In California, El Niño often results in warmer ocean temperatures which can have a number of effects, including impacts to kelp, the amount of nutrients in the surface ocean, and the movement of species. Use this tool to explore changing temperatures and compare to previous years.
Percent Difference Metric - shows how different today's measurements are from what has been observed at the station in the past. For the length of record at a given site a daily mean is calculated (not including this year). If we have 5 years of data prior to this year, then for the day March 23, 5 values are averaged together to create an average for this date. This combined 'previous years' average is compared with the average temperature on March 23 of the current year to yield a percent difference. The percent difference calculation is based on degrees Fahrenheit. This calculation is not a climatology, anomaly or index, for more information on those products and methods see the links in the "Learn More" section.
Percentage of Days Metric - shows how often we are observing a day with a higher than average temperatures at a given station. The average temperature on a given day is calculated from sensor measurements in years prior as described in detail in the percent difference metric explanation. This year's daily measured temperature at the site is then compared to the 'combined average from pervious years'. For each day, if this years temperature value is higher the the combined previous years average it is tallied. The sum of the tallies is then divided by the number of days in a year to yield the percentage of the year with higher then averag temperature metric.
Chart Description
The blue line is the daily average water temperature for the station over the past year. The gray line is an average of the daily values for that day over the length of record the station has been collecting water temperature measurements. Raw data has been quality controlled, plots may show gaps in the time-series where suspect data has been removed. Full data records are available for download through the data access link below.
