# NAME

Weather::Meteo - Interface to [https://open-meteo.com](https://open-meteo.com) for historical weather data

# VERSION

Version 0.11

# SYNOPSIS

The `Weather::Meteo` module provides an interface to the Open-Meteo API for retrieving historical weather data from 1940.
It allows users to fetch weather information by specifying latitude, longitude, and a date.
The module supports object-oriented usage and allows customization of the HTTP user agent.

      use Weather::Meteo;

      my $meteo = Weather::Meteo->new();
      my $weather = $meteo->weather({ latitude => 0.1, longitude => 0.2, date => '2022-12-25' });

- Caching

    Identical requests are cached (using [CHI](https://metacpan.org/pod/CHI) or a user-supplied caching object),
    reducing the number of HTTP requests to the API and speeding up repeated queries.

    This module leverages [CHI](https://metacpan.org/pod/CHI) for caching geocoding responses.
    When a geocode request is made,
    a cache key is constructed from the request.
    If a cached response exists,
    it is returned immediately,
    avoiding unnecessary API calls.

- Rate-Limiting

    A minimum interval between successive API calls can be enforced to ensure that the API is not overwhelmed and to comply with any request throttling requirements.

    Rate-limiting is implemented using [Time::HiRes](https://metacpan.org/pod/Time%3A%3AHiRes).
    A minimum interval between API
    calls can be specified via the `min_interval` parameter in the constructor.
    Before making an API call,
    the module checks how much time has elapsed since the
    last request and,
    if necessary,
    sleeps for the remaining time.

# METHODS

## new

    my $meteo = Weather::Meteo->new();
    my $ua = LWP::UserAgent->new();
    $ua->env_proxy(1);
    $meteo = Weather::Meteo->new(ua => $ua);

    my $weather = $meteo->weather({ latitude => 51.34, longitude => 1.42, date => '2022-12-25' });
    my @snowfall = @{$weather->{'hourly'}->{'snowfall'}};

    print 'Number of cms of snow: ', $snowfall[1], "\n";

Creates a new instance. Acceptable options include:

- `cache`

    A caching object.
    If not provided,
    an in-memory cache is created with a default expiration of one hour.

- `host`

    The API host endpoint.
    Defaults to [https://archive-api.open-meteo.com](https://archive-api.open-meteo.com).

- `min_interval`

    Minimum number of seconds to wait between API requests.
    Defaults to `0` (no delay).
    Use this option to enforce rate-limiting.

- `ua`

    An object to use for HTTP requests.
    If not provided, a default user agent is created.

## weather

    use Geo::Location::Point;

    my $ramsgate = Geo::Location::Point->new({ latitude => 51.34, longitude => 1.42 });
    # Print snowfall at 1AM on Christmas morning in Ramsgate
    $weather = $meteo->weather($ramsgate, '2022-12-25');
    @snowfall = @{$weather->{'hourly'}->{'snowfall'}};

    print 'Number of cms of snow: ', $snowfall[1], "\n";

    use DateTime;
    my $dt = DateTime->new(year => 2024, month => 2, day => 1);
    $weather = $meteo->weather({ location => $ramsgate, date => $dt });

The date argument can be an ISO-8601 formatted date,
or an object that understands the strftime method.

Takes an optional argument, tz, which defaults to 'Europe/London'.
For that to work set TIMEZONEDB\_KEY to be your API key from [https://timezonedb.com](https://timezonedb.com).

## ua

Accessor method to get and set UserAgent object used internally. You
can call _env\_proxy_ for example, to get the proxy information from
environment variables:

    $meteo->ua()->env_proxy(1);

You can also set your own User-Agent object:

    use LWP::UserAgent::Throttled;

    my $ua = LWP::UserAgent::Throttled->new();
    $ua->throttle('open-meteo.com' => 1);
    $meteo->ua($ua);

# AUTHOR

Nigel Horne, `<njh@bandsman.co.uk>`

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

Lots of thanks to the folks at [https://open-meteo.com](https://open-meteo.com).

# BUGS

This module is provided as-is without any warranty.

Please report any bugs or feature requests to `bug-weather-meteo at rt.cpan.org`,
or through the web interface at
[http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Weather-Meteo](http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Weather-Meteo).
I will be notified, and then you'll
automatically be notified of progress on your bug as I make changes.

# SEE ALSO

Open Meteo API: [https://open-meteo.com/en/docs#api\_form](https://open-meteo.com/en/docs#api_form)

# SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Weather::Meteo

You can also look for information at:

- MetaCPAN

    [https://metacpan.org/release/Weather-Meteo](https://metacpan.org/release/Weather-Meteo)

- RT: CPAN's request tracker

    [https://rt.cpan.org/NoAuth/Bugs.html?Dist=Weather-Meteo](https://rt.cpan.org/NoAuth/Bugs.html?Dist=Weather-Meteo)

- CPANTS

    [http://cpants.cpanauthors.org/dist/Weather-Meteo](http://cpants.cpanauthors.org/dist/Weather-Meteo)

- CPAN Testers' Matrix

    [http://matrix.cpantesters.org/?dist=Weather-Meteo](http://matrix.cpantesters.org/?dist=Weather-Meteo)

- CPAN Testers Dependencies

    [http://deps.cpantesters.org/?module=Weather-Meteo](http://deps.cpantesters.org/?module=Weather-Meteo)

# LICENSE AND COPYRIGHT

Copyright 2023-2025 Nigel Horne.

This program is released under the following licence: GPL2
