Caveats regarding OpenWeatherMap API

Temperature unit inconsistencies

OpenWeatherMap returns temperatures either in Celsius or Kelvin. There is no indication of which unit is currently in effect and the API does not document this inconsistency. Examples are:

// http://api.openweathermap.org/data/2.5/weather?q=London,uk
// Archive: http://web.archive.org/web/20150315104056/http://api.openweathermap.org/data/2.5/weather?q=London,uk
{
    "main": {
        "temp": 285.55,    // Kelvin
        "pressure": 1020,
        "humidity": 82,
        "temp_min": 283.15,
        "temp_max": 287.15
    }
    ...
}

// http://api.openweathermap.org/data/2.5/box/city?bbox=12,32,15,37
// Archive: http://web.archive.org/web/20150706053457/http://api.openweathermap.org/data/2.5/box/city?bbox=12,32,15,37
{
    ...
    "list": [{
        ...
        "main": {
            "temp": 23.92,      // Celsius here
            "temp_min": 23.915,
            "temp_max": 23.915,
            "pressure": 1031.47,
            "sea_level": 1032.82,
            "grnd_level": 1031.47,
            "humidity": 95
        }
        ...
    }]
}

Incorrect Geo-info in Europe and Asia

City data was taken from OpenWeatherMap API. We received complaints from Russian customers saying that it provided them with wrong city information. Similar problems happened in China, where incorrect city names are occasionally reported. Below are some relevant screenshots.