Wednesday, March 14, 2018

Book: Charleston & SC 18th Century Weather, Ramsay SC Vol II





Ramsay on Google Books   

General:
South-Carolina extends about 200 miles on the sea coast, and about 300 to the west. The southern boundary and a great part of the northern, runs north-west from the Atlantic ocean. As the air grows colder in a western as well as a northern direction, the climate is far from being uniform.

3 Weather Patterns in the State
The western districts, from their high and dry situation and contiguity to the mountains; enjoy a dry, elastic, wholesome atmosphere. The middle country par takes of the advantages of the upper country, and the disadvantages of the lower. The latter being intersected by swamps, bays, and low grounds, the waters spread over the face of the country, and in consequence of heat and stagnation produce mephitic exhalations.

Lowland Fog
Thick fogs cover the low lands throughout the night during the summer months. In the western districts from August until frost, thick fogs also cover the grounds at night, but are dissipated by the rays of the sun. Much exposure to these fogs early in the morning is said to occasion intermittents.

Since 1791 the difference between our coolest and warmest summers has ranged between 88 and 93, and the difference between our mildest and coldest winters has ranged on a few particular days from 50 to 17.

Our greatest heat is sometimes less and never much more than what takes place in the same season in Baltimore, Philadelphia, and New- York, but the warm weather in these places does not on an average continue above six weeks, while in Carolina it lasts from three to four months. Our nights are also warmer than theirs.

The heat of the days in Charlestown is moderated by two causes, which do not exist in an equal degree to the northward of it. Our situation, open and near the sea, almost surrounded by water and not far distant from the torrid zone, gives us a small proportion of the trade winds which, blowing from the south-east, are pleasantly cool. These generally set in about 1 0 A. M. and continue for the remainder of the day.

A second reason may be assigned from the almost daily showers of rain which fall in the hottest of our summer months, and are frequently accompanied with much thunder and lightning, and therefore are called thunder showers.

The interior of SC, not getting the benefit of the coastal winds, tends to run 8 to 10 degrees hotter than Charleston.

The number of extreme warm days in Charlestown is seldom above thirty in a year ; and it is rare for three of these to follow each other. On the other hand, eight months out of twelve are moderate and pleasant.

The number of piercing cold days in winter is more in proportion to our latitude than of those which are distressingly hot in summer : but of these more than three rarely come together.

There are on an average in Charlestown about twenty nights, in a twelvemonth, in which the closeness and sultriness of the air forbid in a great measure the" refreshment of sound sleep ; but this severe weather is for the most part soon terminated by refreshing and cooling showers.

April, May, and June are in common our healthiest months, with the exception of the cholera infantum and bowel diseases among children. August and September are the most sick ly ;

April and May the driest ; June, July, and Au gust the wettest ; November the pleasantest.

Our old people are oftenest carried off in cold weather ; the young, the intemperate, and the laboring part of the community, when it is hot.

In some years Jan uary, and in others February is the coldest month. It is remarkable that when orange trees have been destroyed by frost, it has always been in the month of February. It is also remarkable that oranges, though plentiful forty or fifty years ago, are now raised with difficulty. Once in every eight or ten years a severe winter destroys the trees on which they grow. Of this kind were the winters of 1766, ,1779, 1786, and 1796.

In winter the mountains near the western boun dary of the state are often covered with snow. From thence to the sea shore snow but seldom falls so as to cover the ground except on extraordinary occasions. The soil is sometimes in like manner bound up with frost. This seldom extends into the ground more than two inches. In shady places it will not thaw for several days ; and the waters and ponds at the same time are generally frozen, but seldom more than half an inch thick, and rarely strong enough to give an opportunity for the w holesome exercise of skaitingi

This freezing lasts only for a few days, and the weather breaks up mild and warm so as to render fires unnecessary in the middle of the day. In the winter these changes from heat to cold, and the reverse, fre quently and suddenly take place, and affect the feelings of the inhabitants much more than equal, or even greater degrees of permanent cold in countries where the climate is more steady, and the transitions from heat to cold are more gradual.

