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, 7:39 PM GMT on November 02, 2013
OCTOBER was a pleasant month, with 18 Clear days, 0 Cloudy days, and mild weather, for the most part, until near month's end. Only 2 days of AM Fog were observed 1st-18th (1 of these Heavy, Visibility <1/16 Mile); 10 more days w/ Fog occurred 19th-29th (3 being Heavy), except for the 25th.
Avg Max: 75.1°
Avg Min: 52.1°
Due to the many clear periods, the disparity between the Average Max. and Min. Temps. of 23.0° was, so far, greater than any other month this year, just beating out April's 22.8° difference.
The Average Max. Temp. over the first 20 days was 78.0° but only 69.6° from 21st-31st. Max. Temps. peaked on the 5th & 6th at 87.1° (2 of the 11 days in the month to reach ≥80°).
Min. Temps. differed only 14.6° from warmest to coldest readings. The Avg. Min. Temp. 1st-19th was 54.0°; from 20th-31st it was 49.1°. Following September, which had the year's warmest Avg. Min. Temp. at 57.5°, October's 52.1° was 5.4° cooler, though the Avg. Max. Temp. was only 4.1° lower (79.2° vs. 75.1°).
The sharpest day-to-day change was from the 26th-27th when the Max. Temp. went from 80.7° to 57.3°, a 23.4° drop. That Max. reading on the 27th was the Coolest since the 56.2° on Apr. 15, 2013.
PRECIPITATION: The average monthly rainfall for October is 1.34". We were far from that value this year as only 0.03" was recorded, just 2% of Normal.
The current Calendar-Year Total Rainfall also continues well below normal, now at 3.06" (Normal for the period January-October is 18.64"). At this point in the Calendar Year, this is probably the driest ever recorded.
WIND: Only 16 of the 31 days recorded peak gusts of ≥10 MPH, with 6 of these being ≥15 MPH, and 2 ≥20 MPH. Very light winds 13th-26th.
Updated: 5:04 PM GMT on December 04, 2013