1874.

1875.

1876..

1877.

1878.

1879.

1880.

1881.

1882.

1883.

1884.

1885.

1886.

1887.

1888.

1889.

1890.

1891.

1892.

1893..

1891.

1895.

1896.

1897.

1898.

1899.

1874.

1875..

1876.

1877.

1878.

1879.

1880.

1881

1882.

1883.

1884.

1885.

1886.

1887.

1888.

1889.

1890.

1891.

1892.

1893.

1894.

1895. 1896..

1897.

1898.

1899.

Year.

Means (26 years)

Average (26 years)

MONTHLY AND ANNUAL MEAN TEMPERATURE (DEGREES FAHRENHEIT).

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

47.6

51.9

53.6

46.1

46.9

52.8

46.5

45.0

45.7

49.0

52.6

48.5
49.7

57.7

53.2

47.1

40.4 45.3

52.0

47.3

54.5 52.1 53.0 52.6

43.7

46.1

50.8

47.3

48.0 48.6

51.7

49.4 51.9

55.8

52.4

49.1

53.3

51.0

54.7

52.4

46.8 49.3 51.8 58.8 67.7 76.1 71.1 68.7 71.0 64.3 56.8 57.9
49.8 53.31 54.4 62.1 66.6 68.5 68.8 70.1 64.7 65.5 53.5 53.1
42.2 49.6 57.8
57.9 59.2 69.6 65.2 66.1 65.2 64.0 55.5
50.6 51.4 55.8
55.1 57.2 68.0 67.4 64.9 63.9 58.2 54.1
52.1 54.1 54.8 50.1 64.8 64.8 65.7 62.2 56.4 52.8
55.9 56.5 57.8 66.1 66.3 67.1 64.0 59.5
52.4
52.9 59.0 62.1 64.7 65.7 62.1 58.9
60.0 62.3 60.5
66.3 64.3 62.2 56.8
51.9 58.9 61.9
65.6 65.6 65.4 56.6
53.7 59.8 68.8 66.8 66.3 67.1 57.5
55.2 60.2 61.6 65.4 65.6 62.0
56.3 54.5
55,5 60.2 61.3 65.8 65.4 64.6 61.6 56.3
60.5 63.9 66.3 66.7 63.7 57.3 52.3
63.9 64.8 63.3
64.7 62.5
66.8 68.6 68.0 62.3
56.5 52.9
56.7 59.7
67.2 67.7 61.5
56.3
50.5
53.9 56.7
65.9 66.8 64.9 60.5 55.1 48.6
49.0
51.3 54.4 55.4
65.2 69.4 €9.4 65.4 61.9 56.5 48.2
50.7 52.5 54.9 54.5 61.4
62.7
66.0 66.8 64.2 60.0 55.8 50.3
47.7 50.0 53.1 54.4 58.7 61.1 65.8 i 65.7 62.0 58.6 55.5 52.3
47.3 48.6 49.8 57.6 60.8 62.1 67.6 67.7 67.6 61.0 57.0 50.0
48.7 53.6 53.5 56.8 60.2 66.2 66.6 67.3 64.0 62.1 55.0 49.3
49.0 54.8 56.1 53.4 59.4 75.2 69.3 65.7
62.7
62.0 52.2 51.2
47.6 49.8 48.5 59.5 I 62.6 65.8 68.2 65.6 64.8 58.5
51.4
45.4 53.3 51.8 57.7 57.0 65.3 65.1 65.2 63.1 61.1 55.0
56.4 52.2 54.7 59.1
58.4 67.8 67.4 65.5 66.0 60.4 57.6
48.2 50.7 53.6 56.4 60.1 65.5 66.7 66.4 64.7 60.2
54.1

50.3

48.2

54.8

54.3

58.6

54.6

50.5

46.4

52.6

52.8

58.3

59.8

65.2

47.6

50.9

61.9

66.2

66.1

45.0 48.7

63.5

63.6

60.0

47.6

46.3

50.4

50.1

2.61 2.75

4.08

0.77 2.83 0.87 0.21 0.00 0.00 0.00 0.10 1.81 1.91
0.41 0.39 0.00 0.00 0.45 0.00 0.00 0.00
3.41 3.11 0.41 0.25 0.00 0.00 0.00 0.08
0.00 0.00 0.00
1.48 0.02 0.00 0.00 0.00 0.48

