I live in the San Francisco Bay Area and have always had a fascination with weather, its extremes, and stats. I'm also in CoCoRaHS: Belmont 0.7 WSW.
By: BelmontJeff, 4:08 PM GMT on September 01, 2013
Temperature: August saw a very cool start, with the first 9 days not reaching 70° for Maximums. The 73.1° reading on the 10th ended a 14-day streak of Maxs. ≤70°, dating back to July 27th. The Avg. Max. Temp. for the first 9 days was 68.1°; from the 10th to the 31st the Average Max. was 78.1°. The month's extreme Max. Temp. of 94.4° (18th) was the first ≥90° Temp. since June 29th, a string of 49 days, and the only August value ≥90°. The month's Avg. Max. Temp. of 75.2° was 0.1° below June's, the current warmest month this Calendar Year.
Daily Min. Temps. varied less than 10° in the month. Four days remained ≥60° and 12 were ≤55°. August's Average Min. Temp. of 56.1° was the warmest monthly average for this current Calendar Year, 1.8° warmer than June, now the second warmest.
No Cooling Degree Days occurred 1st-12th (and dating back to July 27th); no Heating Degree Days occurred 24th-31st. The greatest diurnal range was 38.3° (18th), the least was 11.8° (23rd).
Precipitation: Surprise showers fell the morning of Aug. 7th, bringing the first measureable precip. since June 25th, a 42-day stretch. With a 0.03" total (from 2 days of measurable rain), August ended up below the 30-Year Normal of 0.09" for the month. The current Calendar-Year Total Rainfall for January-August 2013 continues well below normal: Vantage Pro2 Gauge = 2.36", Lake Region Gauge = 2.74" (Normal is now 17.15").
Wind: All 31 days recorded peak gusts of ≥10 MPH, with 24 of these being ≥15 MPH and 8 ≥20 MPH.
Fog: 9 of the first 15 days had Fog (2 with Visibility ≤1/4 Mile) but only 5 more occurred the rest of the month (also 2 with Visibility ≤1/4 Mile).
Updated: 6:41 PM GMT on September 04, 2013