When planning a field trip, what is the first question to ask? “What’s the weather going to be like this week?”, of course. Weather plays a big role in our day-to-day life, so of course, we want to know what it’ll be like as soon as possible. But you surely noticed when playing Weather Challenge, predicting the weather is not an easy task.

Weather forecast accuracy

We all know that the most reliable forecast is the one to show weather in next 24h. Logically, the shorter time of forecast, the more accurate prediction, because there are unforeseen circumstances that can influence the end result. Of course, as our measuring equipment is getting more accurate and as we’re learning more about the weather itself, our predictions are getting better. Today our forecast for 5 days is as accurate as a forecast for 3 days was back in ‘95.

Weather forecast for 7 days

We’re making progress, but is it enough to accurately predict what weather for a week to come? The answer is: not yet. General accuracy for the 7-day forecast is around 40%. That’s not too much, especially given that 1-day forecast has almost 90% accuracy, while 3-days forecast above 70%. Of course predictions of different weather components have different reliabilities. Predicting maximum temperature is generally easier, than predicting rainfalls or sunshine. Also, the real temperature can be very different than the one we’re perceiving. Wind, humidity and other factors can influence our senses, making the weather more or less pleasant.
Still, this doesn’t mean that 7-day forecasts are completely useless. Although they won’t provide us with details, they can serve as a general indicator of what we can expect. And remember that our forecasting methods are getting better – in the 1980s the 7-day forecast was as good as today’s 10-forecast. And in upcoming years their reliability will increase even further.