So were early autumn frosts and late spring freezes.
It does not, however, prevail for long, and in the first half of September frosts begin on the middle Urals.
At the head of the Humboldt river frosts are of almost nightly occurrence, and in the Carson Valley damaging frosts often occur in June.
Coccinea, often confounded with the red oak, but with larger leaves, with long lobes ending in several acute points; they change to a brilliant scarlet with the first October frosts, giving one of the most striking of the various glowing tints that render the American forests so beautiful in autumn.
The young trees require protection from storms and late frosts even more than in England; the red pine of the north-eastern states, Pinus resinosa, answers well as a nurse, but the pitch pine and other species may be employed.
Throughout the region north of the Apennines no plants will thrive which cannot stand occasional severe frosts in winter, so that not only oranges and lemons but even the olive tree cannot be grown, except in specially favoured situations.
From it in the fertile valley of Avellino, of no great elevation, but encircled by high mountains, light frosts are not uncommon as late as June; and 18 m.
High districts covered with oaks and chestnuts succeed to this almost tropical vegetation; a little higher up and we reach the elevated regions of the Pollino and the Sila, covered with firs and pines, and affording rich pastures even in the midst of summer, when heavy dews and light frosts succeed each other in July and August, and snow begins to appear at the end of September or early in October.
Equally disastrous are those climatic or seasonal changes which involve temperatures in themselves not excessive but in wrong sequence; how many more useful plants could be grown in the open in the United Kingdom if the deceptively mild springs were not so often followed by frosts in May and June!
The extreme frosts and heats of the English climate are unknown, but occasional heavy snow-falls occur, and the sea in shallow inlets is covered with a thin coating of ice.
Even in summer cold and thick fogs are often seen hanging over the rivers, and clinging to the lower parts of the hills, and hoar-frosts are by no means unknown even in June and July.
In the tropics the essential requirements are very similar, but there the dry season checks production in much the same way as do the frosts in temperate climates.
On the plains bordering the Rio Grande frosts are frequent.
Frosts of - 13° to - 18° F.
More dreaded than the frosts are the terrible burans or snowstorms, which occur in early spring and destroy thousands of horses and cattle that have been grazing on the steppes throughout the winter.
Still, at many places night frosts set in as early as the second half of July.
On the lower plateau, in Transbaikalia, grain is successfully raised in the Nerchinsk region, with serious risks, however, from early frosts in the valleys.
There are occasional frosts, but snow is never seen.
Coffee naturally occupies first place, and is grown wherever frosts are not severe from the Amazon south to Parana.
The midday temperatures recorded by Huber at Hail during January and the first half of February average about 65° F., and water froze on several nights; at Medina the winters are cold and night frosts of frequent occurrence, and these conditions prevail over all the western part of the Nejd plateau.
Autumn begins in Sept., light frosts occurring at its close.
Both of these plains are so level, and have so fertile a soil that they are the seats of extensive agriculture, especially fruit raising, which is further encouraged by the influence of the large bodies of lake water that moderate the heat of summer and the cold of winter, and tend to check the late frosts of spring and the early frosts of autumn.
In most of the state frosts begin from September 1st to October 1st, and end from April 1st to May 1st.
Along the whole west coast the climate resembles nothing in the British Islands so much as Cork and Kerry, for there are the same wet gales from a western ocean, the same clouds gathering on the dripping sides of wild mountains, an equal absence of severe frosts and hot sunshine, and a rich and evergreen vegetation.
The climate indeed is noted for its healthiness, the chief drawback being dust-storms. The average temperature for the four winter months - May-August - is 49° F.; hard frosts at night are then common.
Killing frosts often occur in June and return again early in September.
The galls are gathered before the frosts set in, and are exposed to steam to kill the insects."
The climate of this part of the valley is, of course, continental - frosts of - 22° F.
Frosts are frequent, but snow rarely falls.
Above this is the tierra fria, which ranges from 5577 to 8200 ft., and includes all the higher portions of the Mexican plateau, and which corresponds to the temperate regions of Central United States where frosts are very rarely experienced.
The cultivation of osiers is attended with many disturbing causes - winter floods, spring frosts, ground vermin and insect pests of various kinds, sometimes working great havoc to the crop.
While flowers bloom throughout the year at Portland, frosts have occurred in every month of the year at Lakeview, in the Great Basin.
The frosts are severe, the Danube being often icebound for three months.
Killing frosts occur early in September and as late as the last of May, and in the higher valleys they may occur at any time.
In the protected valleys between the high plateaus alluvial soils are cultivated; but the plateau summits are relatively inaccessible, and, being subject to summer frosts, are not cultivated.
The summers are short, there being only about 41 months between frosts even in the southern sections, and the mean summer temperature is about 62° F.
But the Alaska summer is the uncertain season; at times the nights are cold into July, at times snow falls and there are frosts in mid-August; sometimes rain is heavy, or again there is a veritable drought.
The grasses are killed by the frosts in September.
The crop is very uncertain owing to droughts; spring frosts and locusts, and, ' in order to avoid a total failure and to allow time for collecting the produce, there are three sowings at intervals from October to March - the crops thus coming to perfection in succession.
The date palm fruits well; figs grow luxuriantly, though requiring much irrigation; almonds do well if protected from spring frosts; seaisland cotton grows in the finest grades, but is not of commercial importance.
Coca, one of the most important plants of the country, is cultivated on the eastern slopes of the Andes at an altitude of 5000 to 6000 ft., where the temperature is uniform and frosts are unknown.
Frosts are infrequent, and snow does not lie long.