Most equable temperature (long period)

The location with the most equable recorded temperature over a long period is Kwajalein in the Marshall Islands, positioned near the equator in the mid Pacific Ocean. Since reliable weather-station measurements have been collected at this site from 1960 onwards, the temperature has not dipped below 20°C (68°F) or risen above 33.3°C (92°F), giving it a spread of just 13.3°C (24°F).

Temperature readings originally started to be collected at Kwajalein in 1952, but there were some initial problems with overexposure that skewed the results; these technological issues had been resolved by 1960.

The Marshall Islands have a tropical climate and are well known for their constant temperatures. Rainfall varies across the archipelago, depending on latitude, but Kwajalein Island towards the south receives as much as 2,500 mm (100 in) of rain per annum.

The most equable temperature in one calendar year is 8.5°C (15.3°F); this was documented in the Cocos Islands, aka Keeling Islands, an Australian territory in the Indian Ocean, in 1981, when the weather station there logged a peak temperature of 30.4°C (86.7°F) and a minimum of 21.9°C (71.4°F).

Another example of extreme temperature consistency was logged in Garapan on Saipan in the Mariana Islands, also in the Pacific Ocean. During the nine years from 1927 to 1935, the lowest temperature recorded was 19.6°C (67.3°F), and the highest was 31.4°C (88.5°F), giving a range of 11.8°C (21.2°F).