MONTHLY WEATHER SUMMARY
By Laura Edwards
Western Regional Climate Center
September 2004

Read the full California Climate Watch newsletter here: Word Format or PDF format

Editor's Note: Bill Mork is on vacation this month.

A fairly uneventful September was punctuated by a record rainfall event in Sacramento on the 19th. The 1.93 inches in two hours on that date broke four records: all-time and September 1-hour rainfall (1.81"), September 2-hour rainfall (1.93"), September 30-minute rainfall (1.08"), and September 10-minute rainfall (0.38"). Most of these totals crushed previous records, with 10- to 10000-year return periods.

Overall the state average temperature was close to normal, coming in at 68.7 F, just 0.5 degrees above normal. Warmer maximum temperatures and cooler minimums statewide contributed to the near-normal conditions.

Most climate divisions had mixed results with stations recording positive and negative temperature anomalies in each division. Some remarkable stations include Richmond, Redwood City and San Francisco airport all averaging over 3 degrees above normal in the Central Coast. Porterville and Yosemite were both below normal for the month, with -3.4 and -2.8 degree departures respectively.

Precipitation statewide was around 22% of normal. The North Coast region reported the smallest precipitation departure with 31% of normal, and the Northeast Interior had the largest deficit with only 2% of normal precipitation reported.

Outside of the localized record precipitation event in Sacramento, most of the state was below normal for the month. Of the remaining stations reported in this Climate Watch, only Oakland Museum and Thermal airport had above normal precipitation.

Page last updated 10/11/04.