My 15 Day Forecast (2024)

FAQs

How accurate are 15 day forecasts? ›

The Short Answer: A seven-day forecast can accurately predict the weather about 80 percent of the time and a five-day forecast can accurately predict the weather approximately 90 percent of the time. However, a 10-day—or longer—forecast is only right about half the time.

Better accuracy means better decisions

Powered by proprietary GRAF technology (Global High-Resolution Atmospheric Forecasting), The Weather Company is The World's Most Accurate Forecaster¹ and a trusted weather partner for people and businesses everywhere.

This comprehensive test analyzed over 25 million weather forecasts in more than 1,000 locations globally, and AccuWeather was the clear winner in high- and low-temperature forecasts, proving to have the lowest average absolute error and the greatest percentage of forecast accuracy within 3 degrees F.

10-day forecasts have an accuracy rate of about 50%. That means about half of the time you look at the 10-day forecast, it will not be correct. This makes it difficult to plan outdoor activities and travel in advance, which can be frustrating, but there is still value in having an idea of what the weather might be.

Let's look at an example of what the probability does mean. If a forecast for a given county says that there is a 40% chance of rain this afternoon, then there is a 40% chance of rain at any point in the county from noon to 6 p.m. local time.

Even now five-day weather forecasts are about 90% accurate, but 10-day forecasts are more like 50%. Anything beyond that becomes speculative.

July 29, 2021. IBM and its subsidiary The Weather Company continue to be the overall most accurate weather forecast providers worldwide, according to a new study. The Weather Company includes weather.com and other digital properties of The Weather Channel.

In a composite measure of accuracy, the Weather Channel and Weather Underground came top, AccuWeather fifth, MeteoGroup (the BBC's new provider) sixth and the BBC ninth (based on Met Office forecasts).

IBM and its subsidiary The Weather Company have been named the 'overall most accurate provider globally' by ForecastWatch, a technology-driven weather forecast monitoring and assessment company.

Closer look at percentages

Let's use 60% as the rain chance in the forecast. That means 60% of the entire area (Central Florida) could see measurable rain at some point in the day, while the other 40% won't.

How accurate is a forecast a week away? ›

During this period: Accuracy for temperature forecasts is usually within 2-3°F. Precipitation forecasts are correct about 80-85% of the time. Timing of weather events is generally spot-on.

Forecast accuracy is the measure of how accurately a given forecast matches actual sales. Forecast bias describes how much the forecast is consistently over or under the actual sales. Common metrics used to evaluate forecast accuracy include Mean Absolute Percentage Error (MAPE) and Mean Absolute Deviation (MAD).

An assessment from the Post determined that the 45-day forecasts were not even able to predict trends accurately, and that, although the forecasts did not decrease in accuracy with time, the forecasts were so far off even in the short range as to be useless.

Most experts would agree that a good accuracy forecast percentage is any percentage above 70%. It's important to note that this greatly depends on industry and demand. For example, in retail, where there is a lot of competition and the market is constantly changing, the margin error can be made lower.

Short-term forecasts are more accurate than long-term forecasts. A longer forecasting horizon significantly increases the chance of unanticipated changes impacting future demand. A simple example is weather-dependent demand.