Narrative Summary - December 2002

The average temperature for December 2002 was much warmer than normal, averaging 37.2ºF, 5.5º above normal
(31.7ºF). The warmest December occurred in 1957 and averaged 38.5ºF, while the coldest, in 1985, averaged
21.0ºF. Except for the first 4 days of the month, every other day had average temperatures that were normal or
above normal. No daily temperature records were established during December 2002.

Precipitation for December 2002 was 2.36 inches, 213% of normal (1.11 inches). This was the second wettest
December on record. The wettest, in 1996, received 3.69 inches, while the driest, in 1976, received 0.11 inch.
Snowfall for December 2002 totaled 0.6 inch, compared to a normal of 5.8 inches. Total snow season
snowfall is only 0.6 inch, compared to a normal through December of 8.2 inches.

The barometric pressure (corrected to sea-level) on December 16 fell to a low of 28.91 inches of Mercury
(979.1 millibars). This was the third lowest pressure ever recorded at the HMS. The lowest ever was 28.86
inches on December 4, 1951.

The average wind speed for December 2002 was 5.7 miles per hour (mph), 0.3 mph below normal (6.0 mph).
The windiest December on record averaged 8.3 mph (1968), while the December with the lightest winds
(1985) averaged 3.3 mph. The peak gust for the month was 63 mph on December 27. The record wind gust for
December was 71 mph in 1955.

Calendar year 2002 was warmer than normal, averaging 54.4ºF, 0.8º above normal (53.6ºF). The warmest
years (1992 and 1998) averaged 58.2ºF, while the coldest year (1985) averaged 49.6ºF. The hottest
temperature for 2002 was 113ºF on July 13 (which tied the all-time high temperature), and the coldest
temperature was 7ºF on October 31. Precipitation for 2002 totaled 5.41 inches, 78% of normal (6.98 inches).
The wettest year (1995) recorded 12.31 inches, while the driest (1976) received 2.99 inches. A
comprehensive summary of calendar year 2002 will be published during the spring of 2003.

The monthly climatological data summaries, as well as other information, are available
on the Internet. Address: http://etd.pnl.gov:2080/HMS/. Hanford Site personnel can
access the HMS Intranet site at: http://hms.rl.gov/

For additional information contact:
Ken Burk373-3215
Dana Hoitink372-6414

Note: The information in this summary pertains specifically to
the Hanford Meteorology Station (HMS), which is located
approximately 25 miles northwest of Richland, Washington. No
attempt should be made to infer meteorological conditions at other
locations from these data.