Air Temperature as an Abiotic Factor at Race Rocks

Air Temperature as an Abiotic Factor at Race Rocks

Extreme Temperature Values at Race Rocks Ecological Reserve Since 2006-04-21

The present air temperature, measured at 1.5 metres above the rock surface at Race Rocks
The above graph shows the temperature data for the past week at Race Rocks. Temperature is a major factor affecting the distribution of terrestrial and intertidal organisms at Race Rocks. In the winter, the air temperature rarely falls below 0 degrees Celsius because of the surrounding moderating effect of the ocean, which does not go below 7degrees C in winter, or above 13.5 degrees C in the summer. In the summer, only those organisms which can tolerate or regulate the heat can survive, as July and August are often warm and dry. (see yearly means, highs and lows in the graphs below.)
Today's Outside Temp the past weeks's temperature the past months temperature
The last 24 hrs. air temperature The past week’s air temperature The past month’s air temperature.
Temperature month summary
This display is of the past month’s summary provided by the UVic School Base Weather Station Network. Click on the graph to go to their site for an interpretation of the graph.
We have provided the data from our Davis weather station output to the UVic School Based Weather Station Network. The graphs above have been derived from their analysis.
This new graphical display from the www. site of all years shows common and deviant patterns of temperature. Each year is represented separately below.


Yearly temperature average
2012 Maximum, minimum and means are shown ( Includes data and graphs at this site. ) Gaps represent instrument failure.
Yearly temperature average
2011 Maximum, minimum and means are shown ( Includes data and graphs at this site. ) Gaps represent instrument failure. temperaturegraph2010
2010: Maximum, minimum and means are shown. (Includes data and graphs at this site.) Gaps represent instrument failure which resulted in replacement.
Yearly temperature average
2009: Maximum, minimum and means are shown. ( Includes data and graphs at this site.)
Yearly temperature average
2008: Maximum, minimum and means are shown. ( Includes data and graphs at this site.)
Yearly temperature average
2007: Maximum, minimum and means are shown. ( Includes data and graphs at this site.)
Yearly temperature average
From May 2006: Maximum, minimum and means are shown. ( Includes data and graphs at this site.)
high temp 2006 Low temp
Click here for the high temp outside for 2006 Click here for the low temp outside for 2006
2006 temp
Year temperature
Click here for a graph of November 2005- November 2006 Air Temperature at Race Rocks.The Davis Weather Station was started in November of 2005, so the records above are from that instrument.
Previous to January 2006, the Maximum, minimum and mean temperatures were determined manually every day at 1800 hrs. by the Light keeper in the early years and the Race Rocks Guardian after 1997.
Stephenson Screen
Max-Min Temp
In this photo, Rosie a student from Pearson College spending her Project week at Race Rocks records the maximum/minimum temperatures at 1800 hrs. This is the type of maximum/minimum thermometer used in the Stephenson screen for the manual determinations.. The daily weather duties were explained by the students in this video : Daily Duties For Assistants to the MPA Guardian


Indexed in this file are the daily atmospheric temperatures and precipitations as recorded by Mike Slater, Marine Protected Area Guardian, from April 1998 to December 2005.
 temperature archivesOctober 1984 to February 1997 daily weather records submitted to Environment Canada Meteorological Service by the light keepers at Race Rocks. Be sure to do a Customized Search for “Race Rocks Lightstation” to find this archive.
See also for correlational studies: The Race Rocks mean Monthly Sea Water Temperatures 1921-present,
Sea Temperature as an Abiotic Factor.
The following parameters are included on this page because they are based on calculations involving the temperature. It makes it obvious that one should not look at one weather factor alone in determining the reality of the weather.For an Advanced explanation of the Derived Variables such as wind chill, ET, heat Index, etc. See this link.
The WIND CHILL at RACE ROCKS: The software calculates wind chill based on the temperature and wind speed readings for the archive period (that is, the temperature at the end of the archive interval and the average wind speed during the interval). WeatherLink uses the Osczevski (1995) equation to calculate wind chill. This is the method adopted by the US National Weather Service in September of 2001.


