This report describes the historical weather record at the Adelaide International Airport (Adelaide, Australia) during 2013. This station has records back to February 1955.
Adelaide has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (43%), croplands (19%), grasslands (18%), forests (10%), and built-up areas (8%)
Daylight saving time (DST) was observed at Adelaide during 2013. There were two time changes during 2013:
2013 was not a leap year, so it has 365 days and no February 29th. The first leap year before 2013 was 2012 and the first after was 2016.
The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 2013 they occurred on:
|Spring Equinox||Sunday, 22 September 2013.|
|Summer Solstice||Saturday, 21 December 2013.|
|Fall Equinox||Wednesday, 20 March 2013.|
|Winter Solstice||Friday, 21 June 2013.|
The hottest day of 2013 was January 4, with a high temperature of 111°F. For reference, on that day the average high temperature is 81°F and the high temperature exceeds 94°F only one day in ten. The hottest month of 2013 was January with an average daily high temperature of 82°F.
Relative to the average, the hottest day was January 4. The high temperature that day was 111°F, compared to the average of 81°F, a difference of 30°F. In relative terms the warmest month was September, with an average high temperature of 69°F, compared to an typical value of 65°F.
The longest warm spell was from March 1 to March 13, constituting 13 consecutive days with warmer than average high temperatures. The month of March had the largest fraction of warmer than average days with 61% days with higher than average high temperatures.
The coldest day of 2013 was June 19, with a low temperature of 37°F. For reference, on that day the average low temperature is 46°F and the low temperature drops below 39°F only one day in ten. The coldest month of 2013 was June with an average daily low temperature of 48°F.
Relative to the average, the coldest day was December 15. The low temperature that day was 48°F, compared to the average of 59°F, a difference of 11°F. In relative terms the coldest month was November, with an average low temperature of 54°F, compared to an typical value of 56°F.
The longest cold spell was from November 8 to November 19, constituting 12 consecutive days with cooler than average low temperatures. The month of November had the largest fraction of cooler than average days with 77% days with lower than average low temperatures.
The clearest month of 2013 was June, with 10% of days being more clear than cloudy.
The cloudiest month of 2013 was July, with 58% of days being more cloudy than clear. The longest spell of cloudy weather was from May 31 to June 9, constituting 10 consecutive days that were cloudier than they were clear.
This station provides hourly reports of significant weather events at and around the station, but does not report the quantity of precipitation at the station itself. This is common for weather stations located outside of the United States, and for a small subset of stations in the United States that are located at lesser used and smaller airports.
This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.
The day in 2013 with the most precipitation observations was July 6. There were 24 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was July, with 297 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from February 2 to February 15, constituting 14 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was January, with 84% of days reporting no observed precipitation at all.
The month with the largest fraction of days with at least some observed precipitation was August, with 74% of days reporting some observed precipitation.
In this section we consider only those weather reports that indicate liquid precipitation. For the purposes of this analysis, we include thunderstorms even though some thunderstorms are not accompanied by liquid precipitation.
The month of 2013 with the largest number of those reports was July, with a total of 283 reports. The day with the largest number of those reports was July 6, with a total of 24 reports.
This station reports when snow is observed falling but does not report the quantity of snow that has fallen or the depth of snow on the ground.
In this section we consider hourly weather reports that contain an observation of falling snow. These reports do not necessarily correspond to accumulation.
The first reported snow fall in 2013 was on July 19; the last was on October 17. The month of 2013 with the largest number of those reports was July, with a total of 14 reports. The day with the largest number of those reports was July 20, with a total of 9 reports.
Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.
When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 2013 was January with an average daily low humidity of 29%, and the most humid month was June with an average daily low humidity of 61%.
But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.
Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.
Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.
To take some examples, and basing our categorization on the daily high dew point in 2013, January had 3 dry days, 26 comfortable days, and 2 humid days; April had 4 dry days, 26 comfortable days, and no humid days; July had 13 dry days, 18 comfortable days, and no humid days; and October had 12 dry days, 19 comfortable days, and no humid days.
The highest sustained wind speed was 40 mph, occurring on September 26; the highest daily mean wind speed was 23 mph (October 2); and the highest wind gust speed was 56 mph (September 30).
The windiest month was October, with an average wind speed of 13 mph. The least windy month was June, with an average wind speed of 9 mph.
Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.
The day of 2013 with the lowest average visibility was October 9, with an average visibility of 0.6 mi. The month with the lowest average visibility was February, with an average visibility of 5.6 mi. With an average visibility of 6.2 mi, the month of December had the highest average visibility.
The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.
The day of 2013 with the lowest average cloud ceiling was June 18, with an average cloud ceiling of 80'. The month with the lowest average cloud ceiling was August, with an average cloud ceiling of 5424'. The month of February has the highest average cloud ceiling, with an average cloud ceiling of 12524'.