nomadseason

Monthly climate in Decatur, Indiana, United States

Last updated: March 2, 2024

Under the Köppen–Geiger climate classification Decatur features a humid continental climate (Dfa). Temperatures typically range between -2 °C (29 °F) and 25 °C (76 °F) through the year, but rarely can drop to -25 °C (-13 °F) or can rise to as high as 36 °C (97 °F). The average annual precipitation amounts to about 1102 mm (43.4 inches) and receives 134 rainy days on the 1 mm (0.04 inches) threshold annually. Decatur enjoys an average of 2806 hours of sunshine throughout the year, and daylight varies from 9 hours 16 minutes to 15 hours 2 minutes per day.

Monthly average temperatures in Decatur, Indiana, United States §

The warmest months in Decatur are June, July and August, with daily mean temperatures ranging from 22 to 25 °C (73 - 76 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -2 to 2 °C (29 - 35 °F) throughout the day. On average each year, Decatur experiences 96 days above 25 °C (77.0 °F) and 95 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Decatur, Indiana, 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 18°C
(64°F)		 22°C
(73°F)		 25°C
(76°F)		 29°C
(84°F)		 34°C
(94°F)		 34°C
(94°F)		 36°C
(97°F)		 35°C
(95°F)		 33°C
(92°F)		 33°C
(91°F)		 26°C
(80°F)		 17°C
(63°F)
Mean maximum 14°C
(58°F)		 17°C
(63°F)		 21°C
(69°F)		 27°C
(80°F)		 31°C
(88°F)		 33°C
(92°F)		 33°C
(92°F)		 32°C
(91°F)		 32°C
(90°F)		 30°C
(86°F)		 19°C
(67°F)		 16°C
(61°F)
Average high 2°C
(36°F)		 4°C
(39°F)		 10°C
(51°F)		 16°C
(60°F)		 22°C
(72°F)		 27°C
(81°F)		 29°C
(85°F)		 28°C
(83°F)		 26°C
(79°F)		 19°C
(66°F)		 9°C
(49°F)		 6°C
(43°F)
Daily mean -2°C
(29°F)		 -0°C
(32°F)		 5°C
(41°F)		 10°C
(51°F)		 17°C
(63°F)		 22°C
(73°F)		 25°C
(76°F)		 23°C
(74°F)		 20°C
(69°F)		 14°C
(57°F)		 5°C
(42°F)		 2°C
(35°F)
Average low -5°C
(23°F)		 -4°C
(24°F)		 0°C
(33°F)		 5°C
(42°F)		 12°C
(54°F)		 18°C
(64°F)		 20°C
(68°F)		 18°C
(65°F)		 15°C
(60°F)		 9°C
(49°F)		 1°C
(34°F)		 -2°C
(28°F)
Mean minimum -19°C
(-1°F)		 -17°C
(2°F)		 -9°C
(16°F)		 -5°C
(24°F)		 2°C
(37°F)		 12°C
(53°F)		 14°C
(58°F)		 12°C
(54°F)		 8°C
(46°F)		 0°C
(32°F)		 -8°C
(18°F)		 -12°C
(10°F)
Minimum -25°C
(-13°F)		 -22°C
(-8°F)		 -13°C
(9°F)		 -7°C
(20°F)		 -1°C
(30°F)		 8°C
(47°F)		 11°C
(52°F)		 9°C
(49°F)		 4°C
(39°F)		 -2°C
(29°F)		 -16°C
(4°F)		 -22°C
(-7°F)

Compare climate in Decatur with other places

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

Monthly average precipitation in Decatur, Indiana, United States §

Decatur usually has the most precipitation in May, June and July, with an average of 13 rainy days and 114 mm (4.5 inches) of precipitation per month. The driest months in Decatur are January, September and December. On average, 69 mm (2.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Decatur, Indiana, 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) 74 (2.9) 83 (3.3) 100 (4.0) 91 (3.6) 124 (4.9) 114 (4.5) 102 (4.0) 99 (3.9) 68 (2.7) 98 (3.9) 82 (3.2) 64 (2.5)
Average precipitation days (≥ 1 mm) 8 12 12 12 14 13 13 12 8 12 9 9

Monthly sunshine hours in Decatur, Indiana, United States §

The sunniest months in Decatur are June, July and August, when the sun shines an average of 10 hours 43 minutes a day. Least sunny months in Decatur: January, February and December receive an average of 4 hours 42 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Decatur, Indiana, 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 109 160 219 226 266 318 344 322 278 225 174 159
Mean daily daylight hours 9h 36m 10h 39m 11h 58m 13h 19m 14h 28m 15h 2m 14h 43m 13h 42m 12h 24m 11h 3m 9h 53m 9h 16m

Solar UV radiation in Decatur, Indiana, United States §

Decatur experiences the highest level of ultraviolet (UV) radiation in April, June and July, when the maximum UV index can reach values of 9 - 10, which corresponds to the Very High 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 Decatur UV Index data.

Average daily maximum UV levels by month for Decatur, Indiana, 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 6 9 9 10 10 9 8 6 4 2

Detailed Monthly Weather Insights for Decatur, Indiana, United States

Discover in-depth weather details for every month in Decatur. Click through the links below for comprehensive overviews of temperature trends, precipitation levels, sunshine hours, and solar UV radiation specifics. Whether planning a visit or simply curious about Decatur's climate nuances, these monthly breakdowns provide the information you need for an informed understanding of what to expect throughout the year.

Each link leads to a detailed account of the typical weather conditions for that month, providing both locals and tourists with vital information to plan their daily activities, wardrobe, and travel itineraries accordingly.