Narrative Summary - September 2006

September 2006 was slightly warmer than normal, averaging 66.8ºF, 0.9º above normal (65.9ºF). The
hottest September (1990) averaged 72.4ºF, while the coolest (1985) averaged 58.8ºF. There were 8 days
in September with maximum temperatures >= 90ºF compared to a normal of 6. There were 69 days this
year with maximum temperatures >= 90ºF compared to a normal of 52 days. This was the 5th highest total
(the greatest number was 79 days in 1967). There were 3 days in September with maximum temperatures
>= 100ºF compared to a normal of <1, and a record of 3 on numerous occasions. The 100ºF maximum on
September 6 tied for the latest 100ºF day on record. This was only the second time on record that the
Hanford Meteorological Station has recorded 100ºF days in every month from May through September.
This also occurred on 1987. There were 24 days this year with maximum temperatures >= 100ºF compared
to a normal of 12. This was the 6th highest total (the greatest was 28 days in 1958). The following
temperatures records were established during September 2006:

                       New         Old
Date  Category        Record      Record        Year
   5  High Maximum     100         100          2003   Tied Record
  30  High Maximum      88          88          1993   Tied Record

Precipitation for September 2006 totaled 0.21 inch, 64% of normal (0.33 inch). The wettest September
(1947) received 1.34 inches, while the driest (1991 and 1999) received no precipitation. The period from
June 30, 2006 through September 13, 2006 (76 days) was the 3rd longest period on record without
measurable precipitation. The longest period was 81 days (beginning June 23, 1967 and ending on
September 11, 1967). Total precipitation for 2006 (through September) is 5.24 inches, 119% of normal
(4.40 inches).

The average wind speed for September 2006 was 6.7 miles per hour (mph), which was 0.6 mph below
normal (7.3 mph). The windiest September (1961) averaged 9.2 mph, while the September with the
lightest winds (1957) averaged 5.4 mph. The peak gust for September 2006 was 37 mph on September
13. The record wind gust for September was 65 mph in 1953.

The summer season of 2006 (June, July and August) was warmer than normal, averaging 75.1ºF,
1.4º above normal (73.7ºF). The hottest summer (1958) averaged 78.2ºF, while the coolest
summer (1980) averaged 70.2ºF. The summer’s highest maximum temperature was 113ºF on July
23, which tied the highest maximum temperature ever recorded at the Hanford Meteorology Station
(113ºF was also recorded on August 4, 1961 and July 13, 2002). Summer season precipitation
totaled 1.33 inches, 140% of normal (0.95 inch). All of the measurable precipitation was received
in June. The wettest summer (1950) received 2.99 inches, while the driest (1973) received only
0.03 inch.

The monthly climatological data summaries, as well as other information, are available on the Internet.
Address: http://hms.pnl.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.