Seasonal Light and Temperature Variation

Contact
Seasonal light and temperature variation is related to the solstices and equinoxes, which have variable dates and times, that are determined by the movement of the Earth about the Sun.

Daily temperature has more effect on me than the amount of daylight and the solstice times did not seem to give a very good indication as to the middle of summer or winter in temperature terms.

Complete temperature data was obtained for the years 1856 to 1997 (total 142 years), to determine the temperature turning points for both summer (the hottest day) and winter (the coldest day) for Melbourne, Australia and Toronto, Canada.

Both graphs show relative, rather than actual values, with the maximum as 1, the minimum as -1 and the average value as zero (the horizontal axis). The hottest and coldest days were determined from a curve of best fit on paper.
Melbourne, Australia (Southern Hemisphere):

Latitude:  37° 52' South

Click on graph for enlarged image
Data provided by the Bureau of Meteorology.

Melbourne Seasons Graph

The zero values of the Amount of Daylight Graph, represent the equinox days where day and night are approximately of equal length ie. 12 hours.  In spring that is most often September 23, and in autumn is most often March 21.

The zero values on the Daily Average Temperature Graph approximate the average annual temperature (midrange) days that occur in spring on ~October 24, and in autumn on ~April 21.

It is interesting to note that the coldest day comes basically in the middle of the calendar winter in Australia, which starts on June 1 and ends on August 31.

Frequency of AEST dates for the 142 year period (calculated using GMT values obtained from the Nautical Almanac Office):

March Equinox
Autumn

June Solstice
Winter

September Equinox
Spring

December Solstice
Summer

Mar 20

28

 

Jun 21

50

 

Sep 22

1

 

Dec 21

11

Mar 21

106

 

Jun 22

90

 

Sep 23

100

 

Dec 22

108

Mar 22

8

 

Jun 23

2

 

Sep 24

41

 

Dec 23

23

Monthly, and overall, maximum and minimum temperature values for the 142 year period.

Month

Maximum Temperature

Minimum Temperature

 

Average

Highest

Lowest

Average

Highest

Lowest

January

25.7

45.6

14.6

14.0

28.8

5.5

February

25.6

43.2

14.7

14.4

30.5

4.5

March

23.7

41.7

12.0

13.0

26.3

2.8

April

20.2

34.9

8.9

10.6

22.2

1.5

May

16.5

28.7

8.3

8.5

17.1

-1.1

June

13.9

22.4

5.3

6.7

14.8

-2.2

July

13.3

23.1

4.4

5.8

14.3

-2.8

August

14.8

26.5

0.0

6.5

16.2

-2.1

September

17.0

31.4

0.0

7.7

22.7

-0.5

October

19.5

36.9

9.0

9.3

24.1

0.1

November

21.8

40.9

11.0

11.0

26.2

2.5

December

24.1

43.7

10.4

12.7

26.6

4.4

Total Period

19.6

45.6

0.0

10.0

30.5

-2.8

Toronto, Canada (Northern Hemisphere):

Latitude:  43° 40' North

Click on graph for enlarged image

Data provided by Environment Canada

Toronto Seasons Graph

The zero values of the Amount of Daylight Graph, represent the equinox days where day and night are approximately of equal length ie. 12 hours. In spring that is most often March 20, and in autumn is most often September 23.

The zero values on the Daily Average Temperature Graph approximate the average annual temperature (midrange) days that occur in spring on ~April 22, and in autumn on ~October 26.

Frequency of EST dates for the 142 year period (calculated using GMT values obtained from the Nautical Almanac Office):

March Equinox
Spring

June Solstice
Summer

September Equinox
Autumn

December Solstice
Winter

Mar 19

4

 

Jun 20

13

 

Sep 22

50

 

Dec 21

78

Mar 20

102

 

Jun 21

110

 

Sep 23

90

 

Dec 22

64

Mar 21

36

 

Jun 22

19

 

Sep 24

2

 

 

 

Monthly, and overall, maximum and minimum temperature values for the 142 year period.

Month

Maximum Temperature

Minimum Temperature

 

Average

Highest

Lowest

Average

Highest

Lowest

January

-1.3

16.1

-23.9

-8.6

7.3

-32.8

February

-1.1

14.4

-25.0

-8.6

7.6

-30.6

March

3.3

26.7

-15.6

-4.2

11.7

-26.7

April

10.7

31.2

-5.5

2.0

20.0

-15.0

May

17.6

34.4

3.3

7.6

21.7

-3.9

June

23.3

36.7

8.3

13.0

24.4

0.0

July

26.3

40.6

14.4

16.0

25.6

6.7

August

25.2

38.9

13.9

15.3

25.0

4.4

September

20.8

37.8

7.2

11.5

24.4

-1.7

October

13.9

30.0

-0.6

5.7

17.8

-7.2

November

6.8

23.9

-15.0

0.4

14.4

-20.6

December

1.0

19.9

-19.4

-5.4

10.6

-30.0

Total Period

12.3

40.6

-25.0

3.8

25.6

-32.8

© Knowledge Evolution 2000-2017
All rights reserved
top