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Boulder Temperature Records

This NOAA Website has complete Boulder temperature and precipitation listings. There are temperature records from 1898; precipitation is included beginning Aug 1, 1948. The latest month is usually added sometime during the next month. On a related page, there are also graphs of normal and record highs and lows. Each graph has normal low or high, plus both the highest and lowest record of that type. Click on the links below to see copies of these graphs.

The official Boulder weather station has moved several times during the time of the daily data, as described on another NOAA Web page.

These data sets can be used for hours of statistical games. Two examples are our reviews of hot summers and cold winters. Because of the changes of weather-station location, Boulder is a poor candidate for temperature trend analysis. However, we've looked at trends anyway.

Another topic of interest is the earliest or latest date of occurrence of a particular temperature. This is of particular concern in the winter, when low temperatures can lead to frozen pipes. Finding these dates required analyzing the complete daily temperature record file. In each row the indicated date is the earliest or latest that a temperature equal to or less than the specified temperature for that row was observed.

Temperature Earliest Date (Year Occurred) Latest Date (Year Occurred)
-20 Dec 21 1990 Feb 8 1936
-15 Dec 6 1972 Feb 10 1933
-10 Dec 5 1972 Mar 12 1932
-5 Nov 25 1993 Mar 27 1931
0 Nov 2 1951 Apr 2 1975
5 Oct 31 1991 Apr 12 1997
10 Sept 26 1994 Apr 11 1940
15 Sep 30 1985 Apr 20 1966
20 Sep 29 1985 Apr 21 1982

However, if you'd like a guide to when to service the swamp cooler, here are the dates for the high end of the temperature scale. Here, the dates in each row are the earliest and latest that a temperature above the indicated value was recorded.

Temperature Earliest Date (Year Occurred) Latest Date (Year Occurred)
85 Apr 7 1988 Oct 23 2003
90 May 15 1978 Sep 30 1980
95 May 28 2000 Sep 13 1990
100 Jun 14 2006 Sept 2 1983



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