Task: Get the current weather data for a city

n8n workflow JSON:
{"id":"88","name":"Get the current weather data for a city","nodes":[{"name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[250,300],"parameters":{},"typeVersion":1},{"name":"OpenWeatherMap","type":"n8n-nodes-base.openWeatherMap","position":[450,300],"parameters":{"cityName":"berlin,de"},"credentials":{"openWeatherMapApi":""},"typeVersion":1}],"active":false,"settings":{},"connections":{"OpenWeatherMap":{"main":[[]]},"On clicking 'execute'":{"main":[[{"node":"OpenWeatherMap","type":"main","index":0}]]}}}