PHYSICAL FEATURES AND NATURAL RESOURCES

CLIMATE

THE CLIMATE OF THE KOLHAPUR PLAIN is temperate and similar to the other districts of Bombay Deccan adjoining the ghats. In the western part of Kolhapur near the Sahyadris it is always cooler than that in the eastern part which is liable to hot winds during April and May. The nights over the whole district are generally cool due to the influence of the sea breezes which set in during the afternoons and continue till late in the evening.

The year in respect of Kolhapur district may be divided into three periods as follows:-hot weather period from March to May; rainy period from June to October; and cold weather period from November to February.

There is only one observatory in the district located at Kolhapur, which maintains temperature and related meteorological records. The data available in another observatory in the neighbourhood at Miraj have also been utilised in describing the climate of the district. Table 1 gives the mean daily maximum and minimum temperatures and relative humidity for the city of Kolhapur based on available data (1949-58).

Hot Weather Period (March to May).

There is a rapid rise in temperature in March, reaching the maximum in April. April is the hottest month of the year, with an mean maximum temperature of 99°F. The corresponding figures for March and May are 96 °F. and 95 °F. respectively. Daily maximum temperatures exceeding 100°F. are fairly frequent in April. On an average there are 12 such days. The highest temperature recorded at Kolhapur during the last decade is 107°F. Temperatures exceeding 110°.F. are unlikely in this district. The mean daily maximum: temperature varies from 66 °F. to 72 °F. The diurnal variation of temperature is large and the mean value ranges from 30.7°F. in March to 22.7°F in May.

On individual days a range of 35°F. in March is not uncommon. The mean relative humidity in (March to May) this period is 65 per cent, in the morning and 35 to 40 per cent, in the evening. Low values of humidity of the order of 15 to 20 per cent, occur in these months in the afternoon. The prevailing wind direction is mainly westerly though in the afternoons of March, and April, easterly winds occur on about 50 per cent, of the days. The temperature is high during the day but the evenings are cooled by sea-breezes and the nights are not oppressive.

This is also a season of thunderstorm. At Kolhapur, one day in every three or four days in April and May, is a day of thunder. The rainfall in this season is accompanied by thunderstorms and it is about 1" in April and 1½" in May. This period accounts for about 10 per cent, of the total annual rainfall.

Wet Weather Period. (June to October).

The normal period of the onset of the South-West monsoon in the district is the first week of June. With the onset of the monsoon there is a rapid fall in the day temperatures and conditions of near uniformity over wide areas are reached in the months of July and August. The mean daily maximum temperature for July and August is 79 °F. Towards the end of September temperatures again begin to rise. The moisture content of the atmosphere in this season is very high and the air is nearly saturated on several days. The mean relative humidity for June to September is 87 per cent, in the morning and 77 per cent, in the evening. The direction of winds during this period is mainly westerly. There is a complete changeover in October when the winds are mainly from North-East to East. The annual rainfall varies widely in the district from 20" in the North-East to 250" in the west. This is the main rainy-season. A fuller account of rainfall is given in tables No. 2 and No. 3.

Winter (November to February).

Although day temperature remains higher than in the monsoon, the mean minimum temperature is the lowest and it ranges from 58° to 61 °F. December and January are the coldest months of the year. The district lies in an area where the lowest temperature on individual days may go down to 45⁰ F. Dry wind blasts during the period and the daily range of temperature is rather large. The mean daily range of temperature in December and January is 28°F. On individual days it may be even 35°F. The mean relative humidity for the season at Kolhapur is 63 per cent, in the morning and 33 per cent, in the evening. Low humidities less than 20 per cent, are not infrequent. Rainfall in November is about 1½ to 2". The rest of the period is practically dry.

RAINFALL.

Table 3 gives the average monthly and annual rainfall of eight rain recording stations in the district. Six of them are based on data of about 50 years (1901 to 1950) and two on about 17 years (1934 to 1950).

The average annual rainfall in the district varies widely from about 20" in Kurundwad-Shirol area in the north-east to over 240" in Gaganbavada area near Sahyadri in the west. Kurundwad has the lowest annual average of 19" whereas Gaganbavada gets 244". The isohyets (line of equal rainfall) practically runs from north to south. About three-fourths of the district receives more than 40" annually.

The district gets rain from the south-west as well as the north-east monsoons. Throughout the district rain falls from May to November. However, the main rainy-season is from June to October. It may be observed that during May and November rainfall over the whole district is nearly uniform, being about 1½" to 2". The normal period of the onset of the south-west monsoon is the first week of June. The portions to the west of Ratnagiri-Gaganbavada receive 90 to 95 per cent, of the annual rainfall in the months of June to September from the south-west monsoon winds. The percentage decreases in the north-west near Kurundwad to about 60 per cent, of the annual. If October is also considered, June to October accounts for over 80 per cent, of the annual rainfall in the district and for as much as 98 per cent, in the extreme west. The months of October to December account for 15 per cent, to 20 per cent, of the annual in the eastern portions of the district.

July is the month of maximum rainfall throughout the district. Thirty-five per cent, to 40 per cent of the annual rainfall is received in this month over a good portion of the district.

Table 4 gives the frequency distribution of annual rainfall. The highest and lowest values in a fifty-year period have not exceed twice or fallen to less than 50 per cent, of the average.

Gaganbavada near the Sahyadris recorded 323" in 1908 while Kurundwad in the north-east got less than 10" in 1905. The extreme north-eastern part is a semi-arid area with high variability of annual rainfall. 1905 was generally a year of low rainfall for the whole district.

TABLE SHOWING MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURES AND HUMIDITY FOR THE CITY OF KOLHAPUR.

(The means are based on data for the years 1949 to 1958).

TABLE No. 2.

PERCENTAGE OF WIND FREQUENCIES BASED ON 5.YEAR DATA (1952.57).

continued..

TABLE No. 3.

MEAN RAINFALL DATA IN KOLHAPUR DISTRICT (IN INCHES).

continued..

TABLE No. 4.

FREQUENCY DISTRIBUTION OF ANNUAL RAINFALL (INCHES) IN KOLHAPUR DISTRICT.

continued..

TOP