Climate of Madrid

Madrid and its metropolitan area has a cold semi-arid climate (Köppen climate classification: BSk) which transitions to a mediterranean climate (Csa) on the western half of the city. According to the Troll-Paffen climate classification, Madrid has warm-temperate subtropical climate (Warmgemäßigt-subtropisches Zonenklima) and according to the Siegmund/Frankenberg climate classification, Madrid has a subtropical climate. Madrid has hot summers and relatively cool winters with somewhat frequent frosts (15 days have lows under 0 C on average) and occasional snowfalls, with 3-4 snowy days on average.

Spring
Late Spring, in the months of May and June, is witness to the peak of pollinization of Gramineae, the main culprit behind rhinitis and bronchial asthma in Madrid. Years with high concentrations have proven a public health issue, with punctual cases of asthma epidemics among the inhabitants of Madrid in the aforementioned months.

Sunshine and UV index
Sunshine duration is 2,769 hours per year, from 124 (4 hours per day in average) in December to 359 (above 11.6 hours per day in average) in July. This is one of the largest number of sunshine duration hours in Europe and this is a bit above average for the southern half of Europe because in this part of the continent, sunshine duration varies from about 2,000 to about 3,000 hours per year. However, this is 70% larger value than in northern half of Europe, where sunshine duration is around 1500 hours per year. In winter Madrid has about three times more sun duration than in the northern half of Europe. Madrid has the second highest UV value among continental European capitals after Athens and Lisbon. The values are close to that of Pittsburgh, Pennsylvania as ultraviolet radiation suffers little interference from other geographic variables. Although values are still average, which is not as risky as almost the entire continent, except the afternoons of the warmer months, where exposure should be reduced. The amount varies from 2 between November and January to 9 between June and July.

Precipitation
Madrid has on average only 63 precipitation days a year, therein average several rainy days per month (≥ 1 mm), ranging from 2 days in July and August to 8 days in May. The average annual precipitation is less than 421 mm (16.6 inches) on the center and around 371 mm (14.6 inches) on airport on eastern half of the city. Madrid is the European capital with the least annual precipitation, as well as the only with a semi-arid climate

Humidity
Average relative humidity is 57%, ranging from 38% in July to 74% in December.

Snow
Snowfalls are occasional, happening only a few days per year. In January 1941 8 snow days were recorded, the most for any month.

From 7 January to 10 January 2021, Madrid received the most snow in its recorded history; Spain's meteorological agency AEMET reported between 50 and 60 cm of accumulated snow at its weather stations within the city.

Temperature extremes
The highest temperature recorded during the day at the Retiro station is 40.7 °C on both 28 June 2019, 14 August 2021, and 14 July 2022. Higher maximum temperatures have been recorded in other stations.

The August 1933 reported record had the average maximum temperature during the day at 35.5 °C. The coldest temperature recorded was -10.1 °C at night on 16 January 1945.

Daylight
Madrid, as well as the rest of Spain (except the Canary Islands), are in the UTC +1 time zone and UTC +2 in summer time. Sunrise and sunset occur relatively late compared to other countries in southern Europe or even slightly higher latitudes. Madrid enjoys one of the most optimal number of hours of daylight in Europe. Days in winter are not as short as in the northern part of the continent, the average hours of daylight in December, January and February is 10 hours (for comparison: London or Moscow or Warsaw - about 8 hours), and it is the European capital with the latest sunsets during winter. During the summer, the days have an average length of 14 hours, being the European capital with the latest sunrises in summer, as well as the capital with the latest sunset in southern Europe. Sunset occurs after 21:00 (9:00 pm) throughout most of the summer.