Locations

• alt. Altitude, given in feet above sea level. It is not necessarily the altitude of the weather station, nor even the average altitude of the location. (alt)‒ refers to the highest point in a given location; (alt)+ to the minimum altitude; and (alt)a to the average altitude in locations where there is a significant difference between the lowest and highest altitude.

• location AP airport; NP National Park.

• zone The zone or coldest month of the year is in bold print. The summer-zone (warmest month) follows.

• grade The second number sometimes appearing immediately after the precipitation grade represents annual snowfall and is actually a zone number whereby, for example, “1” equals any climate having over 3 inches up to 1 foot/yr of snow on average. Snowfall totals are frequently absent in the source material.

• The summer grade is always regarded as June, July and August in the northern hemisphere and December, January, and February in the southern hemisphere. In a fairly small number of cases, mostly involving mediterranean climates, summer is represented by July, August, and September in the northern hemisphere and January, February, March in the southern hemisphere. These are more in line with astronomical summer and are indicated by (summer-grade)a.

• climate The climate is identified as the temperature zone + precipitation and aridity indexes. If the temperature index indicates a different range, the name of the climate is modified by either a +, ‒, ‡ (double plus), or = (double minus) sign, for example, “+ temperate”, meaning a temperate zone and a subtropical grade or index.

• % aridity index; it is only exactly comparable between countries using the same definition of a precipitation day. The definition of a precipitation day also affects the grade and climate description, but much less so since the grade has been rounded off. An international standard is very much wanting here; 0.01” (= 0.04 mm; US), 0.2 mm (= 0.0078”; Canada), 0.5 mm (= 0.019”; Japan) work very well and are more or less compatible.

• R geographic climate region, a super-general pattern of precipitation and, in some cases, temperature. These can be subdivided according to the needs of the user.

S = snow or ice cap, whether or not these are present on the surface; T = tundra; B = boreal forest; O = oceanic; M = mediterranean (dry summer); C = central (wetter summer) and an aridity index over 16.6% for the year—if tropical, the dry season can occur in any part of the year; E = eastern or, if tropical, equatorial—a humid grade with an aridity percentage up to 16.6%; D = desert (but not in the case of the tundra or ice cap).

Designations according to altitude are not listed but are conveniently and tentatively identified for descriptive purposes only since the climate, although affected by altitude, is already defined independently. The snow or ice cap is frozen all year. In the tropics it usually begins around 15,000 feet above sea level and in the polar regions in can be found at and above sea level. In our model “alpine” is used to designate both the tundra (which includes alpine meadows) and the boreal forests whenever elevation is involved, typically anything over 3450 feet or 1050 meters above sea level. If the climate is not specifically alpine it is called subalpine through to the cold temperate range. The rest of the temperate category, the subtropical and tropical highlands are simply highlands, for example, a tropical highland; a cool tropical highland. Again, for descriptive purposes mostly, the uplands range from 2300 to 3450’; the midlands from 1150 to 2300’; and the lowlands from 0 to 1150’.

• SH average annual sunshine hours‒another often widely divergent statistic.

• tg temperature grade or warmth index based on biotemperature.