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Weather Underground Launches New Weather Extreme Records Page

By: Christopher C. Burt, 9:49 PM GMT on February 25, 2012

Weather Underground Launches New Weather Extreme Records Page

A few days ago Weather Underground launched a fantastic new database that provides an unparalleled collection of historical extreme weather records for the United States and the World. This one-stop site is unique on the Internet and will allow users to search historical weather extremes in a variety of ways. The data may be found on the Wunderground front page under the ‘Severe Weather’ tab as ‘Record Extremes’. It features the following data collections:

Under the ‘Data Source’ link you will find three options labeled ‘NCDC Records (USA Only)’, Wunderground U.S. Records’ and ‘Wunderground Int’l Records’.

The 'Wunderground U.S. Records' provide historical extreme weather records for 304 sites in the U.S.A. that have long PORs (periods of record) and represent cities and locations wherein 90% of the country’s population resides within a radius of 50 miles. The data includes the following:

List of Wunderground U.S. Record parameters:


All-time hottest temperature on record.

All-time coldest temperature on record.

Warmest single month on record.

Coldest Single month on record.

Warmest summer (June-August) on record (not all sites have this information).

Coldest winter (December-February) on record (not all sites have this information).


All-time maximum 24-hour precipitation.

Wettest single month on record.

Wettest calendar year on record.

Driest calendar year on record.


All-time maximum 24-hour snowfall on record.

Greatest single snowstorm on record (amount inches).

Snowiest single month on record.

Snowiest winter season on record (July 1-June 30).

Greatest depth of snow on record.

NOTE: The "NCDC Records (USA only)" include all records from the NCDC database regardless of a site's POR or significance. This parameter is especially good for searching records for less significant sites with newer POR's and more recent events.

List of Wunderground Int’l records parameters

Hottest temperature on record ever measured for every country in the world.

Coldest temperature on record ever measured for every country in the world.

In the future we hope to add national records for maximum observed 24-hour precipitation to the above list, as well as other international weather extremes.

Special Features and Useful Tips

The icons of all the above data are located on a Wunderground map interface and are interactive. If you click on an icon more detailed information concerning the record will pop-up including dates of occurrence and special footnotes (in some cases) as well as more precise figures (for instance if precipitation amounts to hundredths of an inch rather than the tenths of inch displayed in the map icons).

The ‘Date Range’ function will also allow you to search the records using either limited date preferences (maybe you just want to know what new records were set last month or last year) or you can click on the ‘Show All Current Standing Records’ to view the entire period of record which, in most cases, go back to 1890 or earlier.

Please note that when choosing one of the ‘Weather Variables’ and ‘Record Types’ listed to the right of the ‘Date Range’ field you must be careful to choose just ONE ‘Weather Variable’ along with just ONE ‘Record Type’. Otherwise a great mishmash of data will appear on your Wundermap. If a particular ‘Weather Variable’ or ‘Record Type’ is not available the field will be in a shade of grey instead of black.

Please note that this is NOT a final product yet. There are still plenty of glitches and refinements to work out and work on!. Furthermore, lots of additional weather extremes will soon be added including U.S. state-by-state records for all variables mentioned (record temperatures, record precipitation, and record snowfall).

Please be patient and let us know your suggestions for improvement of the site and any problems you may come across.

A Little Background on the Database Development

The Wunderground U.S. and Int’l Records portions of the database was collected by me over the course of my research for my book here ‘Extreme Weather: A Guide and Record Book’ most recent edition of which was published in 2007 by W.W. Norton .

A cover of the 2007 version of my book ‘Extreme Weather: A Guide and Record Book’ that formed the basis of the data in Wunderground’s new ‘Record Extremes’ page. This does not include the NCDC records portion of the site.

In 2010 a tech-savvy (unlike myself!) friend of mine Tom Rauch digitized the tables of weather extreme records that appear in the appendices of my book and mapped and coded them into a user-friendly and interactive fashion that would make the data as up-to-date and internet-compatible as possible.

You may see this version here but keep in mind that the data herein is only updated to March 1, 2011 and also does not include some corrections I’ve since made to older data over the past year while Weather Underground worked on adopting the information for the new site. Be sure to click on "view map" at the end of each table to see the data herein displayed graphically and click on the icons for the all-important footnotes associated with most of the records displayed. I would like some feednack about how the information was displayed in this early version versus the new WU version. This early version is not really compatible for computer pads or mobile phones but looks nice on big desktop screens.

KUDOS: To Angela Fritz and Andrew Fink at Weather Underground for putting the project together and making a very complex thing work so well! Also thanks to Dr. Jeff Masters and Dr. Perry Samson (the founders of Weather Underground) for championing the project. The majority of the international temperature extremes were researched and compiled by Maximilliano Herrera, probably the world’s foremost temperature detective.

And special thanks to my friend Tom Rauch who talked me into allowing him to digitize the data and produce a product that ultimately led to my job at Weather Underground.

Christopher C. Burt
Weather Historian

P.S. I will be away on a business trip next week, so my next blog will not be posted until sometime in early March.

Extreme Weather

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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