nomadseason

Monthly climate in McLean, Illinois, United States

Last updated: May 6, 2024

Under the Köppen–Geiger climate classification McLean features a humid continental climate (Dfa).Temperatures typically range between -2 °C (28 °F) and 25 °C (77 °F) through the year, but rarely can drop to -28 °C (-19 °F) or can rise to as high as 35 °C (96 °F).The average annual precipitation amounts to about 1160 mm (45.7 inches) and receives 123 rainy days on the 1 mm (0.04 inches) threshold annually.McLean enjoys an average of 2986 hours of sunshine throughout the year, and daylight varies from 9 hours 21 minutes to 14 hours 58 minutes per day.

Monthly average temperatures in McLean, Illinois, United States §

The warmest months in McLean are June, July and August, with daily mean temperatures ranging from 23 to 25 °C (74 - 77 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -2 to 2 °C (28 - 35 °F) throughout the day. On average each year, McLean experiences 110 days above 25 °C (77.0 °F) and 99 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in McLean, Illinois, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to June 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum 17°C
(62°F)		 23°C
(74°F)		 26°C
(78°F)		 29°C
(84°F)		 35°C
(95°F)		 35°C
(95°F)		 34°C
(94°F)		 35°C
(95°F)		 35°C
(96°F)		 32°C
(90°F)		 25°C
(76°F)		 19°C
(67°F)
Mean maximum 14°C
(57°F)		 17°C
(62°F)		 21°C
(71°F)		 28°C
(82°F)		 32°C
(89°F)		 33°C
(91°F)		 33°C
(92°F)		 33°C
(91°F)		 33°C
(92°F)		 31°C
(87°F)		 20°C
(68°F)		 17°C
(64°F)
Average high 2°C
(35°F)		 4°C
(39°F)		 11°C
(52°F)		 16°C
(62°F)		 23°C
(74°F)		 28°C
(84°F)		 29°C
(85°F)		 28°C
(83°F)		 27°C
(81°F)		 19°C
(67°F)		 10°C
(50°F)		 7°C
(44°F)
Daily mean -2°C
(28°F)		 -1°C
(31°F)		 6°C
(43°F)		 11°C
(52°F)		 18°C
(65°F)		 23°C
(74°F)		 25°C
(77°F)		 23°C
(74°F)		 21°C
(71°F)		 14°C
(57°F)		 5°C
(41°F)		 2°C
(35°F)
Average low -6°C
(21°F)		 -6°C
(22°F)		 1°C
(34°F)		 6°C
(43°F)		 13°C
(56°F)		 18°C
(65°F)		 20°C
(68°F)		 18°C
(65°F)		 16°C
(60°F)		 9°C
(48°F)		 0°C
(33°F)		 -3°C
(27°F)
Mean minimum -20°C
(-4°F)		 -20°C
(-4°F)		 -11°C
(13°F)		 -3°C
(27°F)		 4°C
(40°F)		 13°C
(56°F)		 15°C
(59°F)		 12°C
(54°F)		 8°C
(46°F)		 -1°C
(30°F)		 -8°C
(17°F)		 -13°C
(10°F)
Minimum -28°C
(-19°F)		 -25°C
(-14°F)		 -18°C
(0°F)		 -8°C
(18°F)		 -0°C
(32°F)		 10°C
(51°F)		 13°C
(55°F)		 11°C
(52°F)		 5°C
(42°F)		 -5°C
(23°F)		 -13°C
(8°F)		 -20°C
(-4°F)

Compare climate in McLean with other places

Compare temperature, precipitation, sunshine, UV index in McLean, Illinois, United States with other places around the world.

Monthly average precipitation in McLean, Illinois, United States §

McLean usually has the most precipitation in April, May and June, with an average of 13 rainy days and 132 mm (5.2 inches) of precipitation per month.The driest months in McLean are September, November and December. On average, 60 mm (2.4 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in McLean, Illinois, United States.Generated using Copernicus Climate Change Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average precipitation mm (inches) 67 (2.7) 70 (2.7) 121 (4.8) 123 (4.8) 150 (5.9) 123 (4.8) 114 (4.5) 96 (3.8) 62 (2.4) 115 (4.5) 65 (2.6) 54 (2.1)
Average precipitation days (≥ 1 mm) 9 10 11 11 15 13 11 11 6 11 8 7

Monthly sunshine hours in McLean, Illinois, United States §

The sunniest months in McLean are June, July and August, when the sun shines an average of 11 hours 9 minutes a day.Least sunny months in McLean: January, February and December receive an average of 5 hours 23 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in McLean, Illinois, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2017 to January 2022.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean monthly sunshine hours 119 174 218 242 287 337 352 336 291 230 198 197
Mean daily daylight hours 9h 40m 10h 41m 11h 58m 13h 17m 14h 25m 14h 58m 14h 39m 13h 40m 12h 24m 11h 5m 9h 56m 9h 21m

Solar UV radiation in McLean, Illinois, United States §

McLean experiences the highest level of ultraviolet (UV) radiation in May, June and July, when the maximum UV index can reach values of 10 - 11, which corresponds to the Very High / Extreme category of sun exposure.January, November and December are in the Low / 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 McLean UV Index data.

Average daily maximum UV levels by month for McLean, Illinois, United States.Generated using Copernicus Atmosphere Monitoring Service information.Data for period from January 2022 to January 2023.
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
UV Index (month maximum) 3 5 7 9 10 11 10 9 8 6 4 2