PHYSICAL FEATURES AND NATURAL RESOURCES

CLIMATE

CLIMATE. Season.

[This Section on " Climate" was supplied by the Meteorological Department of the Government of India, Poona.]

CLIMATE .-The climate of the district though moist is generally healthy. The rainfall is plentiful and regular. The year may be divided into four seasons, the summer season from March to May, the south-west monsoon season from June to September, the post-monsoon season from October to November and the winter season from December to February.

Rainfall.

Records of rainfall in the district, for about 80 years are available for 18 rain-gauge stations. Tables No. 1 and 2 give the rainfall data for the individual stations and for the district as a whole and frequency of annual rainfall. The Amboli station which is at the foot of the Western Ghats gets a rainfall nearly twice as much as at some other stations in the district. As this rainfall is not quite representative of the conditions prevailing in the district as a whole except the areas at the foot of the ghats, the data of this station is not included for calculating the district averages. The monsoon bursts over the district generally by the beginning of June and the rains continue with little intermission till about the middle of October. The average annual rainfall for the district as a whole is 3,188 mm. (125.52"). The rainfall increases rapidly from the coast towards the Western Ghats on the eastern border of the district. In and near the Ghats rainfall is very heavy. Amboli gets annually on an average 7,446 mm. (293.1") of rain. The coastal stations of Malvan and Deogad get annually 2,155 and 2,247 mm. (84.9" and 88.5") of rain, respectively. Practically the entire annual rainfall occurs during the months from June to October. July is the month with highest rainfall when about one-third of the annual rainfall is received. The variation from year to year in the rainfall is not large. During the 50 year period from 1901 to 1950, the year 1931 was one with the heaviest rainfall amounting to 143 per cent. of the normal. Rainfall amounting to only 58 per cent. of the normal occurred in 1941, the year with the lowest rainfall. During the fifty year period there were six years with less than 80 per cent. of rainfall, and none of them were consecutive. Considering individual stations, Malvan, Dapoli and Mandangad had one occasion each of two consecutive years of low rainfall. Guhagar had four consecutive years, from 1904 to 1907, when rainfall was less than 80 per cent. of the formal. It will be seen from Table No. 2 that in 41 out of 50 years, the rainfall in the district was between 2,600 and 3,800 mm.

On an average for 101 days in the year the district gets 2.5 mm. (10 cents) or more of rain. As in the case of the amount of rain-tall the number of rainy days is less near the coast than in the eastern portion of the district near the Ghats.

The heaviest rainfall in 24 hours which occurred at any station in the district, was 535.4 mm. (21.08") at Dapoli on June 3, 1882.

Temperature.

Meteorological data are available for four stations in the district, viz., Harnai, Ratnagiri, Deogad and Vengurla. Being a coastal district the variation of temperature during the day and through the seasons is not large.

In the hot season temperature rises slowly from March, and May is the hottest month. With the onset of the monsoon, temperature drops by three to four degrees. Day temperatures during the monsoon are lower than those in the cold season. In the post monsoon months of October and November, day temperatures increase and days in November are as hot as in May. Night temperatures are the lowest in January. Areas within 20 to 25 kilometres of the coast are the most pleasant particularly in the hot months with the sea breeze blowing, nearly throughout the day. Further inland during the hot months both days and nights can be oppressive and more so in the tract at the foot of the Western Ghats. Along the coast the maximum temperature rarely goes beyond 38°C (100.4°F) but in the interior may reach 40° or 41°C (104°0 or 106°0 F).

Humidity.

Owing to the proximity of the sea, the district is on the whole very humid. Even during the winter and summer the relative humidity seldom goes below 50 per cent.

Cloudiness.

During the monsoon, skies are heavily clouded to overcast. But in the rest of the year skies are clear or very lightly clouded.

Winds.

Winds are very strong and are mainly westerly or south westerly during the monsoon. In the rest of the year winds blow from directions between north and east in the mornings and between west and north-west in the afternoons.

Special weather phenomena.

During the pre and post monsoon months the district experiences very strong winds sometimes reaching gale force particularly near the coast and heavy rain in association with cyclonic storms which develop in the Arabian Sea and move in close proximity to the coast. Thunderstorms are common in the post monsoon months and the latter part of the hot season.

Tables No. 3, 4 and 5 give the temperature and humidity, mean wind speed and frequency of special weather phenomena respectively for Ratnagiri. (The meteorological conditions at Harnai, Deogad and Vengurla are not appreciably different from those at Ratnagiri. The data for Ratnagiri only has therefore been included.)

TABLE 1.

NORMAL AND EXTREMES OF RAINFALL IN RATNAGIRI DISTRICT. (1950- 51).

(a) Normal rainfall in mm.

(b) Average number of rainy days (days with rain of 2.5 mm. or more).

*Based on all available date

** Years given in brackets

TABLE 2.

(1901-1950)

FREQUENCY OF ANNUAL RAINFALL IN RATNAGIRI DISTRICT.

Temperature and Humidity.

TABLE 3.

MAXIMUM AND MINIMUM TEMPERATURE AND RELATIVE HUMIDITY IN RATNAGIRI DISTRICT.

*Hours I. S. T.

Winds.

TABLE 4.

MEAN WIND SPEED IN RATNAGIRI DISTRICT.

Special Weather Phenomena.

TABLE 5.

THUNDER, HAIL, DUST-STORM, SQUALL AND FOG IN RATNAGIRI DISTRICT.

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