omni-weather-forecast-apis 0.1.0

Universal weather forecast aggregation library with a typed normalized schema.

omni-weather-forecast-apis

Async Python library that fans out forecast requests across multiple weather providers and normalizes the results into one typed Pydantic schema. It preserves provider-native cadence and time boundaries while converting units and condition codes into a common representation.

Features

• Multi-provider fan-out with async orchestration and partial-failure tolerance
• Typed normalized schema — common Pydantic models for minutely, hourly, daily, and alert data
• Plugin architecture — 13 providers with typed per-provider config validation
• Rate limiting — global concurrency and RPS limits with per-provider overrides
• CLI — loads a TOML config, queries providers, and persists normalized output to SQLite

Supported Providers

Provider	Plugin ID	API Key	Notes
Open-Meteo	open_meteo	Optional	Free tier; multiple forecast models
MET Norway	met_norway	No	Requires user_agent identification
NWS / NOAA	nws	No	US coverage only; requires user_agent
OpenWeather	openweather	Yes
WeatherAPI	weatherapi	Yes
Tomorrow.io	tomorrow_io	Yes
Visual Crossing	visual_crossing	Yes
Weatherbit	weatherbit	Yes
Meteosource	meteosource	Yes
Pirate Weather	pirate_weather	Yes	Dark Sky-compatible API
Stormglass	stormglass	Yes	Hourly only; multi-model
Weather Unlocked	weather_unlocked	Yes	Requires app_id + app_key
Google Weather	google_weather	—	Placeholder; currently unavailable

Quick Start

# 1. Install
uv sync

# 2. Create a minimal config (Open-Meteo and MET Norway require no API keys)
cat > config.toml << 'EOF'
[[providers]]
plugin_id = "open_meteo"
config = { models = ["best_match"] }

[[providers]]
plugin_id = "met_norway"
config = { user_agent = "MyApp/1.0 [e-mail]" }
EOF

# 3. Run a forecast
uv run omni-weather \
  --config ./config.toml \
  --lat 40.7128 \
  --lon -74.0060 \
  --sqlite ./forecasts.sqlite

Installation

uv sync

How It Works

1. Fan-out — A ForecastRequest is dispatched concurrently to every enabled provider using async tasks, bounded by configurable concurrency and rate limits.
2. Normalize — Each provider plugin converts its native response into the common SourceForecast schema, translating units (e.g. Fahrenheit to Celsius, mph to m/s) and mapping provider-specific condition codes to a shared WeatherCondition enum.
3. Aggregate — Results are collected into a single ForecastResponse. Providers that succeed return ProviderSuccess with their forecasts; providers that fail return ProviderError with a typed error code. The response always completes, even if some providers fail.

Configuration

The client and CLI both use a TOML configuration file that matches OmniWeatherConfig.

default_timeout_ms = 10000

[rate_limiting]
max_in_flight = 10
max_requests_per_second = 20

[[providers]]
plugin_id = "open_meteo"
enabled = true
config = { models = ["best_match", "ecmwf_ifs025"] }

[[providers]]
plugin_id = "met_norway"
enabled = true
config = { user_agent = "MyApp/1.0 [e-mail]", variant = "complete" }

[[providers]]
plugin_id = "openweather"
enabled = true
config = { api_key = "ow-...", units = "metric" }
rate_limit_rps = 5
timeout_ms = 8000

Library Usage

import asyncio

from omni_weather_forecast_apis import (
    ForecastRequest,
    Granularity,
    OmniWeatherConfig,
    ProviderError,
    ProviderRegistration,
    ProviderId,
    ProviderSuccess,
    create_omni_weather,
)


async def main() -> None:
    config = OmniWeatherConfig(
        providers=[
            ProviderRegistration(
                plugin_id=ProviderId.OPEN_METEO,
                config={"models": ["best_match"]},
            ),
            ProviderRegistration(
                plugin_id=ProviderId.MET_NORWAY,
                config={"user_agent": "MyApp/1.0 [e-mail]"},
            ),
        ],
    )

    async with await create_omni_weather(config) as client:
        response = await client.forecast(
            ForecastRequest(
                latitude=34.2484,
                longitude=-117.1931,
                granularity=[Granularity.HOURLY, Granularity.DAILY],
            ),
        )
        print(response.summary)
        # ForecastResponseSummary(total=2, succeeded=2, failed=0)

        for result in response.results:
            match result:
                case ProviderSuccess(provider=pid, forecasts=forecasts):
                    for fc in forecasts:
                        for pt in fc.hourly:
                            print(f"{pid} {pt.timestamp}: {pt.temperature}°C, {pt.condition}")
                case ProviderError(provider=pid, error=err):
                    print(f"{pid} failed: {err.code} — {err.message}")


asyncio.run(main())

Example output:

ProviderId.OPEN_METEO 2026-03-13 18:00:00+00:00: 12.3°C, WeatherCondition.PARTLY_CLOUDY
ProviderId.OPEN_METEO 2026-03-13 19:00:00+00:00: 11.8°C, WeatherCondition.OVERCAST
ProviderId.MET_NORWAY 2026-03-13 18:00:00+00:00: 12.1°C, WeatherCondition.RAIN
...

