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WeatherCompare

Data Sources & Methodology

WeatherCompare does not run its own weather model. We bring together forecasts from independent weather services and publish long-term climate averages so you can see where the forecasts agree, and what the weather is usually like before you travel. This page explains where every number comes from.

Live forecasts

Each city page compares up to three independent forecast services side by side:

  • Open-Meteo (open-meteo.com): hourly forecasts up to 16 days ahead, built from national weather-service models. Data licensed under CC BY 4.0.
  • WeatherAPI.com (weatherapi.com): daily and hourly forecasts, plus official weather alerts where they are issued.
  • OpenWeatherMap (openweathermap.org): current conditions and a 5-day forecast in 3-hour steps; also the live temperature, rain, wind and cloud layers on our maps.

Every forecast block is labelled with the service it comes from. When the services agree, the forecast is usually more reliable; when they differ, the weather is harder to predict and it is worth checking again closer to the date.

Climate averages (month and “best time to visit” pages)

The monthly figures (average high and low, rainfall, humidity and cloud cover) are long-term averages of daily values for 2011–2020, grouped by calendar month. They describe what the weather is typically like, not a forecast for a particular year.

  • Most cities: NASA POWER (power.larc.nasa.gov), a global dataset produced by NASA’s Langley Research Center from satellite observations and the MERRA-2 reanalysis.
  • Coastal and island destinations: ERA5 reanalysis from the Copernicus Climate Change Service (ECMWF), retrieved through Open-Meteo’s historical weather API and adjusted to the height of the town or resort. ERA5 resolves small islands and coastlines far better, which matters because a coarse grid cell that is mostly sea understates daytime highs and overstates night-time lows.

The “best months” on each guide are chosen by scoring every month for comfortable daytime temperatures, low rainfall and sunshine. The same scores power the trip weather finder and the where-to-go pages.

How often data is refreshed

City forecast pages are rebuilt at least twice a day, and the “weather today” overview every three hours. Climate averages change only when we add cities or improve the underlying data.

Photos and maps

Destination photos come from Pexels and are credited to their photographers under each image. Maps use OpenStreetMap (© OpenStreetMap contributors), satellite imagery from Esri World Imagery, and weather layers from OpenWeatherMap.

Limitations

Forecasts from any service are estimates, and they become less certain the further ahead they look. Climate averages smooth out individual hot, cold or wet years. WeatherCompare is not a meteorological authority: for official warnings and any decision that affects safety, always follow your national weather service.

Attribution

Forecast data by Open-Meteo.com (CC BY 4.0), WeatherAPI.com and OpenWeatherMap. Climate data: NASA Langley Research Center (LaRC) POWER Project, funded through the NASA Earth Science/Applied Science Program; and Hersbach, H. et al. (2023): ERA5 hourly data, Copernicus Climate Change Service (C3S) Climate Data Store. Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.

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