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Monthly climate in Ilam, Nepal

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Ilam features a humid subtropical climate (Cwa). Temperatures typically range between 9 °C (49 °F) and 22 °C (73 °F) through the year, but rarely can drop to -1 °C (31 °F) or can rise to as high as 30 °C (86 °F). The average annual precipitation amounts to about 3390 mm (133.5 inches) and receives 239 rainy days on the 1 mm (0.04 inches) threshold annually. Ilam enjoys an average of 3421 hours of sunshine throughout the year, and daylight varies from 10 hours 27 minutes to 13 hours 47 minutes per day.

Monthly average temperatures in Ilam, Nepal

The warmest months in Ilam are June, July and August, with daily mean temperatures ranging from 22 to 22 °C (72 - 73 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 9 to 11 °C (49 - 52 °F) throughout the day. On average each year, Ilam experiences 74 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 Ilam. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum22°C
(71°F)		22°C
(73°F)		27°C
(82°F)		28°C
(82°F)		29°C
(84°F)		29°C
(84°F)		30°C
(85°F)		30°C
(86°F)		29°C
(85°F)		28°C
(83°F)		26°C
(79°F)		22°C
(72°F)
Mean maximum19°C
(67°F)		21°C
(69°F)		25°C
(76°F)		26°C
(79°F)		27°C
(81°F)		28°C
(82°F)		28°C
(83°F)		29°C
(84°F)		28°C
(83°F)		27°C
(80°F)		24°C
(75°F)		21°C
(69°F)
Average high15°C
(60°F)		17°C
(63°F)		21°C
(69°F)		23°C
(73°F)		24°C
(75°F)		25°C
(78°F)		25°C
(77°F)		25°C
(78°F)		25°C
(77°F)		24°C
(75°F)		21°C
(70°F)		17°C
(63°F)
Daily mean9°C
(49°F)		11°C
(52°F)		15°C
(59°F)		18°C
(64°F)		20°C
(68°F)		22°C
(72°F)		22°C
(72°F)		22°C
(73°F)		21°C
(71°F)		19°C
(66°F)		14°C
(58°F)		11°C
(51°F)
Average low5°C
(41°F)		6°C
(44°F)		10°C
(50°F)		13°C
(56°F)		16°C
(62°F)		19°C
(67°F)		20°C
(69°F)		20°C
(69°F)		19°C
(67°F)		15°C
(59°F)		9°C
(49°F)		6°C
(43°F)
Mean minimum1°C
(34°F)		2°C
(36°F)		6°C
(43°F)		10°C
(50°F)		13°C
(56°F)		17°C
(63°F)		19°C
(67°F)		19°C
(66°F)		17°C
(63°F)		11°C
(51°F)		7°C
(44°F)		3°C
(37°F)
Minimum0°C
(33°F)		-1°C
(31°F)		2°C
(37°F)		8°C
(46°F)		12°C
(53°F)		16°C
(61°F)		19°C
(66°F)		19°C
(66°F)		16°C
(62°F)		9°C
(48°F)		5°C
(42°F)		1°C
(35°F)

Compare climate in Ilam with other places

Compare temperature, precipitation, sunshine, UV index in Ilam, Nepal with other places around the world.

Monthly average precipitation in Ilam, Nepal

Ilam usually has the most precipitation in June, July and August, with an average of 30 rainy days and 685 mm (27.0 inches) of precipitation per month. The driest months in Ilam are January, November and December. On average, 21 mm (0.8 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Ilam. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)27 (1.1)64 (2.5)142 (5.6)210 (8.3)299 (11.8)511 (20.1)940 (37.0)605 (23.8)375 (14.8)180 (7.1)19 (0.8)18 (0.7)
Average precipitation days (≥ 1 mm)713202429293031282053

Monthly sunshine hours in Ilam, Nepal

The sunniest months in Ilam are April, May and October, when the sun shines an average of 10 hours 40 minutes a day. Least sunny months in Ilam: January, July and August receive an average of 7 hours 26 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Ilam. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours236271320324336309216238261320292291
Mean daily daylight hours10h 38m11h 14m12h 0m12h 47m13h 27m13h 47m13h 37m13h 2m12h 17m11h 29m10h 48m10h 27m

Solar UV radiation in Ilam, Nepal

Ilam experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 14 - 15, which corresponds to the Extreme category of sun exposure. January, February and December are in the High exposure category. In these months, the maximum values of the UV index do not exceed 7. For more detailed information, check out our hourly Ilam UV Index data.

Average daily maximum UV levels by month for Ilam. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)6791112141514121086