CLI Usage

uv run omni-weather \
  --config ./config.toml \
  --lat 34.2484 \
  --lon -117.1931 \
  --sqlite ./forecasts.sqlite

# Query only specific providers
uv run omni-weather \
  --config ./config.toml \
  --lat 34.2484 \
  --lon -117.1931 \
  --sqlite ./forecasts.sqlite \
  --provider open_meteo \
  --provider nws \
  --granularity hourly

Flag	Required	Default	Description
--config PATH	Yes	—	Path to TOML configuration file
--lat FLOAT	Yes	—	Latitude (-90 to 90)
--lon FLOAT	Yes	—	Longitude (-180 to 180)
--sqlite PATH	Yes	—	SQLite database output path
--provider ID	No	all enabled	Restrict to specific provider(s); repeatable
--granularity GRAN	No	hourly + daily	minutely, hourly, or daily; repeatable
--language LANG	No	en	Provider language preference
--include-raw	No	off	Persist raw provider payloads
--timeout-ms MS	No	config value	Override the default timeout; provider-specific timeouts still take precedence

Exit codes: 0 all providers succeeded, 1 at least one provider failed, 2 invalid arguments or configuration/load error.

Partial Failures

The library is designed for partial-failure tolerance. When some providers fail (network errors, rate limits, auth issues), the response still completes with results from the providers that succeeded.

Each entry in response.results is either a ProviderSuccess or ProviderError, distinguished by the status field. The response.summary provides counts at a glance:

response.summary
# ForecastResponseSummary(total=3, succeeded=2, failed=1)

ProviderError includes a typed error.code (AUTH_FAILED, RATE_LIMITED, TIMEOUT, NETWORK, PARSE, NOT_AVAILABLE, UNKNOWN), a human-readable error.message, the error.http_status when available, and error.latency_ms for how long the request ran before failing.

The CLI reflects this in exit codes: 0 means all providers succeeded, 1 means at least one failed (but partial results are still written to SQLite).

Normalized Schema

All provider responses are normalized into a common set of Pydantic models. Units are standardized: temperatures in °C, wind speeds in m/s, pressure in hPa, precipitation in mm, visibility in km.

WeatherDataPoint (hourly)

Field	Type	Unit
temperature, apparent_temperature, dew_point	float | None	°C
humidity	float | None	% (0-100)
wind_speed, wind_gust	float | None	m/s
wind_direction	float | None	degrees
pressure_sea, pressure_surface	float | None	hPa
precipitation, rain, snow, snow_depth	float | None	mm
precipitation_probability	float | None	0-1
cloud_cover, cloud_cover_low, cloud_cover_mid, cloud_cover_high	float | None	%
visibility	float | None	km
uv_index	float | None	0-11+
solar_radiation_ghi, solar_radiation_dni, solar_radiation_dhi	float | None	W/m²
condition	WeatherCondition | None	enum
is_day	bool | None

DailyDataPoint

Field	Type	Unit
date	date
temperature_max, temperature_min	float | None	°C
apparent_temperature_max, apparent_temperature_min	float | None	°C
wind_speed_max, wind_gust_max	float | None	m/s
precipitation_sum, rain_sum, snowfall_sum	float | None	mm
precipitation_probability_max	float | None	0-1
cloud_cover_mean	float | None	%
humidity_mean	float | None	%
uv_index_max	float | None	0-11+
sunrise, sunset, moonrise, moonset	datetime | None	UTC
moon_phase	float | None	0-1
daylight_duration	float | None	seconds
condition	WeatherCondition | None	enum
summary	str | None

MinutelyDataPoint

Field	Type	Unit
precipitation_intensity	float | None	mm/h
precipitation_probability	float | None	0-1

WeatherAlert

Field	Type
sender_name	str
event	str
start, end	datetime (UTC)
description	str
severity	EXTREME | SEVERE | MODERATE | MINOR | UNKNOWN
url	str | None

WeatherCondition enum

CLEAR, MOSTLY_CLEAR, PARTLY_CLOUDY, MOSTLY_CLOUDY, OVERCAST, FOG, DRIZZLE, LIGHT_RAIN, RAIN, HEAVY_RAIN, FREEZING_RAIN, LIGHT_SNOW, SNOW, HEAVY_SNOW, SLEET, HAIL, THUNDERSTORM, THUNDERSTORM_RAIN, THUNDERSTORM_HEAVY, DUST, SAND, SMOKE, HAZE, TORNADO, HURRICANE, UNKNOWN

Provider Configuration Reference

Each provider accepts a typed config dict. Required fields are marked with bold.

Provider	Config Keys
open_meteo	api_key?, models (default: ["best_match"]), extra_hourly_vars?, extra_daily_vars?
met_norway	user_agent, altitude?, variant ("compact" | "complete", default: "complete")
nws	user_agent, grid_override? ({office, grid_x, grid_y})
openweather	api_key, exclude?, units ("standard" | "metric" | "imperial", default: "metric")
weatherapi	api_key, days (1-14, default: 7), aqi (default: false), alerts (default: true)
tomorrow_io	api_key, fields?
visual_crossing	api_key, include (default: "hours,days,alerts")
weatherbit	api_key, hours (1-240, default: 48), units ("M" | "S" | "I", default: "M")
meteosource	api_key, sections (default: ["current", "hourly", "daily"])
pirate_weather	api_key, extend_hourly (default: false), version ("1" | "2", default: "2")
stormglass	api_key, sources (default: ["sg"]), params (list of weather variables)
weather_unlocked	app_id, app_key, lang?
google_weather	api_key? (placeholder, currently unavailable)

SQLite Output

The CLI creates a normalized database with these tables:

Table	Contents
forecast_runs	Request metadata per invocation
provider_results	One row per provider outcome (success or error)
source_forecasts	One row per model/source forecast within a provider
minutely_points	Precipitation intensity at minute intervals
hourly_points	Normalized hourly forecast rows
daily_points	Normalized daily summary rows
alerts	Weather alerts and warnings

Development

# Lint and type-check
uv run black src
uv run ruff check src --fix
uv run pyrefly check src
uv run ty check src

# Complexity and tests
uv run lizard -Eduplicate src
uv run pytest tests/

License

Apache 2.0