224 
mb. a. w. preston’s meteorological notes. 
December. 
This month will long be remembered on account of its extra- 
ordinary severity. The mean temperature was 30.2 degrees, or 
about 9 degrees below the average; there were only two nights 
throughout the month on which it did not freeze, and there were 
only five days on which the temperature exceeded 40 degrees. 
At Greenwich the mean temperature was lower than in any 
December since 1788. Further details as to the exceptional 
character of the frost will be found in a supplementary paper. 
The falls of snow were at no time so heavy as in November, but 
the ground was covered in a white mantle from the 15 th to the 
end of the month without a day’s intermission. Christmas Day 
was one of those known as the “ old-fashioned ” sort, and it is 
many years since such an one had been experienced. 
The Seasons. 
The following tables show the mean temperature and rainfall for 
the four seasons, together with those of the four previous years, 
and of a twenty-year approximate average : — 
TEMPERATURE. 
Seasons. 
1886. 
1887. 
1888. 
1889. 
1890. 
20- year 
average. 
Departure 
of 1890 from 
average. 
Winter (Dec. to Fob.)... 
Spring (Mar. to May) ... 
Summer (June to Aug.) 
Autumn (Sept, to Nov.) 
degrees. 
35.5 
46.5 
59.5 
52.0 
degrees. 
35.8 
43.3 
61.4 
46.9 
degrees. 
35.5 
43.5 
57.7 
49.3 
degrees. 
37.4 
46.5 
59.9 
49.2 
degrees. 
38.9 
46.8 
58.6 
50.2 
degrees. 
38.7 
47.5 
61.3 
50.0 
degrees. 
+ 0.2 
— 0.7 
— 2.7 
+ 0.2 
Year 
48.2 
47.0 
46.9 
48.0 
48.0 
49.4 
- 1.4 
RAINFALL. 
Seasons. 
1886. 
1887. 
1888. 
1889. 
1890. 
20-year 
average 
Departure 
of 1890 from 
average. 
Winter 
Spring 
Summer 
Autumn 
in. 
4.18 
5.35 
6.70 
6.23 
in. 
5.83 
5.14 
4.04 
7.68 
in. 
4.42 
5.83 
8.52 
7.00 
in. 
4.14 
7.09 
9.57 
8.94 
iu. 
4.80 
5.14 
9.61 
6.87 
m. 
6.45 
5.15 
7.10 
8.50 
in. 
- 1.65 
— 0.01 
+ 2.51 
— 1.63 
Y ear 
25.23 
20.52 
25.65 
29.82 
25.96 
27.20 
— 1.24 