2.23

0.48! 0.78 0.00 0.05! 0.00

5.53

1.48

1.52

2.12

3.18

3.68
0.18

1.83

0.86

2.11

3.59 1.12

0.08
0.00 0.00
1.51
1.35 0.02 0.00
0.37 0.85 1.87
6.94 2.22
0.80 0.76 0.97
3.18 5.85 1.24 1.58 0.06 0.00 0.00 0.00 0.87 1.79 2.99
1.34 0.96
3.66 0.67 0.00 0.00 0.00 0.00 0.00 0.49 5.60
2.04 0.80 1.28 0.00 0.12 0.00 0.00 0.02 0.45 0.88 1.83
1.17 1.49 4.26 1.10 0.55 0.00 0.00 0.00 0.04 0.87 1.32 0.82
3.86 0.94 2.70 0.66 2.18 0.00 0.00 0.00 0.09 0.67 0.28 0.37
6.23 3.38 0.05 2.15 0.00 0.00 0.08 1.50 0.06 3.90
2.75 0.11
T. 0.00 0.00 0.00 0.06 7.39
1.89 4.47 0.00 0.00 0.03 0.00 0.00 0.49 0.73 0.71
0.63 1.28 0.00 0.00 0.02 0.00 0.61 0.03 0.70 2.53
3.06 1.09 3.00 0.31
0.60 0.22 0.00 0.00 0.60 0.00 3.88 2.44
0.70
5.80 0.79 0.96 0.04 0.00 0.00 0.00 4.48 1.73 10.55
3.64 2.08 0.55 0.75 0.00 0.00 0.00 0.05 0.00 0.05 2.40
5.27 2.46 1.79 0.26 0.05 0.00 0.00 0.37 0.08 0.46 5.84
1.11 1.60 4.75 0.65 1.60 0.05 0.00 0.00 0.00 1.00 4.00 7.77
2.68 5.12
1.35 0.30 0.00 0.00
0.00
0.00 0.00 0.81 1.69
4.73 2.61
0.69 0.63 1.36 0.40 0.00 0.00 1.08 1.32 0.55 7.80
6.28 1.42 1.46 2.05 1.36
0.00 0.00 0.00 0.05 0.83 1.08 0.84
5.17 0.27 2.22 2.79
0.00 0.01 0.74 0.32 1.30 2.82 2.55
1.68 3.43 2.64 0.91
T.
0.00 0.00 0.21 1.01
0.37 1.20
0.93 1.93 0.52 0.20
0.06 0.00 0.00 1.13 0.61 0.45 0.44
0.21 4.17 0.48
T. 0.00 0.00 0.00 3.26 2.70
1.43
2.22 2.63 1.35
0.14
0.03
0.89

0.68

6.81

0.50

6.52

0.55

2.95

0.44
0.16

0.44
0.65

1.88

2.77

0.56

0.20

1.39

T.

2.70

Annual.

61.7

60.9

58.3

58.2

56.5

57.6

55.5

57.9

55.2

56.7

56.8

58.3

57.6

57.5

59.2

59.4

57.8

58.8 58.3

57.1 58.1

58.6

59.2

57.5

57.2

59.7

58.1

11.19

5.51

12.71 6.63 19.20 19.04 14.24 9.54 11.62 11.75 24.21 15.29 13.03 13.29 15.20 25.55 16.04 17.13 22.53 14.90 21.17 15.37 18.63 11.61 6.71 14.78

14.88

[Lick Observatory.]

The director of the Lick Observatory, Dr. Wallace W. Campbell, has kindly placed at the disposal of the Weather Bureau the observations made at Mount Hamilton by different members of the observatory staff from 1888 to 1900. The following named gentlemen have at various times acted as observers: Charles B. Hill, A. J. Burnham, H. K. Curtis, A. O. Leuschner, A. L. Colton, C. D. Perrine, R. G. Aitken, W. H. Wright, H. K. Palmer, E. F. Coddington, and A. J. Cloud.

The observatory is situated on Mount Hamilton, a peak in the Coast Range, in Santa Clara County. The elevation of the station is 1,283 meters (4,209 feet) above sea level. The observatory is situated in latitude 37° 20′ 25.6" north, longitude 121° 38′ 4.22" west. The mountain is about 14 miles in an air line directly east of the city of San Jose.

