
Python (requests)
import requests

res = requests.get("https://archive-api.open-meteo.com/v1/archive?latitude=52.52&longitude=13.41&start_date=2026-01-01&end_date=2026-01-02&daily=temperature_2m_max", timeout=20)
res.raise_for_status()
print(res.json())
Response — HTTP 200
{
  "latitude": 52.54833,
  "longitude": 13.407822,
  "generationtime_ms": 1.4096498489379883,
  "utc_offset_seconds": 0,
  "timezone": "GMT",
  "timezone_abbreviation": "GMT",
  "elevation": 38.0,
  "daily_units": {
    "time": "iso8601",
    "temperature_2m_max": "°C"
  },
  "daily": {
    "time": [
      "2026-01-01",
      "2026-01-02"
    ],
    "temperature_2m_max": [
      3.0,
      2.5
    ]
  }
}

Parameters

ParameterTypeRequiredDescription
latitude / longitudefloatRequiredCoordinates. 52.52
start_date / end_datestringRequiredDate range as YYYY-MM-DD, from 1940 onwards. 2026-01-01
dailystringOptionalDaily aggregates such as temperature_2m_max. temperature_2m_max
hourlystringOptionalHourly variables — large responses over long ranges. temperature_2m
timezonestringOptionalIANA timezone or auto. auto

Response fields

latitude / longitudenumber
The model grid point used, snapped from your request.
daily.timearray
Dates for each daily value.
daily.temperature_2m_maxarray
Daily maximum temperatures.
hourly.time / hourly.<variable>array
Parallel arrays of timestamps and values.
daily_units / hourly_unitsobject
Units for each variable.
elevationnumber
Elevation of the grid cell.

What you can build with the Open-Meteo Historical Archive API

  • Analyse long-term climate trends for a location
  • Correlate historical weather with business or agricultural data
  • Backfill weather context into analytics
  • Research extreme weather events without paying for archive access

Common errors and how to fix them

Enormous response

Hourly data over years produces huge arrays.

Fix: Use daily aggregates unless you genuinely need hourly, and split long ranges.

Recent dates missing

Reanalysis data lags real time by around five days.

Fix: Use the forecast API for recent and current conditions.

Values differ from a local station

Reanalysis is modelled, not measured.

Fix: It is a physically consistent estimate for a grid cell, not a station reading — expect small differences.

Open-Meteo Historical Archive API — frequently asked questions

Is there a free historical weather API?

Yes. The Open-Meteo Historical Weather API provides hourly global data back to 1940 with no API key, which commercial providers normally charge substantially for.

What is reanalysis data?

A physical model reconstruction that assimilates historical observations, producing consistent global coverage including oceans and regions with no weather stations. It is a modelled estimate rather than a direct measurement.

Why is there no data for last week?

Reanalysis processing lags real time by around five days. Use the standard Open-Meteo forecast API for recent and current conditions.

How far back does it go?

To 1940, giving over eight decades of hourly data — enough for genuine climate trend analysis.

Tools that pair with this API

Alternatives to Open-Meteo Historical Archive API

If Open-Meteo Historical Archive does not fit, these weather apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.

APIWhat it doesAuthCORSLast verified
Open-MeteoFree weather forecast API with no API key and no signup. Hourly and daily forecasts worldwide, free for commercial use. Working curl example and live response.No keyYes19 Aug 2026
Open-Meteo Air QualityFree air quality API with no key: PM2.5, PM10, ozone, nitrogen dioxide, European and US AQI plus pollen forecasts worldwide. Tested curl example included.No keyYes19 Aug 2026
wttr.inwttr.in is a free console-oriented weather API with no key. Get weather as plain text, ASCII art, PNG or full JSON with one curl command. Live example included.No keyYes19 Aug 2026
Open-Meteo GeocodingFree geocoding API with no key: convert a city or place name into latitude and longitude, with population, country and timezone. Tested curl example and live JSON.No keyYes19 Aug 2026
Hong Kong ObservatoryFree Hong Kong weather API with no key: current readings by district, rainfall, warnings and forecasts from the territory's official meteorological service. Tested example included.No keyYes21 Aug 2026
IPMA (Portugal)Free Portuguese weather API with no key: five-day city forecasts from the national meteorological institute, plus seismic and warning datasets. Tested example included.No keyYes21 Aug 2026
All Weather APIs

Open-Meteo Historical Archive is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 20 Aug 2026; always check the official documentation before relying on this API in production, as terms and limits can change.