The climate of the Andamans is equatorial in its uniformity, and greatly resembles that of Tenasserim and Mergui. It is not generally healthy for Europeans, but improves from a hygienic point of view when the forest is cleared from any locality. During the first two months of the dry season strong winds blow from the north-east, causing sickness, and damage to vegetation. As the islands are exposed to the full force of the south-west monsoon, only four months of fair weather (January to April) can be counted on. December and January are the coolest months, with a mean temperature of 79° and a mean minimum of 75°, while March and April are the warmest, with means of 82° and 83° respectively, and a mean daily maximum of 92° at Port Blair, where throughout the year the mean is 80°, the highest 96°, and the lowest 66°; so that the absolute range is 30°. The mean diurnal range is as much as 14° to 15° in February, March, and April, while between June and September it is only 8° or 9°. The mean temperature throughout the year is about 80°. The south-west monsoon sets in, accompanied by heavy rain, in the early part of May, but occasionally in April, and lasts till October. March is the driest month, and January and February somewhat less so; but the rainy season lasts from the middle of May till the middle of October, and what is called the moderate season, from October to January. During the latter the average monthly rainfall is about 8 inches; in the rainy season it is 16 inches, with twenty-four rainy days per month; while, on the average, throughout the dry season rain falls on ten days to an extent of 5 inches. At Port Blair the mean humidity is 83 per cent, and the average annual rainfall is 117 inches; but elsewhere it varies from 100 to 155 inches, and there are about 180 wet days in the year. At the change of the monsoons stormy weather is common, and the neighbourhood of the Andamans is considered to be the birthplace of many of the violent cyclones that occasionally visit the Indian and Burmese coasts of the Bay of Bengal. The hurricanes generally both originate either between Ceylon or the N.W. portion of the bay, and take various courses, according to the season; but, although situated near the cradle of these storms, the islands are not often traversed by them. In 1864 one is recorded as having visited the locality, and on the night of November 1st, 1891, a violent cyclone passed over Port Blair, which, after travelling north-westward across the bay, did much further damage at the mouth of the Hugli and on the Orissa coast. The maximum velocity of the wind registered at Port Blair on the latter occasion was 111 miles.