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Monthly climate in Alter do Chao, Portugal

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Alter do Chao features a hot-summer Mediterranean climate (Csa). Temperatures typically range between 9 °C (48 °F) and 24 °C (76 °F) through the year, but rarely can drop to -2 °C (28 °F) or can rise to as high as 44 °C (111 °F). The average annual precipitation amounts to about 562 mm (22.1 inches) and receives 72 rainy days on the 1 mm (0.04 inches) threshold annually. Alter do Chao enjoys an average of 3753 hours of sunshine throughout the year, and daylight varies from 9 hours 26 minutes to 14 hours 52 minutes per day.

Monthly average temperatures in Alter do Chao, Portugal

The warmest months in Alter do Chao are July, August and September, with daily mean temperatures ranging from 22 to 24 °C (73 - 76 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 9 to 11 °C (48 - 53 °F) throughout the day. On average each year, Alter do Chao experiences 122 days above 25 °C (77.0 °F) and 1 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Alter do Chao. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum20°C
(69°F)		23°C
(74°F)		27°C
(81°F)		29°C
(85°F)		35°C
(95°F)		42°C
(108°F)		41°C
(106°F)		44°C
(111°F)		37°C
(99°F)		35°C
(95°F)		26°C
(78°F)		19°C
(67°F)
Mean maximum18°C
(65°F)		21°C
(71°F)		24°C
(76°F)		27°C
(81°F)		33°C
(91°F)		36°C
(97°F)		39°C
(102°F)		40°C
(104°F)		36°C
(97°F)		31°C
(89°F)		22°C
(73°F)		19°C
(66°F)
Average high14°C
(57°F)		16°C
(62°F)		18°C
(64°F)		20°C
(68°F)		25°C
(77°F)		28°C
(83°F)		32°C
(90°F)		33°C
(92°F)		30°C
(85°F)		25°C
(76°F)		17°C
(63°F)		15°C
(59°F)
Daily mean9°C
(48°F)		11°C
(53°F)		13°C
(55°F)		15°C
(59°F)		19°C
(66°F)		21°C
(70°F)		24°C
(75°F)		24°C
(76°F)		22°C
(73°F)		18°C
(65°F)		13°C
(55°F)		11°C
(52°F)
Average low5°C
(42°F)		7°C
(46°F)		8°C
(47°F)		10°C
(50°F)		13°C
(55°F)		15°C
(59°F)		17°C
(62°F)		17°C
(63°F)		16°C
(62°F)		13°C
(56°F)		9°C
(49°F)		7°C
(46°F)
Mean minimum0°C
(33°F)		3°C
(37°F)		3°C
(38°F)		5°C
(42°F)		7°C
(45°F)		11°C
(51°F)		12°C
(54°F)		13°C
(56°F)		11°C
(53°F)		7°C
(45°F)		4°C
(39°F)		2°C
(36°F)
Minimum-2°C
(28°F)		0°C
(33°F)		1°C
(35°F)		3°C
(38°F)		5°C
(41°F)		8°C
(47°F)		11°C
(53°F)		12°C
(55°F)		9°C
(49°F)		5°C
(40°F)		2°C
(35°F)		-1°C
(30°F)

Compare climate in Alter do Chao with other places

Compare temperature, precipitation, sunshine, UV index in Alter do Chao, Portugal with other places around the world.

Monthly average precipitation in Alter do Chao, Portugal

Alter do Chao usually has the most precipitation in March, April and November, with an average of 10 rainy days and 85 mm (3.4 inches) of precipitation per month. The driest months in Alter do Chao are June, July and August. On average, 8 mm (0.3 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Alter do Chao. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)40 (1.6)52 (2.0)92 (3.6)84 (3.3)37 (1.4)14 (0.6)4 (0.2)5 (0.2)29 (1.1)52 (2.1)80 (3.2)73 (2.9)
Average precipitation days (≥ 1 mm)57912551135118

Monthly sunshine hours in Alter do Chao, Portugal

The sunniest months in Alter do Chao are May, June and July, when the sun shines an average of 13 hours 26 minutes a day. Least sunny months in Alter do Chao: January, February and December receive an average of 6 hours 37 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Alter do Chao. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours175218290338401404429401349313220208
Mean daily daylight hours9h 45m10h 43m11h 58m13h 14m14h 19m14h 52m14h 34m13h 37m12h 23m11h 7m10h 0m9h 26m

Solar UV radiation in Alter do Chao, Portugal

Alter do Chao experiences the highest level of ultraviolet (UV) radiation in May, June and August, when the maximum UV index can reach values of 10 - 11, which corresponds to the Very High / Extreme category of sun exposure. January, February and December are in the Moderate exposure category. In these months, the maximum values of the UV index do not exceed 4. For more detailed information, check out our hourly Alter do Chao UV Index data.

Average daily maximum UV levels by month for Alter do Chao. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)3469101110108643