about boon

About BOON

Researchers

Projects

Partners

sensor platforms

Shoreline Observations

Offshore Mooring and Buoy Observations

High Frequency Radar

Vessel Based Observations

Resident Platforms

Products + Tools

All Real Time Observations

Sea Surface Currents

Research Products

Resource Managers

Recreation and Coastal Conditions

data

Summary of Data Sets

Data Access

Data Disclaimer & Terms of Use

rainfall

  • Real Time Data
  • 48 Hour Charts
  • Yearly Averages
  • Sensor Specs
  • Sensor Calibration
  • Data Access
Current Conditions Percentage of Annual Average
Last hour (inches) 0.0 0.0
Last 24 hours (inches) 0.2 0.6
Last 48 hours (inches) 0.2 0.7
Last 7 days (inches) 2.1 7.0
Last 30 days (inches) 2.9 9.4
Year to date (inches) 28.4 91.9
Rainfall Year, since July 1 (inches) 46.1 149.0
Rainfall Year, since Oct 1 (inches) 45.7 147.9
Last update: Mon Mar 27 15:10:00 2017 PDT Average yearly rainfall: 30.92"

All real time data >

Rainfall

Rain is the condensation of atmospheric water vapor into drops heavy enough to fall, often making it to the Earth's surface, and is the primary source of fresh water for most areas of the world. Because rainfall washes both organic matter and pollutants off the land and into the ocean, researchers are interested in tracking fresh water run off. Rainfall observations are used in conjunction with salinity measurements to observe river outfalls that create freshwater plumes in sea water. Meteorologists use rainfall and precipitation levels for tracking droughts, storm cycles and flood patterns. Ecologists study the effects of rain on primary productivity and animal life cycles.

Rainfall is measured with a tipping bucket rain gauge.

BML Rainfall

  AVERAGE TEMPERATURE RAIN RELATIVE HUMIDITY
Month Minimum Mean Maximum Inches 4 am Noon 4 pm
January 41.4 48.5 57.1 6.86 84 74 80
February 43.8 50.2 58.0 4.56 84 78 79
March 44.6 51.8 57.6 4.85 90 85 85
April 45.5 52.7 58.6 1.67 90 84 84
May 46.5 53.6 58.8 0.40 92 87 86
June 48.4 55.1 61.1 0.16 93 86 86
July 50.3 55.7 62.6 0.12 95 89 88
August 51.7 56.2 63.2 0.14 95 91 90
September 51.7 55.9 64.6 0.57 95 90 90
October 49.7 55.8 63.4 1.80 92 86 88
November 46.3 53.1 61.7 5.28 86 78 83
December 43.0 48.5 58.3 4.51 79 68 75
Whole Year 46.9 53.1 60.4 n/a 89.6 83 84.5
Total Average Yearly Rainfall 30.92

 

rainfall gaugeRainfall Gauge

Instrument Type: Hydrological Services TB4 Tipping Bucket Rain Gauge

Description: 200 mm diameter funnel directs precipitation into a bucket mechanism that tips when filled to a calibrated level; pulse-counting circuitry tallies number of tips

Location: 40 m from coastal bluff
Latitude 38° 19' 01.58" N
Longitude 123° 04' 18.61" W

Installed: September 2003

Specifications:
Resolution: 0.254 mm (0.01")
Range: 0 to 700 mm/hr (27.6 in/hr)
Accuracy: Better than 2% @ 500 mm/hr (19.7 in/hr)

Acquisition Settings:
15 second running total
Total tips logged hourly

Sensor Calibration and Quality Assurance Procedures

Rain Gauge

Equipment:

  • Hyrdological Services TB4 Tipping Bucket Rain Gauge S/N 02-192
  • Funneled Rain Bucket with Graduated Staff

Procedure:
After a rain shower, the amount of water collected in the funneled rain bucket is measured with the graduated staff.  This value is used to check the amount of rainfall recorded by the tipping bucket rain gauge.  After measurement, the bucket is emptied to prevent later comparisons from being affected by residual water in the bucket.