2006 windchill
The present wind-chill at Race Rocks, measured at 1.5 metres above the rock surface. See the Wind Data page. Click on above for WIND CHILL for 2006




2006 heatindex
The present Heat Index, calculated from sensors 1.5 metres above the rock surface at Race Rocks The Heat Index for the past week at Race Rocks.Also see the HUMIDITY as an Abiotic Factor page: Click on above for the Heat Index for 2006


The Heat Index calculated for this current week at Race Rocks. The Heat Index, also known as the Temperature/humidity index (THI) uses the temperature and the relative humidity to determine how hot the air actually “feels.” When humidity is high (i.e. the air is saturated with water vapor) the apparent temperature will be higher than the air temperature because perspiration cannot readily evaporate into the surrounding air. Technically, Heat Index is calculable only when air temperature is above 68 °F (20 °C) because it is a measure of heat stress, which is not significant at lower temperatures. Davis Instruments smooths the curve relating air temperature to Heat Index between 68 ºF (20 ºC) and 57 ºF (13.9 ºC). Below 57 ºF (13.9 ºC), the Heat Index is equal to outside temperature. Conversely, 135 °F (52 °C) is the highest Heat index for which calculation factors are available. Note that at very low humidity values, the air temperature can be as high as 140 ºF. In terms of storage to the data logger and database, Heat Index is a special case. It is not stored in archive memory or in the database, rather it is calculated as necessary (for example, when plotting or displaying database information). When Heat Index data is needed, the software calculates an average for each archive interval based on the temperature and humidity readings for the archive period.
The THW INDEX at RACE ROCKS: The THW Index uses humidity, temperature and wind to calculate an apparent temperature that incorporates the cooling effects of wind on our perception of temperature


. .
The Temperature Humidity Wind Index as calculated from sensors 1.5 metres above the land surface at Race Rocks. THW: Temperature Humidity Wind Index:


The THSW Index uses humidity, temperature, the cooling effects of wind and the heating effects of direct solar radiation to calculate an apparent temperature
The DEW POINT at RACE ROCKS: The Dew Point: Dew points indicate the amount moisture in the air. The higher the dew points, the higher the moisture content of the air at a given temperature.Weather conditions at locations with high dew point temperatures (65 or greater) are likely to be uncomfortably humid
Dew point temperature is defined as the temperature to which the air would have to cool (at constant pressure and constant water vapor content) in order to reach saturation. A state of saturation exists when the air is holding the maximum amount of water vapor possible at the existing temperature and pressure. The present dew point at Race Rocks, measured at 1.5 metres above the rock surface. See the Humidity Data page. When the dew point temperature and air temperature are equal, the air is said to be saturated. Dew point temperature is NEVER GREATER than the air temperature. Therefore, if the air cools, moisture must be removed from the air and this is accomplished through condensation. This process results in the formation of tiny water droplets that can lead to the development of fog, frost, clouds, or even precipitation. Relative Humidity can be inferred from dew point values. When air temperature and dew point temperatures are very close, the air has a high relative humidity. The opposite is true when there is a large difference between air and dew point temperatures, which indicates air with lower relative humidity. Locations with high relative humidities indicate that the air is nearly saturated with moisture; clouds and precipitation are therefore quite possible. .
EVAPOTRANSPIRATION at RACE ROCKS: ET has been calculated based on the temperature/rainfall data as measured at 1.5 metres above the rock surface at Race Rocks.This is the amount of moisture evaporated off the surface.  Using this data with rainfall, one can determine moisture deficits/surpluses. Also See the Rainfall/ Precipitation Page.


For Current Temperatures on a Global Scale, go the the website”Space Weather Now” and click on terrestrial.

The ABIOTIC EFFECTS of TEMPERATURE on Organisms at Race Rocks

The effects of air temperature on the distribution of organisms at Race Rocks.

