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Monthly climate in San Juan, Peru

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification San Juan features a cold desert climate (BWk). Temperatures typically range between 14 °C (58 °F) and 21 °C (71 °F) through the year, but rarely can drop to 11 °C (52 °F) or can rise to as high as 28 °C (83 °F). The average annual precipitation amounts to about 84 mm (3.3 inches) and receives 11 rainy days on the 1 mm (0.04 inches) threshold annually. San Juan enjoys an average of 3739 hours of sunshine throughout the year, and daylight varies from 11 hours 12 minutes to 13 hours 0 minutes per day.

Monthly average temperatures in San Juan, Peru

The warmest months in San Juan are January, February and March, with daily mean temperatures ranging from 21 to 21 °C (70 - 71 °F) throughout the day. The coldest temperatures usually occur in July, August and September, when daily mean temperatures range from 14 to 15 °C (58 - 59 °F) throughout the day. On average each year, San Juan experiences 18 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in San Juan. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum28°C
(83°F)		27°C
(81°F)		27°C
(81°F)		25°C
(76°F)		23°C
(74°F)		20°C
(68°F)		19°C
(67°F)		19°C
(67°F)		19°C
(67°F)		22°C
(71°F)		22°C
(72°F)		23°C
(75°F)
Mean maximum26°C
(79°F)		26°C
(78°F)		26°C
(79°F)		24°C
(75°F)		21°C
(71°F)		19°C
(66°F)		18°C
(65°F)		18°C
(65°F)		19°C
(66°F)		20°C
(68°F)		21°C
(70°F)		23°C
(74°F)
Average high23°C
(74°F)		24°C
(76°F)		24°C
(75°F)		22°C
(72°F)		20°C
(68°F)		18°C
(65°F)		17°C
(63°F)		17°C
(62°F)		17°C
(63°F)		18°C
(65°F)		20°C
(67°F)		21°C
(71°F)
Daily mean21°C
(70°F)		21°C
(71°F)		21°C
(70°F)		19°C
(67°F)		17°C
(63°F)		16°C
(61°F)		15°C
(59°F)		14°C
(58°F)		15°C
(58°F)		15°C
(60°F)		17°C
(63°F)		19°C
(66°F)
Average low19°C
(67°F)		20°C
(68°F)		19°C
(67°F)		17°C
(63°F)		15°C
(60°F)		14°C
(58°F)		13°C
(56°F)		13°C
(55°F)		13°C
(55°F)		14°C
(57°F)		15°C
(60°F)		17°C
(63°F)
Mean minimum18°C
(64°F)		19°C
(66°F)		18°C
(64°F)		16°C
(61°F)		14°C
(57°F)		13°C
(56°F)		12°C
(53°F)		11°C
(53°F)		12°C
(53°F)		13°C
(55°F)		14°C
(57°F)		15°C
(60°F)
Minimum17°C
(63°F)		17°C
(62°F)		16°C
(61°F)		14°C
(58°F)		12°C
(54°F)		13°C
(55°F)		11°C
(53°F)		11°C
(52°F)		11°C
(53°F)		12°C
(54°F)		13°C
(56°F)		15°C
(59°F)

Compare climate in San Juan with other places

Compare temperature, precipitation, sunshine, UV index in San Juan, Peru with other places around the world.

Monthly average precipitation in San Juan, Peru

San Juan usually has the most precipitation in January, February and July, with an average of 2 rainy days and 12 mm (0.5 inches) of precipitation per month. The driest months in San Juan are March, April and November. On average, 4 mm (0.2 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in San Juan. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)14 (0.6)11 (0.4)5 (0.2)3 (0.1)5 (0.2)9 (0.4)11 (0.4)6 (0.2)6 (0.2)5 (0.2)4 (0.2)6 (0.2)
Average precipitation days (≥ 1 mm)431002100000

Monthly sunshine hours in San Juan, Peru

The sunniest months in San Juan are October, November and December, when the sun shines an average of 10 hours 52 minutes a day. Least sunny months in San Juan: January, February and June receive an average of 9 hours 23 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in San Juan. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours261292323312315290304319317335331334
Mean daily daylight hours12h 54m12h 34m12h 8m11h 43m11h 22m11h 12m11h 18m11h 36m12h 0m12h 26m12h 49m13h 0m

Solar UV radiation in San Juan, Peru

San Juan experiences the highest level of ultraviolet (UV) radiation in January, November and December, when the maximum UV index can reach values of 15 - 15, which corresponds to the Extreme category of sun exposure. May, June and July are in the Very High exposure category. In these months, the maximum values of the UV index do not exceed 10. For more detailed information, check out our hourly San Juan UV Index data.

Average daily maximum UV levels by month for San Juan. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)1515141310991113141515