In February the weather is particularly variable. It is often rainy. Vegetation commences in warm clear days and inspires hopes of an early spring. Suddenly a north-west wind inducing frost, some times blasts and always retards these flattering expectations.

Planting Season
In March and April the planting sea son begins and continues till June.

Rains
In July and August the heats increase, and the heavy rains set in attended at times with severe thunder and lightning.

Harvest
September is the principal month of harvest. In it the evenings and mor nings are chilly, but the sun is extremely oppressive in the middle of the day. Storms of rain are produced accompanied sometimes with hurricanes.

Change of Season
In Sept., the leaves of deciduous trees begin to fall, and na ture by degrees assumes the sober dress of winter. In October the weather is generally mild and clear. About the middle of this month frosts commence and generally terminate in the month of March. On their approach they bring with them a cure for the fevers, then usually prevalent.

Fires In The Charleston Fireplaces
The inhabitants of Charlestown keep fires in their houses from four to six months in the year ; but there are some warm days in every one of them in which fires are disagreeable. On the other hand there are some moist cool days in every month of the year, with the exception of July and August, in which fires are not only healthy but pleasant. These, with the addition of June, are the only months which are exempt from frost in all years and in every part of South-Carolina.

Sharp cold weather seldom commences before December, though there are several cold days in November, and the evenings and mornings are generally so. In these two months, especially the last, vegetation is checked and continues so for about four weeks. In this manner the annual circle revolves in the varying climate of South-Carolina. The last half of December and the first half of January is the dullest period of the whole. If the year was to be regulated with a particular reference to Caro lina, it might be said to commence about the middle of January, and to terminate about the middle of December ; for the one begins and the other ends its visible natural vegetation.

1802-Charleston
Month             Days of Rain        Inches
January                     2                    0.4
February                   4                    0.8
March                       3                    0.8
April                         3                    3
May                          7                    3
June                          7                    3.4
July                         14                   12.1
August,                   10                   4,9
September                 5                   5.8
October,                    3                   0.3
November,                1                   3,4
December,                6                   3.3

Wind Direction
Month                S. to NW           N to SE
January                  17                      14
February                15                      13
March                    20                      11
April                      22                        8
May                       26                        5
June                       18                      12
July                        21                      10
August,                  16                      15
September             18                       12
October,                  8                        23
November,            14                        16
December,            17                        11

South to NW winds are the tale end of the Trade Winds and moderate the weather. Winds from the North to SE are coming across land and are hotter in the summer, colder in the winter?

From Ramsay: The east and north-east winds in winter and spring are very injurious to invalids, especially to those who have weak lungs or who are troubled with rheu matic complaints. In these seasons they bring with them that languor for which they are remarkable in other countries ; but in summer, by moderating heat they are both pleasant and wholesome. Their worst effects are to produce catarrhal complaints and colds. Winds from the north-west to the south west, blowing over large tracts of marsh or swamp, are in summer season unfriendly to health. The north and north-west winds in winter, are remarkable for their invigorating effects on the human frame. South winds are healthy in summer, but much less so in winter.

Snow is more common and continues longer in proportion as we recede from the sea shore. The further we proceed westward till we reach the mountains which divide the western from the eastern waters, the weather is colder in the winter and ve getation later in the spring. In the western parts of the state the days are warmer and the nights are cooler than on the sea coast. While the inhabitants of Charlestown can scarcely bear to be covered in the hours of sleep with a sheet, they who live in the town of Columbia, one hundred and twenty computed miles, but probably about one hundred in a straight line, to the north-west of it, are not incommoded by a blanket : and this difference is greater as we advance more to the west.

The latest frost in the spring of 1802 was March the 15th ; the earliest in autumn was October 26th or rather November.l st. The coldest day was February 23d. Thermometer 32. The next coldest day was December 9th, thermometer 33.

The greatest and least average degrees of heat in each month was as fol lows': Greatest. Least.

January          74 45
February,       69 32
March,           74 44
April,             86 61
May,              84 66
June,              86 73
July,               87 70
August,          89 72
September,     89 60
October,         81 54
November,     74 49
December,     70 33


The medium temperature of the well water in Charlestown is 65'. This is twelve degrees above that of the well-water of Philadelphia.

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