How Accurate Is a 7-Day Forecast?
A seven-day forecast is genuinely useful — but not equally at every range. Knowing where the reliable part ends helps you plan without being surprised.
Why accuracy drops across the week
Weather is a chaotic system: tiny uncertainties in today's measurements grow rapidly over time. In practice a next-day forecast is right around 90% of the time for temperature and general conditions, a three-day forecast is still strong, and by day six or seven you are looking at a trend, not a promise. That is why the far end of any weekly outlook — ours included — should be read as "warming up" or "a wet spell coming", rather than an exact figure.
How to use a weekly outlook
- Trust the next 1–2 days for firm plans like what to wear or whether to carry an umbrella.
- Treat days 3–5 as a good steer for loose plans, and re-check closer to the date.
- Read days 6–7 as direction only — the shape of the week, not the detail.
Re-checking the day before always beats relying on a week-old outlook, because each new run folds in fresh observations.
What a "60% chance of rain" actually means
A precipitation probability is not how much rain will fall or how long it will last — it is the chance that a measurable amount falls at a given point inside the forecast area. A 60% day can still be dry where you are standing, and a 30% day can soak you for ten minutes. The figure shown against each day in the tool is the maximum probability across that day, so read it as "how likely is rain at some point", not "how wet will the whole day be".
Why two forecasts disagree
Different apps run different models, or the same model from a different run, so a five-day outlook can differ by several degrees between sources without either being wrong. Ours reflects the Open-Meteo blend at the moment you loaded the page; reloading tomorrow pulls a newer run that has seen another day of observations.
Check the 7-day outlook and re-check it as your plans firm up.
Open the Weather Forecast tool