WeatherChirp is a free web app showing typical temperature, rain, and sunshine for every month for 30,000+ cities worldwide. It's built from ERA5/Copernicus 30-year climate normals (1991-2020), so you can plan trips around typical weather rather than a short-term forecast. Features include best weather by month rankings, a world temperature map, browse by country, and city comparisons.

I kept trying to plan trips and could never find a simple answer to "what is the weather usually like there in March?" Forecasts only cover two weeks, so I built WeatherChirp on 30 years of climate data to answer that question for any city.