Data Tools: Daily Weather Records

The daily records summarized here are compiled from a subset of stations in the Global Historical Climatological Network. A station is defined as the complete daily weather records at a particular location, having a unique identifier in the GHCN-Daily dataset.

For a station to be considered for any parameter, it must have a minimum of 30 years of data with more than 182 days complete each year. This is effectively a "30-year record of service" requirement, but allows for inclusion of some stations which routinely shut down during certain seasons. Small station moves, such as a move from one property to an adjacent property, may occur within a station history. However, larger moves, such as a station moving from downtown to the city airport, generally result in the commissioning of a new station identifier. This tool treats each of these histories as a different station. In this way, it does not "thread" the separate histories into one record for a city.

This tool provides simplistic counts of records to provide insight into recent climate behavior, but is not a definitive way to identify trends in the number of records set over time. This is particularly true outside the United States, where the number of records may be strongly influenced by station density from country to country and from year to year. These data are raw and have not been assessed for the effects of changing station instrumentation and time of observation.

U.S. Records Summary

The summaries below list the number of records broken for several recent periods is summarized in this table and updated daily. Due to late-arriving data, the number of recent records is likely underrepresented in all categories, but the ratio of records (warm to cold, for example) should be a fairly strong estimate of a final outcome. There are many more precipitation stations than temperature stations, so the raw number of precipitation records will likely exceed the number of temperature records in most climatic situations.

U.S. Daily Records Summary

Period High Max High Min Low Max Low Min Precipitation Snowfall Snow Depth
Last 7 Days 157 282 262 123 314 74 0
Last 30 Days 4114 4632 789 370 1752 343 0
Last 365 Days 41248 45437 16222 13483 22422 4648 0
Month to Date 2193 2787 744 358 1394 283 0
Year to Date 11998 10592 8685 7442 6204 3076 0

U.S. Monthly Records Summary

Period High Max High Min Low Max Low Min Precipitation Snowfall Snow Depth
Last 7 Days 4 9 0 0 8 0 0
Last 30 Days 228 287 9 7 102 15 0
Last 365 Days 1733 2381 310 309 995 335 0
Month to Date 29 151 9 7 79 14 0
Year to Date 492 643 148 174 304 148 0

U.S. All Time Records Summary

Period High Max High Min Low Max Low Min Precipitation Snowfall Snow Depth