ST. HELENA, SAINT HELENA

This climate is dominated in all months by the subtropical anticyclon, or subtropical high, with its descending air, elevated inversions, and clear skies. Such an atmospheric environment inhibits precipitation. Most of Earth's tropical, true desert climates occur between 15° and 30° latitude. The most extreme arid areas also are far removed from sources of moisture-bearing winds in the interiors of continents and are best developed on the western sides of continents, where the subtropical anticyclone shows its most intense development. An exception to the general tendency for aridity to be associated with subsidence is in the Horn of Africa region, where the dryness of Somalia is caused more by the orientation of the landmass in relation to the atmospheric circulation. Both the high- and low-sun monsoonal winds blow parallel to the coast, so that moisture-laden maritime air can penetrate over land only infrequently.

The Köppen Climate Classification subtype for this climate is "Bwh". (Tropical and Subtropical Desert Climate).

The average temperature for the year in St. Helena is 65.0°F (18.3°C). The warmest month, on average, is February with an average temperature of 70.0°F (21.1°C). The coolest month on average is August, with an average temperature of 61.0°F (16.1°C).

The highest recorded temperature in St. Helena is 90.0°F (32.2°C), which was recorded in January. The lowest recorded temperature in St. Helena is 52.0°F (11.1°C), which was recorded in August.

There are an average of 212.0 days of precipitation, with the most precipitation occurring in October with 21.0 days and the least precipitation occurring in January with 15.0 days.

In terms of liquid precipitation, there are an average of 212.0 days of rain, with the most rain occurring in October with 21.0 days of rain, and the least rain occurring in January with 15.0 days of rain.