Everything you need to know about how we track forecast accuracy across 2,200+ locations worldwide.
We help you find the most accurate weather forecaster for your location. Powered by ForecastWatch, we've compared billions of forecasts from major consumer and government weather services against actual observations for over 2,200 locations worldwide since 2004.
We compare each provider's 1-to-3-day forecasts against actual observations across four metrics: high temperature, low temperature, icon precipitation, and text precipitation. Each metric counts equally. Providers whose overall accuracy is within a small margin of the top performer for your area earn the "Superior Forecaster" label.
We find the nearest location where we have accuracy data. If it's within 50 km of your city, we show the results directly. If it's farther away, we note which location the data comes from. Weather patterns are generally similar within this range, so the results are still meaningful.
The 5-day forecast displayed on each city page comes from Open-Meteo, an open-source weather API. It's provided for convenience — the accuracy comparisons are what ForecastAdvisor is really about.
Accuracy is based on a rolling 12-month window, updated monthly. This gives a large enough sample for meaningful comparison while reflecting each provider's current performance.
We collect forecasts daily from major weather providers' websites and APIs for over 2,200 locations worldwide. Collection order is randomized to prevent any provider from having a systematic timing advantage.
Observations come from quality-controlled weather station data, verified with over 50 automated validity checks. We cross-reference temperatures, precipitation, and other measurements against historical ranges and neighboring stations.
Low temperatures are forecasted for roughly 12 hours further into the future than highs, making them inherently harder to predict. Overnight lows also depend heavily on cloud cover and wind patterns that are difficult to model precisely.
Changeability measures how much the weather varies from one day to the next at a given location. We track day-to-day temperature swings and precipitation transitions, then rank locations from most to least changeable. You can explore this data on any city page or on the Changeability page.
ForecastWatch provides detailed forecast accuracy analytics to weather industry professionals and providers. ForecastAdvisor is the free, public-facing side — giving consumers a simple answer: who gets your weather right?