With a yearly precipitation of just 200 mm (7.9 in) and with only 26 days of precipitation, Almería is the only city in Europe with a true hot desert climate (BWh) according to the Köppen climate classification, although it borders a hot semi-arid climate (BSh). Almería is the only European city with this type of climate, also being one of the driest zones on both shores of the Mediterranean coast. Almería has an annual temperature of 19.1 °C (66.4 °F)
The BWh climate is present in nearby areas of Almería province (such as the Cabo de Gata-Níjar Natural Park, the Andarax/Almanzora river valleys), the only region in Europe to have this climate. With an average annual temperature above 19.1 °C (66.4 °F), it also qualifies as the 2nd warmest city in continental Europe, after Seville, also in Andalusia, Spain. This climatic region spreads along the coastline around Almeria, from approximately Almerimar to the southwest, to Torrevieja to the northeast. The nearby Faro del Cabo has the lowest annual precipitation on the European continent (156mm per year).
Almeria also experiences the warmest winters of any city on the European continent with a population over 100,000, and hot and dry summers with no precipitation between June and August. Almería enjoys about 2994 hours of sunshine annually with over 320 sunny days a year on average (6 hours of sunshine in January and 12 in July), making Almería the sunniest city in Europe.
Almería is unique, for a city in Continental Europe, for not having any registered temperature under the freezing mark in its recorded weather history. The coldest temperature recorded was 0.2 °C (32.4 °F) on 9 February 1935. The city of Almería has a very warm climate for its latitude, as it has a very similar climate to Alexandria, in Egypt, which is located further south at 31ºN latitude.
During the winter, daily maximum temperatures tend to stay around 18 °C (64 °F). At night, the temperature very rarely drops below 8 °C (46 °F). The dry season (although there is no real wet season) occurs during the hottest months, as in the Mediterranean climate. Due to the fact there is no real wet season, precipitation even during the wettest months is rare, this falls in short showers or thunderstorms, most likely due to the rain shadow effect. Inland areas of the Almería province have reached 50 °C (122 °F) in summer.
During the warmest months - July and August, the sky is clear and sunny and no rainfall occurs. The typical daily temperatures are around 33 °C (91 °F) during the heat of the day often rising to 38 °C (100 °F) or higher. The minimum temperatures stay around 24 °C (75 °F) during July and August. As is the case for most of coastal Iberia, heatwaves in Almería are less common than in the interior; The hottest temperature recorded was 43 °C (109 °F) in August 2011.
In 2000, a team of geologists found a cave filled with giant gypsum crystals in an abandoned silver mine near Almería. The cavity, which measures 8 x 1.8 x 1.7 metres, may be the largest geode ever found. The entrance of the cave has been blocked by five tons of rocks, and is under police protection (to prevent looters from entering). According to geological models, the cave was formed during the Messinian salinity crisis 6 million years ago, when the Mediterranean sea evaporated and left thick layers of salt sediments (evaporites). The cave is currently not accessible to tourists.