In this video we discuss the effects on diatom growth from the increasing temperature which results from the increasing levels of solar energy in the early spring of 2006 in the upper intertidal zone on Great Race Rocks.

rafting california sea lions california sea lions california sea lions


1. Marine Mammal Adaptation: In the pictures above from the California Sea lion page, the behaviour of rafting of sea lions is evident just off the jetty at Race Rocks. Since the pectoral flippers are filled with blood vessels and are very thin, thus having a high surface area to volume ratio, exposure to the atmosphere can assist in thermoregulation.
gull cormorant drying temperature adaptation
A nesting Glaucous-winged Gull as seen by camera 1 on a hot day in July. Double-Crested Cormorants are frequently seen drying their wings, temperature regulation is possible as well. When a bird tucks its beak under its feathers, it conserves body heat by breathing warm air from the insulation of the feathers. PB photo Dec.2008

2. Bird Temperature Regulation Behaviour : Sea gulls nest at Race Rocks during the hottest part of summer. While incubating the eggs, they can often be seen panting as in this photo. Cormorants will often extend their wings to get more surface area for heat exchange or for drying plumage.

Halosaccion glandiforme Halosaccion glandiforme
The water -filled cavities of the red algae Halosaccion A field of Halosaccion glandiforme
3.Macroalgal Adaptation to temperature: TheseHalosaccion are macroalgae living in the intertidal zone and they also have effective thermoregulation mechanisms. The tubular sacs are filled with water and there are tiny holes surrounded by regulating cells in the end of the sac. At low tide these sacs slowly leak water. Evaporation lowers the temperature of the algae’s surface thus providing an efficient cooling mechanism.
Romanzoffia tracyi Romanzoffia tracyi or mist maidens as they appear between March and May. Throughout the winter their fleshy leathery leaves remain green.
4. Terrestrial Plant Adaptations: There are very few areas in Canada, and certainly, only on the Pacific Coast where the temperatures remain warm enough in the winter to permit plants such as this to retain their green leaves. Typically, these plants only grow within a few meters of the seashore, usually above the spray zone. Being surrounded by ocean, which never goes below 7 degrees C in the winter, island ecosystems such as Race Rocks often avoid the extremes of temperature that may be experienced in the winter in the rest of Canada.

See this reference for other examples of introduced garden varieties that have become established as escapes on Great Race Rocks.

Evening-scented Stock, Matthiola incana in December 2008. Calendula, (Calendula officinalis) also in December 2008.

5. There are rarely frosts at Race Rocks in the winter, whereas the rest of southern Vancouver Island has frequent temperatures several nights which dip below zero degrees C. killing off tender vegetation. These flowers remained growing throughout the winter in 2007-2008. The winter of 2008-2009 was more harsh with a week of freezing winds from the mainland, but plants on the West side of buildings continued blooming.

OTHER Publications on Strait of Juan de Fuca

U of Washington
Jan Newton is at the Washington state Department of Ecology and is interested in how the Straits affect Puget Sound. She has organized the “Joint Effort to Monitor the Straits,” which regularly sample the three stations south of San Juan Island in the map at . Click on the Station Group Puget Sound, and the Selected Station – Juan de Fuca.

Strait of Juan de Fuca TemperatureStrait of Juan de Fuca Temperature

Strait of Juan de Fuca Temperature


Recent Posts

Foggy week and dead gull chicks


These first days of August were pretty foggy:Everyday the fog was around Race Rocks from 3:00 AM to 9-10 AM and for the 2 last days it was all day long. One day was warm but the others not so much because of the wind. On the 6th the fog around the rock  was just like a thick wall…


No more Elephant Seals and slowly the Sea lions are coming back .We saw the first one on the jetty and 2 big stellers on middle were pretty noisy like usual.The 3 last days many dead gull chicks around and gulls are really aggressive (they attack you)…I saw an amazing show:2 eagles and 4 vultures hunting the chicks together (the 2 eagles going to a dive and the vultures staying at the same level in the air). Many pigeons guillemots . 2 beautiful and big cormorants spend a full day on the same rock. and 2 times we had orcas in Race Passage around 11:00 AM followed by so many boats!The second time some were almost on them (10 to 30 meters) …disgusting!


The sea water pump has been repaired and is working well now. Cleaning days before the shift.


Shift over done on the  6th in the afternoon. James got a full tour of the rock and has been introduced.



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