The records for temperature at Mount Hamilton cover a period of twelve years and for precipitation twenty years. The mean annual temperature is 52°. The coldest month is January, with a mean temperature of 39.7°, and the warmest month is July, with a mean temperature of 69.4°. The highest temperature recorded is 94°, on July 1, 1891, and the lowest 13°, on February 4, 1899.

1889.. 1890.

1891.

1892.

1893.

1894.

1895.

1896.

1897.

1898.

1899.

1900.

Rain falls in every month of the year, but in July and August the showers are light and infrequent. The mean annual precipitation is 32 inches, which, it is interesting to notice, is more than double that of San Jose, where the mean, based upon records covering twenty-six years, is but 14.88 inches. The ratio of the rainfall on the mountain to that in the valley appears to be fairly constant for all months in the year. December is the month of heaviest precipitation on the mountain. More than half of the annual rainfall occurs in the four months of December, January, February, and March. The annual precipitation has exceeded 30 inches during eight years of the twenty, and has fallen below 20 inches during two years. These dry years were 1885, when the rainfall amounted to but 18.23 inches, and the memorable 1898, when but 17.11 inches fell. The years of maximum rainfall were 1884, when 90.12 inches fell, and 1894, when 44.49 inches fell.

MAXIMUM TEMPERATURES (DEGREES FAHRENHEIT).

MOUNT HAMILTON.

72

1893

58

74

54

64

67

60

65

61

74

1893

64

59

66

62

64

64

66

60

68

67

68

1899

a Also other years.

84 1892

Absolute minimum and year.

Year.

Mean (12 years)

Average (20 years).

a 1890

22

18

21

25

32

25

21

27

13

24

13

1899

31

25

26

18

19

21

25

31

18

1896

30

31

29

26

25

25

24

28

27

26

28

24 a 1895

a Also other years.

26 1899

MONTHLY AND ANNUAL MEAN TEMPERATURE (DEGREES FAHRENHEIT).

41 1899

MONTHLY AND ANNUAL PRECIPITATION (INCHES AND HUNDREDTHS).

:

35.9

39.5 43.9 44.8 50.3 52.8 67.4 70.7 70.4 66.9 50.5 48.5 35.2
30.2 36.8 40.5 47.6 54.5 57.6 59.8 68.9 65.9 58.1 55.5 45.7
41.6 35.0 41.0 44.3 51.4 55.5 70.9 71.5 60.7 58.7 51.8 35.8
43.6 41.7 42.6
42.3 52.6 57.3 66.9 70.8 62.1 53.2
49.7 39.8
36.0 37.7 37.3 40.5 51.9 58.8 67.9 71.8 55.4 51.0 47.0
45.0
35.61 40.4 49.4 51.6 52.6 71.3 71.4
63.5 55.5 57.5 37.2
36.4
45.6 42.8 47.2 52.2
65.2 67.2 70.4 59.0 59.9 47.9 41.4
45.2 46.5 43.4 37.6 46.6 64.6 73.2 67.8
61.7 57.8 44.7 45.4
42.1 36.4 32.6 51.0 58.0 57.8 70.8 71.5 59.4 45.9 45.3
42.9
35.7 42.8 39.1 50.8 47.9 62.0 71.4 71.2 61.8 56.0 46.5 43.3
42.5 41.0 39.6 47.6 46.3 63.7 71.6 61.3 69.8 50.2 46.9 45.6
47.5 43.0 48.1 43.0
52.9 63.8 71.6 62.1 56.3 51.6 51.1 47.2
39.7 40.5 41.0 46.0 51.6 60.5: 69.4 69.1 61.9 54.0 49.4

