What Was the Weather on a Certain Date?

What was the weather on a certain date? Whether for scientific, business or recreational purposes, people are increasingly seeking historical weather data. Here we explain what kinds of historical weather data exist, where to get them from, and how Meteomatics can help you on your journey.

What Kinds of Past Weather Data Are There?

The way you find past weather data depends on the type of data you are interested in. There are a few major types, which are all created in different ways by different organisations, and usually hosted by those organisations.

The first kind of historical weather data we often think about is that measured at ground based observatories. These types of observations have been available for much longer than other types of weather data — sometimes for centuries! Whilst they tend to be accurate — since they are direct measurements — they only provide data for specific times, places and variables.

In addition to direct observations, the discovery of the electromagnetic spectrum has allowed us to invent new methods of probing the atmosphere indirectly, and these are employed by radar and satellites. These provide much greater spatial coverage, but are considered slightly less trustworthy because the measurements are made indirectly and must be mathematically interpreted.

When observations aren’t available, we have to fall back on model data. There are two reasons to do this, which lead to the two different types of model data available for historical weather. First, when considering the future, we make weather forecasts. These are by definition models, as no observations from the future exist at the time of production. However, once some time has elapsed, the period predicted by the forecast will slip into the past, and the predictions once made for tomorrow instead become "historical forecasts".

A logical follow-up question is: now that the time period covered by the model is in the past, observations are available — can we use these to update the model and make it more accurate? This is the principle of a "reanalysis". Using a consistent model applied over a long period of time, and constraining it by providing "correct answers" at the locations of real observations, we can create our best guess of the full state of the atmosphere, including many more variables than are observed by your typical ground-based observatory.

How to Find Past Weather Data

There are a few places to look for historical weather data, depending on which of the above types you want. For historical observations and forecasts, the first place to look is the national meteorological service of the country you’re interested in. Of course, often, you’ll have questions about regions which span several national boundaries. In this case, NOAA maintains large repositories of SYNOP and METAR data.

For renalayses, your search should start with one of the large reanalysis production centres like ECMWF.

How to Download Historical Weather Data

Downloading historical weather data can also be done on the websites of NOAA and ECMWF. However, doing so often requires some programming knowledge, as the data must often be accessed via scripts, and in the case of reanalyses and historical forecasts, is often too large to be downloaded all in one piece, meaning it must instead be split up either in time or in space and recombined by the user.

Meteomatics makes this easy for our users — all of this work has already been done in our backend, meaning you can choose from any of the parameters in our parameter list, any of the various data sources (including station, radar and satellite data; historical forecasts; and reanalyses from many different meteorological centres) and any place, and we can provide you with downscaled data at 90m spatial resolution all the way back to 1940.

Historical Weather Data by ZIP Code

By accessing historical weather data by ZIP code, you can gain insights into long-term weather trends and patterns that can inform decisions related to things like construction, outdoor events, or agriculture.

At Meteomatics, we offer a wide range of historical weather data solutions by ZIP code, designed to meet your specific needs and help you make informed decisions. Our URL Creator featuring a text search bar means that you can use our API to search via ZIP or postal code for the most accurate weather information.

How to search historical weather data by ZIP code

Historical Hourly Weather Data

With historical hourly weather data, you can access information on temperature, precipitation, wind speed and direction, humidity and more, at hourly intervals for specific locations. This data is particularly useful for industries such as energy, transportation, and logistics, where detailed weather information is crucial for decision-making.

As well as downscaling the spatial resolution of the data, we interpolate in time for you in the backend, so even if you’re accessing data from a station with a resolution of three hours, we can serve that data to you at resolutions of as little as five minutes!

How to search historical hourly weather data

Free Historical Weather Data

With our Free Basic Weather API subscription plan, you can only look 24 hours into the past. However, if you’re interested in leveraging the power of historical data, get in touch with us and request a trial — a subset of our historical data can be included in a two-week trial and you can see for yourself how useful it is!