Learn what is weather history, why do you need it for weather forecasting and where to get it in Windy.app.
The history of the weather is statistical data on the state of the atmosphere and the ocean, collected on the basis of regular meteorological observations made from hour to hour, day to day, month to month, year to year — continuously.
The purpose of data collection is the same as any other statistical information: to better understand the current weather situation and make better forecasts.
For example, by comparing the wind speed in a particular area over the past few years, we can identify patterns like "the wind blows mainly in the same direction and with the same speed". The conclusion: it will continue to blow in the same way. If the wind is unstable, it is more difficult to predict the weather.
Forecast and reality often don't match. Sometimes we need to look at the real weather at some particular point. And what could be wrong with that?
The weather is monitored all over the world. There are a lot of sources: weather stations, satellites, weather balloons, ships, aircraft and other, datasets of enormous size. However, there is a problem: these records are not evenly distributed around the globe.
Knowing weather history can help you with these questions. Thanks to it, you can compare the actual weather on any date to the normal weather in past years. So you need to know the weather history for the same thing — for better weather forecasting.
Important: remember that in some regions the weather changes frequently and significantly. In Iceland, for example, you can get only a primal understanding of the conditions of wind and precipitation. But in other places (in Japan in winter, in Southern Europe in summer, etc.) the weather is pretty constant from year to year. In these places, historical data can sometimes be used as a rude forecast.
And in general, the weather is cyclic. In the same regions of the earth at the same time periods, it is approximately the same. Yes, in the southern regions may snow, but usually, it is very hot there, and in the north — cold. Somewhere, like in Tarifa, the wind is always blowing, so it is one of the best places in the world for kitesurfing. Somewhere, like in California, the best waves. And so on.
In Windy.app weather history is the weather that occurred on a spot in the past. This data is taken from the forecast for the spot and is available since 2012.
Before 2021, the history used to be old GFS27 global model forecasts. From year 2021, we give you a completely different past weather data — reanalysis of the ECMWF — #1 global weather forecast model.
The difference with the previous forecast is that ECMWF works "backward" in time and processes all available weather observations made in past. The result is comprehensive retrospective weather data for any point on Earth for every 3 hours.
The feature is called Weather Archive.
In the Archive you can find
Wind and temperature are available as monthly (weather history by month) and daily means (weather history by date), precipitation is available as monthly and daily sums.
These statistics are based on historical data observations and were created for windsurfing, kitesurfing, sailing, and other extreme sports activities. All statistics update every year and can help to find the best place for any wind and water sport.
In Windy.app you can get Weather Archive in two places: for a particular spot (and other locations) and for the world on the Wind and Precipitation Map. You can read about how to use the weather archive on the website in our guide.
Let's take iOS as an example:
In the app
1. Choose and open any spot, scroll down the screen, find and tap on the Archive icon.
2. On the first Archive screen you see the wind direction and wind speed history for each month for the last years, as well as the wind, rose showing the same, but in a different way. Learn how to read wind rose in Windy.app.
3. Slide from the left to the right of the screen to see the colors and numbers of wind speed.
4. At the bottom of the first screen tap Detailed archive to see more data.
5. On the archive second screen you see the same historical weather records, but for each day of the month. Plus: wind gusts, atmospheric pressure at sea level, clouds base, and precipitation. Choose any day to see how the wind rose will change.
On the website
You can check windy historical data and temperature history (but, in this time, no historical precipitation data) for any spot on the Windy.app website. It contains the same detailed information about the average local wind speed and air temperature. The same wind rose on the map shows a dominant wind direction and includes average data for every year.
Here you also get free historical weather data by city. Let's take some examples:
1. Open the Wind and Precipitation Map from the same spot or the Home screen.
2. Tap on the Wind Gust Icon and choose Wind archive.
3. Here you get an average wind speed forecast for each month for recent years on a big wind map — so in a different way, then on the spot archive.
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Text: Evgeniy Petrov and Ivan Kuznetsov
Cover photo: haley-truong / unsplash