42.0

18 1896

0.33

0.91

9.72

5.60

1.99

4.40

1.04

7.93

1.38

3.51 5.99 1.13 0.98 0.09 0.33 0.00 0.00 0.10
3.55 2.90 5.40 4.70 0.48 1.06 0.00 0.00 0.00 6.16 3.45 1.93
i
3.10 3.75 8.66 2.66 7.55 0.00 0.00 0.00 0.65 2.15 1.48 2.05
12.76 16.35 11.96 1.24 3.85 0.00 0.15 0.65 3.71 0.01 33.84
0.57 1.15
2.08 0.16 0.36 0.00 0.00 0.15 0.05 1.92 9.80
1.80 5.77 6.79 0.70 0.00 0.00 0.00 0.00 0.60 2.82 2.34
2.83 7.80 1.39 5.75 0.25 0.30 0.04
0.00 0.33 0.09 0.90 11.25
10.04 1.38 3.40 0.68 1.25
0.67
0.00 0.02 0.49 0.03 3.27 4.23
1.42 6.17 1.92 3.21 0.05 0.00 0.00 0.00 4.38 4.46 13.19
6.60 4.39 1.79 2.42 0.00 0.00 0.00 0.80 0.02 0.58
5.39
7.12 4.10 3.08 1.01 0.57 0.00 0.00 0.28 0.61 0.38 9.54
2.99 5.98 1.90 3.52 0.32 0.00
T.
0.24 1.38 10.30 5.56
3.29 3.45 8.99 3.61 0.95
0.16 0.00 0.00 0.48 0.66 4.01 3.58
9.74 10.52 2.54 0.89 2.78 0.64 0.02
T. I 1.64 2.98 0.84 11.90
10.00 3.08 1.46: 2.30 2.39 0.00 0.01
3.16
1.08 T 3.83 6.70 2.10 0.02
T. 0.28 0.47 1.85 5.86
7.42 6.45 0.82 0.28 0.38 0.00 0.00 0.07 1.25 1.51
4.16 2.01 0.84 2.41 0.38 0.00 0.00 0.29 1.33 1.23
0.75 11.11 1.40 1.47 0.39 0.00 0.12
T. 6.37 4.92
1.70 3.37 4.06 1.35
Ꭲ . 0.01 0.02 0.08 3.48 7.76
1.78 0.47
T. 0.03 0.34 1.91 2.95

1.97

0.00: 0.08 0.78 2.46

9.54

4.91

3.50

2.70

2.30

5.63

2.13
4.16
2.21

3.26

4.73

4.36

5.18 3.25

7.18

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. Annual.

1891

53.4 51.8 51.5 51.9

50.0 51.8

52.9

52.9

51.2

52.4

52.2

53.2

52.1

23.09 29.63 32.05 90.12 18.23 25.22

30.93 25.46 35.84

29.92

28.07

34.16

29.18

44.49

25.72

36.64

24.38

17.11

36.32

27.30

32.19

MEAN RELATIVE HUMIDITY (PER CENT).

Jan. Feb. Mar. Apr. May. June. July.

61.1
60.8
52.4

37.1

70.7

77.7 77.2 62.0 65.8 57.4 61.0 66.7 55.6 56.8
47.9
44.7 57.8 64.4 62.3
48.8 46.3 54.5 81.1 84.9 67.6
67.9 41.9 33.1 48.8 61.7 48.2
44.6
55.7 50.2 53.0 58.0
38.1 42.1 52.5 52.7
56.7 31.0
36.8 51.9 61.3
67.6 57.5 30.3 38.2 53.2 57.6
66.7 45.4 33.9 54.0 40.2 67.8
65.5 49.7 39.9
63.6 52.1

39.9

69.1

76.9 87.4 73.4 57.1
79.2 80.7 72.3 56.8 72.8
82.2 59.8 73.0 64.5 58.5
72.2 52.7 78.3
84.2
70.5 88.3
90.9
77.9 72.7 74.1
61.4 83.2 64.8
66.1 68.5 73.0
76.9
69.3 72.5
78.9 67.4

53.9

51.4

63.9
57.3

54.7

70.6

78.6

41.1

Highest monthly mean humidity 91.2, February, 1891.
Lowest monthly mean humidity 30.3, July, 1898.

91.2

Aug. Sept. Oct. Nov. Dec.

12,098 9,260 7,837
8,035 9,987 9,655 10, 350 8,102
9,796
9,883 12, 011 10, 495
7,860
8,824 10, 105 8, 635
11,068 | 10, 166 11, 703
8,811 10, 953 10, 644
9,307 10, 219 10,791

46.7

55.8

6,881 6, 195 6,865 6,976 7,493 7,215

6,519
6,705
6, 333
7,386
8, 644 8,033 7,604
8,106 7,086 6,856
9, 371 7,784 6,900 6, 938

62.1

62.4

11, 550

4,974
9,229 9,541
10, 238
9,997
8,838 12,068
10, 390
8,500
8,034 7,296
8, 617 9,825

83.4 72.7 65.3

87.4

65.2

66.6

62.8

56.3

67.4

69.7

10,823 12, 183 9,832 11, 838

12,236 10, 002 11,152

a Seven days' record missing (15th to 21st). NOTE.-November 16-17, 1893, maximum hourly velocity, 80 miles; velocity of gusts probably over 100 miles. January 15, 1895, highest hourly velocity (estimated), 80 to 90 miles.

