MONTHLY WEATHER SUMMARY
By Jan Null
California State Climatologist, California Department of Water Resources
July 2005

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Following on the heels of a cool June, July 2005 was decidedly cool across most of the Golden State. Most of the month was dominated by strong high pressure aloft over the Desert Southwest expanding into California resulting in numerous record hot days over the state's interior. At the same time persistent surface high pressure over the Pacific kept coastal sections mild with a shallow but pervasive marine layer. The month was also relatively dry with the only significant precipitation due to afternoon thunderstorms in the High Sierra.

The Sacramento Basin had the largest positive average monthly temperature anomaly (+4.5 deg F) followed by the San Joaquin (+3.9), Southeast Deserts (+3.5) and the Northeast Interior (3.2). This was characterized by Sacramento which had their warmest average on record at 81.8 degrees; breaking the old mark of 81.6 degrees set in 2003. Likewise Sacramento's average minimum was a new record at 65.2 degrees but their month's average high was "only" the 4th highest at 98.4. Fresno had their 3rd hottest July on record while Bakersfield checked in with their 4th warmest.

Overall the coastal section's average monthly temperatures were near normal, ranging from a +0.5 degree anomaly on the Central Coast to +0.9 and +1.0 on the south and North Coasts respectively. However the individual average July 2005 temperatures for Los Angeles, San Diego and San Francisco were all slightly below normal.

Daily maximum temperature and also high minimum records were plentiful between the 10th and 31st with only five days when there was not at least one new record. These were mostly confined to the interior portions of California. Of particular note was the 94 degree reading on July 18 at Big Bear Lake (elev. 6790') which tied their all-time maximum record.

Also on July 18 the mercury rose to 129 in Death Valley, not a record for the date, but toasty none the less. This was in the middle of 11 consecutive days (July 12-22) when it was at least 120 in Death Valley, and on five of those days the minimum did not fall below 100 degrees! Their normal July maxima/minima are 115/86.

The hottest day of the month was July 17 when numerous desert locations set records, many of at least 120 degrees. There were new daily records for the day of 121 at Blythe and Imperial, 120 at Borrego, Palm Springs, and Thermal, plus 119 at Indio.


Page last updated 8/10/05.