[Data from records of Southern Pacific Railway Company.]

Aptos is situated in Santa Cruz County, on Monterey Bay, about 7 miles southeast of the city of Santa Cruz, in latitude 36° 58′ north, longitude 121° 54' west; elevation 102 feet above sea level.

LOCAL CLIMATOLOGY.

The mean annual temperature, based upon records covering sixteen years, is 56, which is practically the same as that of San Francisco, and 2.4° lower than the annual mean at Santa Cruz. June, July, and August are the warmest months, with mean temperatures of 62.5°, 62.3°, and 61.4°, respectively; September is also a warm month, with a mean of 60.9°. The coldest month is January, with a mean of 48.5°; the means for February and December are nearly the same. The maximum seldom exceeds 90°, the highest recorded in recent years being 91°, in June, 1898. Minimum temperatures of 26° are recorded in January, 1898, December, 1900, and February, 1901.

1885. 1886.

1887.

1888.

1889.

1890.

1891.

1892.

1893.

1894.

1895.

1896.

1897.

1898.

1899.

1900.

The average annual precipitation during the past sixteen years is 25.63 inches, about 1 inch less than that of Santa Cruz. The greatest precipitation occurs in December and January, but heavy rains also fall in November, February, and March. The rainfall during June, July, August, and September is very light and infrequent. During the month of December, 1889, the rainfall was 18.29 inches, and the total of that year was 37.94 inches.

MONTHLY AND ANNUAL MEAN TEMPERATURE (DEGREES FAHRENHEIT).

Year.

Mean (16 years)

APTOS.

Jan. Feb. Mar. Apr.

May. June. July. Aug. Sept. Oct. Nov. Dec. Annual.

53.1 49.2 54.1 52.3 54.4

48.6

46.2

49.1

49.7

50.9

49.2 51.1 55.4 57.7 61.7 65.4 64.9 63.5 60.2 59.3 56.0 53.7
51.0 54.8 52.3 56.6 59.3 58.9 61.4 61.9 60.9 55.1 51.6
49.1 47.0 55.5 55.7 58.9 63.4 61.0 60.1 60.1 59.6 54.5
46.0 51.9 53.0 58.4 59.7 67.9 65.9 63.2 61.8 59.1 53.9
51.6 56.6 59.7 59.6
62.5
63.4
61.9
62.9 60.7 56.8
49.0 53.6 56.2 61.0 61.9 62.0 62.6 61.2 59.3 55.0
53.9 55.5 57.9 63.5 62.8 62.6 62.4 57.8 55.2 47.8
53.8 55.4 61.3 63.2 69.2 63.4 60.7 58.3 53.0 50.2
51.8 51.6 58.8 59.5
59.5 60.7 60.5 57.3 54.5 52.4
48.2
52.1
55.8 57.1 61.9 i 63.9 64.3 63.1 56.0 51.1 46.9
44.8 47.8
48.4 50.0 55.1 56.5 57.9 56.8 66.0 57.5 51.3 44.0
44.9 47.9 47.0 52.3 54.6 60.2 62.7 60.3 54.0 52.7 45.8 44.6
42.0 45.1 47.9 61.1 63.4 72.7 63.6 60.8 64.1 59.5 51.1 48.1
56.8
48.7 50.4 44.9 55.4 62.6 60.9 59.8 58.81 58.1. 50.8
44.9
51.8 47.4 51.6 56.2 55.0 59.9
58.9 60.3 58.0 54.8 53.0 49.7
48.8 51.5 54.2 51.9
61.9 59.6 59.0 60.7 60.2 59.6 55.2 49.3
49.5
54.9 58.8 62.5 62.3
60.9 57.8 53.0 49.7

52.8
47.4

51.1

45.6

48.5

52.3

61.4

123

58.2

56.4

56.2

57.9

58.0

56.9

56.5

57.7

55.4 55.5

53.0

52.3

56.6 54.4

54.7 55.7 56.0